I hate it when bugs get in the way of testing!
There are only two poisons that can control scorpions, one is called demon, I can't recall the other one
So the discovery is not with the bullets, but with the barrel?
Michael.... I applaud your drive to get an improvement to market, without any compensation.... It is nice to see somebody else ready to do development and share with the airgunning community without profit being the motive.... We all will benefit in the long run.... To me, that is what it's all about.... 8)
Bob
Michael.... I applaud your drive to get an improvement to market, without any compensation.... It is nice to see somebody else ready to do development and share with the airgunning community without profit being the motive.... We all will benefit in the long run.... To me, that is what it's all about.... 8)
Bob
I completely agree Bob . Mike was nice enough to get me thinking of how it could be done . Once there’s some proof of concept I’m absolutely certain this will work out for a lot of shooters . Not only airgun specific as far as I can tell .
I have sent the idea and how to do it to several people on the forum.
If you have tested it, please tell us the results, without saying yet what it is we are doing. I, we are looking forward to test results.
Mike/Knife
Following to hear the rest of the story.
I have sent the idea and how to do it to several people on the forum.
If you have tested it, please tell us the results, without saying yet what it is we are doing. I, we are looking forward to test results.
Mike/Knife
Looking forward to it improving my P-17Lol ;D
Looking forward to it improving my P-17
I’ve seen enough I’m calling Michael tomorrow ;D
Yeah, beer seems to be anti seize grease for secrets.
Yeah, beer seems to be anti seize grease for secrets.
Af has chosen the wrong barrels and twist rates. They are perfectly aware of it, and ignore it. And knew it before it was ever released. GRRRRR!!!
They had rather put their money into semi freak spokes persons rather than make a superior, or even so much as compentent products. Double GRRRRR!!!
Yeah, beer seems to be anti seize grease for secrets.
Never learned to like beer, now Crown royal and Coca-Cola, given enough crown, I will giveaway pretty much any secret.
I'm allergic to booze, I break out in handcuffs!
I have one bullet in particular that simply will not shoot well. It shotguns at any range, regardless of sizing changes.
Here it is at 50 yards. Three shots without what is being tested, and three using the center hole of the terrible group. Now, three + one, the one from the previous group and felt so good I sent two more down range for a total of 6 in there, for a clover leaf. Success! Repeated many times, 50 and 80 yards. Over and over again. all with bullets that until now, simply would not group.
More stoked than ever! Yep, blurry, couldn't see the screen on the camera in the direct light.
Can I guess? Is it a tuner like is used in .22lr BR??
I think so too! ;)
hmm.... did i miss something? Did i just scroll thru 5 pages and almost 2 weeks of the same thread and the "big reveal" is still a big secret?
Feel bad for the folks who have been following this thread for almost 2 weeks and are still completely in the dark...
Sorry, but it feels being teased. Not cool.
Sorry, but it feels being teased. Not cool.
[/
X2...If a fellow wants to explore commercial options, then by all means do so. But posting then witholding is teasing in my book as well.
Still...nothing worth any bunching of undies so no real excitement....just going to be some sort of harmonic damper. Lol
Al
So how does this perform for the 10-13ft lb crowd?
Some countries are limited to sub 12 ft lbs.
And some of us here in the USA use SPECIFIC ft lbs for indoor pest work where over penetration is NOT an option.
Yes it will. Infact, Hobbyman is on it as we speak. 8)Good to hear. 8)
I was not badgering, and was not trolling.
I just asked a question about would it help low power guns.
And I got squashed like a bug.
Thanks.
Oh, I agree on the shortcomings you listed for the Airforce platform.
And have been in place on my working gun for a few years.
My talon below clearing the rice mills 1 pest at a time.
(http://a64.tinypic.com/2d0z85t.jpg)
Off subject, hope the wife is recovering ok.
Thanks guy's. she is coming along well.
;)
Mike
While getting a bit of grief from a couple of members for not telling more and showing the device, I had to laugh to myself, as I had already posted a pic of the device almost by accident. I knew people would catch it. Oddly enough, no one noticed it. ;D
If it is not that noticeable on the gun, all the better. But once you see it, and know what it is, it is unmistakable. LOL! ;)
The first pic is the one I though members would catch it. Yes, blurry, just like ufo and bigfoot pics. Does it really exist, or is knife just making it up?
The pic of the HEB target dot is three shot without and was a well over 1" spread top to bottom. the group on the right is using one of the bullet holes as the target poa, and as you can see, it was a cluster. This was with the device. This has been repeated over an over by both myself and other testers. 8)
I see no reason why this device couldn't be fitted to slide fore and aft of a barrel for testing as well.
My apologies for it being so simple. but that is kinda the point. easy-Peasy.
It's simple, and it works.
One member ask, (Restern) if the results were simply due to the weight. I used a brass bar and cut it to match the weight and mounted it in the rings. Nope, No improvement what so ever. It isn't the weight.
I also tried the tried and true limb saver. It did help marginally, but it did not improve bullets that had issues, where the Anti variation device did.
These were dropped long ago in the Archery World as new methods came about. However, on ultra powerful high fps bows, seems for me, nothing worked batter. Yes, it adds weight, which for me only steadied the high stepping 3-D Bow all the more. Seems it does the same for our AG's. ;)
One of our members stumbled on two for sale, and got them in so didn't have to make his own. Worked for him as well.
Some of the testers were Dillon, Hobbyman, Travis, Darkcarsima, 3-D Ranch-OneShot, ScrewWork, I think, I wanted him on the list, but I forgot some. SantaClause. LOL, and a hand full of others. All gave good reports on results.
Should I post this on a new thread? PCP or Big Bore section?
I do want people to get the info.
Knife/Mike
While getting a bit of grief from a couple of members for not telling more and showing the device, I had to laugh to myself, as I had already posted a pic of the device almost by accident. I knew people would catch it. Oddly enough, no one noticed it. ;D
If it is not that noticeable on the gun, all the better. But once you see it, and know what it is, it is unmistakable. LOL! ;)
The first pic is the one I though members would catch it. Yes, blurry, just like ufo and bigfoot pics. Does it really exist, or is knife just making it up?
The pic of the HEB target dot is three shot without and was a well over 1" spread top to bottom. the group on the right is using one of the bullet holes as the target poa, and as you can see, it was a cluster. This was with the device. This has been repeated over an over by both myself and other testers. 8)
I see no reason why this device couldn't be fitted to slide fore and aft of a barrel for testing as well.
My apologies for it being so simple. but that is kinda the point. easy-Peasy.
It's simple, and it works.
One member ask, (Restern) if the results were simply due to the weight. I used a brass bar and cut it to match the weight and mounted it in the rings. Nope, No improvement what so ever. It isn't the weight.
I also tried the tried and true limb saver. It did help marginally, but it did not improve bullets that had issues, where the Anti vibration device did.
These were dropped long ago in the Archery World as new methods came about. However, on ultra powerful high fps bows, seems for me, nothing worked batter. Yes, it adds weight, which for me only steadied the high stepping 3-D Bow all the more. Seems it does the same for our AG's. ;)
One of our members stumbled on two for sale, and got them in so didn't have to make his own. Worked for him as well.
Some of the testers were Dillon, Hobbyman, Travis, Darkcarsima, 3-D Ranch-OneShot, ScrewWork, I think, I wanted him on the list, but I forgot some. SantaClause. LOL, and a hand full of others. All gave good reports on results.
Should I post this on a new thread? PCP or Big Bore section?
I do want people to get the info.
Knife/Mike
Hmmm, was I closest in the guessing thread?? :)
It maybe a similar approach to reducing harmonics in a crankshaft via a fluidampr harmonic balancer.
Suggestion:
Name your invention, and put it into a new thread. Give it a good start for the new comers of future years...
Mike's BAD device = Mike's Barrel Accurizer Dampener device
Matthias
Taso, I may very well be wrong, but I would think the end of the barrel is where the heaviest vibrations are. Even in my very heavily warped carbon sleeved barrel.
As far as inventions go, I'm not by any means the inventor. I just took an old idea, made for archery and tried it on a gun barrel. LOL!
In today's Green/politically correct world, I don't even know if the mercury dampers are still being manufactured.
After all, Mercury is known to the State of California blah-blah-blah.
Their opinions are not well respected in Texas. LOL
After all, Mercury is known to the State of California blah-blah-blah.
Thurmond, it took me a minute. Man, that cracked me up.
My mentor in the Knife World made a knife he carried for a lot of years. It was inscribed Bad Bob's. LOL
Kinda seems fitting. ;D
Suggestion:
Name your invention, and put it into a new thread. Give it a good start for the new comers of future years...
Mike's BAD device = Mike's Barrel Accurizer Dampener device
Matthias
Barrel Accurizer Damper Airgun Shot Stabilizer (I think you will get the acronym) ;D
I built a coaxial version of this that threads to the muzzle but I simply don't have any bad shooting bullets to try! :o
I also discovered that the CF Tubing I used is not impervious to oil permeation (it leaks through the CF)
Wow, Mike - that is almost an added pound hanging out there on the end of your barrel. I bet even if it were a solid mass, rather than the oil/shot dampener, that it could still have had a significant impact on the POI results.Actually a solid mass would not work anywhere near as well. It would also vibrate at the same frequency, or could perhaps set up a harmonic. The liquid-filled dampeners don't "move" as fast thus they break up the resonance.
I'm not sure I would want that much mass hanging out there on any rifle I would shoot offhand, but benchrest sure would be fine . . . .
Im taking it this wont work on a shrouded barrel? Dont see how it could.
Dampeners work excellent for high speed skiing, so this makes good sense.
So- since we now have it on good authority that these BAD devices work on PCPs,
now one needs to be added to a springer- especially a lightweight twangy springer like my B-3.
PeterI'm game, Don, but I'm gonna be back on the road shortly for a couple weeks, so I may not be the best choice unless folks are willing to wait for results.
I have a spare C&H Mercury recoil dampener, it is a 11 oz stock model, 7/8" x 4" long and a spare mount,
if you would like to try it, the only costs would be shipping to and from you/me.
Drop me a PM if you are interested etc.
http://www.mercuryrecoil.com/suppressors/index.htm#top (http://www.mercuryrecoil.com/suppressors/index.htm#top)
Tia,
DonDampeners work excellent for high speed skiing, so this makes good sense.
So- since we now have it on good authority that these BAD devices work on PCPs,
now one needs to be added to aa springer- especially a lightweight twangy springer like my B-3.
Suggestion:
Name your invention, and put it into a new thread. Give it a good start for the new comers of future years...
Mike's BAD device = Mike's Barrel Accurizer Dampener device
Matthias
Barrel Accurizer Damper Airgun Shot Stabilizer (I think you will get the acronym) ;D
I built a coaxial version of this that threads to the muzzle but I simply don't have any bad shooting bullets to try! :o
I also discovered that the CF Tubing I used is not impervious to oil permeation (it leaks through the CF)
Thurmond,
What about silicone oil or possible thicker silicone grease?
I am also curious if there is enough movement and impacts of the lead shot to break up into small pieces? I doubt it since lead is so malleable. There's also Hevi-shot that's denser and non toxic.
Taso
I have been looking at the viscosity of various fluids and came up with the following approximate values at room temp....
Water.... 1
Mercury.... 1.5
Ethylene Glycol.... 18 (anti-freeze)
Hydraulic Oil ISO 15.... 35 (many ISO Grades are available)
Automatic Transmission Fluid.... 70
10W Motor Oil.... 140
30W Motor Oil.... 280
I doubt you would want anything thicker than that.... JMO....
Bob
Well now. The dead blow hammer now has no oil compared to the original dead blow hammer. And it works as it should. knife said this device spring off of that of a dead blow hammer.I think we need some assemblies made in clear tubing and recorded with a high speed camera. I'll bet the fluids, especially the Mercury do some neat things!!!
I think oil needs to be thin in viscosity for the shots to move freely just as fast as the force it opposes to make it effective in dampening/canceling out the negative hamornic vibration or jump. The deadblow hammers now doesn't have fluilds and works with only half of cavity filled. Same concept could be applied here Right???
I particularly like the idea of hiding vials of Mercury inside an LDC.... They would have to be strong enough to never leak, and mounted securely enough to do the job.... but it should work.... It is almost twice as dense as lead shot, so 1 CI would weigh nearly 8 oz.... Since it is a liquid, you would not need as big a gap between the walls of concentric cylinders, which would make such an arrangement slimmer than with lead shot....Thank you for spelling that out. That is exactly what my though process was.
Bob
Mercury can form an amalgam with aluminum, lead or gold, and can combine with copper (the main component of brass).... Generally the oxide coating on any metal will prevent a reaction, but if the metal is scratched through the oxide layer, then the mercury will combine with it in some way.... As kids, we used to coat copper pennies with Mercury, and they looked like a shiny dime (hey, I'm still alive).... ::) …. However, it is relatively unreactive with steel.... I don't know about brass, it may well depend on the alloy....I guess more specifically, if a thinwall brass "vial" containing mercury is between an aluminum shroud and a steel barrel might there be any issues?!
Bob
Mercury can form an amalgam with aluminum, lead or gold, and can combine with copper (the main component of brass).... Generally the oxide coating on any metal will prevent a reaction, but if the metal is scratched through the oxide layer, then the mercury will combine with it in some way.... As kids, we used to coat copper pennies with Mercury, and they looked like a shiny dime (hey, I'm still alive).... ::) …. However, it is relatively unreactive with steel.... I don't know about brass, it may well depend on the alloy....
Tim, I think the shot has to be able to move relative to itself, in reaction to barrel vibrations.... What you are suggesting might work better to reduce recoil, IMO.... I think the fluid is mostly to prevent the shot from rattling and to protect it from beating itself to dust.... I plan to try a 10 weight oil, at least in the first one.... I want to get some synthetic 10W 2-stroke oil to try Knife's bullet lubing, so I'm just going to use that....
Bob
I got a few shots in before the rain started. Five shots without device and five shots with the device at 50 yards.
I need to shoot more groups to verify if these results hold up.
Weight of device is 2.8 oz which caused the drop in impact point but left ,right stayed the same. My rifle is set up for 25fpe.
Robert R
Great results, cleaner group for after target. 8)
Would you care to add more info on what type of filler/oil and shot used,
dimensions of your device, weights of stock material etc?
Is there a possibility of adding a fill spot to add or remove the inside components,
to change the total spec's of your dampener?
Thank you,
DonI got a few shots in before the rain started. Five shots without device and five shots with the device at 50 yards.
I need to shoot more groups to verify if these results hold up.
Weight of device is 2.8 oz which caused the drop in impact point but left ,right stayed the same. My rifle is set up for 25fpe.
I got a few shots in before the rain started. Five shots without device and five shots with the device at 50 yards.
I need to shoot more groups to verify if these results hold up.
Weight of device is 2.8 oz which caused the drop in impact point but left ,right stayed the same. My rifle is set up for 25fpe.
Not trying to rain on your parade — actually I'm really excited I get to witness innovation and the progress of our hobby as it happens!I don't have a bullpup... yet!
So, here comes my question when looking at the photos of the MAD Pipe*:
Would this work on bullpups where the airtube extends right up to the end of the barrel? :-[
*MAD Pipe = Mike's Airgun Dampener Pipe
Matthias
Just threw this snake oil contraption together. Going to zip tie it to the .25 mrod and shoot the 43gr bbt it absolutely hates. Licky if its 3” at 20yds.
4 2/34” shells of 8 shot with propylene glycol.
Just threw this snake oil contraption together. Going to zip tie it to the .25 mrod and shoot the 43gr bbt it absolutely hates. Licky if its 3” at 20yds.
4 2/34” shells of 8 shot with propylene glycol.
Now that would be cool to capture in slow motion! We would be able to see what's going on with your clear container and liquid Tim! ;D
Taso
Thank You Sir!Dang Knife! Watch the typos! (grin)
I'm rather excited to see Robert suing bb's, and it worked for him. I didn't think it would be enough weight. May very well be the ticket for low power/medium pellet shooting! ;)
Knife
Guys,Add barrel placement to that list, although I am sure a pic would provide similar info, in these "testing" stages, measurements of barrel/shroud length and placement of the device *may* prove to be crucial. Then again... maybe not. But the testing has to be done first to determine that, one way or another.
With Knife's blessing, ;)
Here is some info that would be greatly appreciated and should be followed about your device you have built,
if there is anything info/spec's missing on the below form, just add a line for it etc.
Design Form Spec Sheet of each build and the builder fills out,
Name:
Gun/caliber:
Pellet/slug/bullet weight/FPE/FPS range:
Total overall length and weight of device, including mounting system:
Tube diameter/material:
Amount of weight used/BB size:
Amount of Oil/Mercury used:
Attachment clamp:
Photo's of device/targets etc:
Comments on using:
Tia,
Don
Sorry, I was put on mussel relaxers after injury to back. (surgery two years ago). Was finally getting over and hurt it somehow.Yeah, now we know the REAL reason for the improvements in accuracy! LOL!
I don't do well on med's. Makes me loopy as a goose! :(
Way to go Don!
Yep, placement location, and whether lead shot or steel bb's. would be helpful as well.
Man, I had to correct the heck out of this short reply. GRRRR!!!
Thanks Kerry!
Design Form Spec Sheet of each build and the builder fills out,Thanks Don!
Name: Nvreloader
Gun/caliber: Gauntlet/22 caliber
Pellet/slug/bullet weight/FPE/FPS range: 14.3 Crosman HP pellet/25 FPE - 900 FPS
Total overall length and weight of device, including mounting system:
4" long x .625" dia = 2797.5 grs = 181.27 grams= 6.40 oz
Attachment/clamp weight: Shotgun mag tube clamp = 464.9 grs = 30.12 grams
Tube diameter/material: Steel (OEM) C&H Recoil Suppressor
Amount of weight used/BB size: N/A
Amount of Oil/Mercury used: Mercury
Photo's of device/targets etc: Pending
Placement of device: Clamped under the shroud, Right under the air stripper that's inside the shroud,
22" from breach face
Comments on using: Tightens the group, less flyers, @ 40 yds, more testing ongoing
This is my version of Knife's discovery. I am going outside to test, storm clouds rolling in.
Just threw this snake oil contraption together. Going to zip tie it to the .25 mrod and shoot the 43gr bbt it absolutely hates. Licky if its 3” at 20yds.
4 2 3/4” shells of 8 shot with propylene glycol.
Kirby I was testing some more yesterday , it was a little breezy but found it works best by the muzzle as in the pic. I am also going to adjust internals to see if there is a difference.
Toughest thing is to find conditions the same so the test will be more accurate.
Mike, by "stiff enough" I meant "crowbar stiff".... like a 1" or larger diameter bull barrel.... I have some barrels here that have 20mm OD CF sleeves on them, and while they are "stiff" I would still expect to see some effect with the damper.... What I was trying to convey is that the more limber the barrel, the more likely it is to have a larger effect.... JMO, having never used one yet....
Bob
Tim , might I suggest you put more shot in your device .
ThankYou Charles.
it seems more and more people are finding success with these. I had no hope of it working with pellets. Wasn't even on my radar. I'm very happy to be wrong. 8)
Thank you for sharing. Maybe I just got lucky, don't think so. I think you have hit on something transformative for airguns, and Donny missed the boat. Time will tell.
Knife, just hold on to the mold for another month or so. Let's hit a 6 month mark since when I sent you that mold. 😝. Send it back when you have made 10000 slugs from it. Haha
I would also like to test the new slugs from it since the ones I casted were indeed lobesided. And the device is being made as we speak. Too man projects too little time
Knife, just hold on to the mold for another month or so. Let's hit a 6 month mark since when I sent you that mold. 😝. Send it back when you have made 10000 slugs from it. Haha
I would also like to test the new slugs from it since the ones I casted were indeed lobesided. And the device is being made as we speak. Too man projects too little time
I know what you mean Duy. Todays, (last nights) was converting the hammer system in the RS to the FX system With the guide in the hammer which added 4.85 grams and adding a smaller spring inside the hammer spring to ride on the guide. Picked up another 25+ fps. It is working well. WooH00!!! I think it will allow me to lower the reg pressure in order to get better shot count. That, and I really don't need the high fpe for pest birds and vermin. The hp's open so violently, that it just isn't necessary. (Insert Devil Horns Here)!
I haven't touched the mold since getting here true again. I need to cast some, and test while sending you a batch. I've been so engrossed in the HP's I'm tinkering with.
Man, they are destructive. Took out a cow bird this morning when leaving the shop. Blew the sucker completely in half. Not much left for the foxes. LOL!
I can send some of those too. But you probably don't want to get to liking them. I have over 400 bucks in the mold. Grrrr!!! + Ouch!
Un, mercury filled wrist weights? If they work, I NEED Them! Old age sux! :(As Bette Davis said "Getting old ain't for sissies!".
Beats the alternative though. ;D
I tested my three HPA Varmint rifles today, as is, then with the light (4 oz.) damper and then with the heavy (8 oz.) damper.... All three are regulated, shooting pellets at about 960 fps.... The results were mixed.... I tested at 50 yards, shooting from a bench with BiPod and rear bag, using each guns preferred pellet (JSB), and one other pellet, just for comparison.... These three rifles have been used for 3 or more years and have never been cleaned, so the first test of each was to shoot one mag. "from cold", then clean with 4 passes of a bore snake (brush removed)…. I shot two full mags. for each test, which means 7 shots in .30 cal, 8 shots in .25 cal, and 10 shots in .22 cal.... When I had completed the 50 yd. testing with each gun I moved out to 100 yards, to see if I could find any difference using the damper.... Groups are all measured C-T-C....
My .30 cal "Bobcat" uses 45.8 gr. JSB Exacts.... The first two shots were 2" and then 1" low, and the next 5 in a nice group.... After cleaning the 7 shot group was only fractionally larger, and shot to the same POI, so the cleaning (after 3+ years of shooting) did NOTHING !!!.... The two groups after cleaning but without damper were 11/16" and 3/4".... Using the light damper the two groups were 11/16" and 7/8".... Using the heavy damper, they were 5/8" and 15/16".... The smallest group was using the heavy damper, but the most consistent groups were with no damper.... The heavy damper shot to the same POI as with no damper, but the light damper hits about 1/2" lower at 50 yards.... When I tested at 100 yards, I could not draw any firm conclusions as to the effectiveness of the damper.... The POI stayed about the same, and the group size was more affected by conditions and how well I shot.... Honestly, there was so little difference with or without the damper at 50 yards, any difference just got "lost in the noise" at 100 yards....
Next up was my 2560 HPA, again regulated, shooting 25.4 gr. JSB Kings at about 960 fps.... Before cleaning the group at 50 yards was 7/8", and after there were two "fliers" before the gun settled down, producing a group of 9/16" and 7/8".... Other than the two fliers right after cleaning there was no noticeable change after using 4 passes of the bore snake.... The groups with the light damper were 1/2" and 15/16", about 1/4" lower on the target.... With the heavy damper, the groups were 1/2" and 1-1/4", about 1/2" lower at 50 yards.... Once again, the dampers produced a fractionally tighter "best" group, but the poorer group was larger than without any damper.... I tried some of the 26.7 gr. NOE Hunter pellets, and for a full mag. of 8 shots, with the light damper got a group of 1-3/8" but that dropped to 1-3/16" when I removed it.... When I tested the JSBs at 100 yards, I actually got slightly tighter groups without the damper, but not by much, maybe 1/4".... Once again, the other accuracy factors at 100 yards swamped any real difference with or without the dampers....
The last gun I tested was my 2260 HPA, also regulated, shooting 18.1 gr. JSB Heavies at about 960 fps....From cold, the first two shots were 1-1/2" and then 3/4" low, and then the other 8 went into 3/4".... After cleaning there were no fliers, no change in POI, but I put all 10 into 7/16".... so in this case the bore snake appears to have helped a bit.... With the light damper I put 8 into 9/16" with 2 fliers that opened the group to 1", and with the heavy damper I had a similar result, 9 into 11/16" and a flier that made it a 1" group.... Other than that flyer, the POI with the heavy damper was the same as without any damper, but the light damper shot about 1/2" lower at 50 yards.... I tried some of the 19.7 gr. NOE Hunters, and could not see any significant difference with or without either damper.... At 100 yards, this gun grouped tighter without the damper, with fewer fliers....
I attached the dampers to the bottom of my barrel immediately behind the air stripper.... I used two cable ties with the heavy damper, and just one with the light damper, pulled up really tight.... You could rotate the damper left and right but it took significant force to do that, and the dampers never moved during any of the shooting sessions with any of the three guns.... The .30 cal has a CF sleeved barrel that is 0.59" OD.... The .22 and .25 cal guns both have a 3/4" shroud over the barrel, and the air stripped is tightened slightly more than hand tight to tension the barrel.... The dampers on those guns was, of course, attached under the shroud, which is a snug fit over the back of the air stripper....
I feel that this was a fair test of the dampers on three different calibers of relative high powered pellet shooters.... The .22 is 37 FPE, the .25 is 52 FPE and the .30 cal is 94 FPE.... They were shooting their best ammo, and all three can shoot MOA at 50 yards on a good day, and 1.5-2 MOA at 100 yards when I am on my game and the wind cooperates.... I actually shot my best ever group today at 100 yards, just missing qualifying as a NUAH Master by 1/16" (all 5 in the 10 or X, 1.06" C-T-C, with the .30 cal)…. You can see the target in this months 100 yd. match....
https://www.gatewaytoairguns.org/GTA/index.php?topic=158928.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=158928.0)
I can see where you could get fooled by only shooting one group either with or without the damper, into thinking it does, or does not, work.... My conclusions from today are that there IS a difference in the weight of shot used, and it seems that a more powerful PCP may benefit from more shot weight.... The best groups in both .25 and .30 cal were shot with the heavy dampers, but only by about 1/16", and I didn't get an equally small second group to confirm the supremacy of the damper.... My .22 cal actually shot a bit better without any damper....
So there you go, take it for what it's worth.... one guy, on one day, shooting 3 guns, without damper, with 4 oz. of shot and with 8 oz. of shot.... I was starting with PCPs that already shoot very well, so perhaps not the ideal way to find an improvement....
Bob
I don't think having a damper that weighs the same as the pellet will work at all.... not even close to enough weight.... My light damper had 1750 grains of lead shot, and the heavy one 3500 gr.... ie 70 to 100 times the pellet weight.... Additionally, the stiffer the barrel, the less effect I think a given damper weight will have....That is sort of what I was thinking. It is harmonic vibration that is being dampened, not the energy/weight of the pellet. At least, that's what I am thinking.
Bob
So, just out of curiosityI don't think you are off, but I think that has been discussed earlier in this thread. I don't remember what the consensus was from the folks who are designing/building/testing the MAD.
you could make an LDC with an extra outside chamber ( all around the unit ) as a damper right ?
it would be a bit thicker looking LDC but it wouldn't look as bad as would an extra device hunging from the barrel/shroud,
How off am I ?
If you are going to try a concentric arrangement, I would want to see the annular gap between the tubes more than twice the diameter of the shot.... Otherwise I think the shot could "jam" instead of being free to move up around the sides of the inner tube.... That means the ID of the outer tube has to be about 0.400-0.420" larger than the OD of the inner tube to provide that gap.... In other words, if you are putting this around the outside of an LDC, you are going to need to increase the diameter by about 1/2".... ie more than just "a little".... JMO....
Bob
Be interesting to see if this concept works when designed to surround the entire barrel or if it works because it's on one side of the barrel.
If you are going to try a concentric arrangement, I would want to see the annular gap between the tubes more than twice the diameter of the shot.... Otherwise I think the shot could "jam" instead of being free to move up around the sides of the inner tube.... That means the ID of the outer tube has to be about 0.400-0.420" larger than the OD of the inner tube to provide that gap.... In other words, if you are putting this around the outside of an LDC, you are going to need to increase the diameter by about 1/2".... ie more than just "a little".... JMO....
Bob
The concentric designs I offered earlier, which fit over the barrel instead of over the LDC, could be made about the same OD as the LDC, or even smaller.... The problem comes if you have an air reservoir extending right to, or near to, the muzzle.... As an example, on a bottle gun, you could have a combination damper and LDC where the rear damper portion slides over the barrel OD, and the part in front of the muzzle was just LDC.... It could likely all be built into the same OD tube.... something like this....
(https://i378.photobucket.com/albums/oo221/rsterne/Parts%20for%20Sale/Coaxial%20Damper%20and%20LDC_zpsnedoapjl.jpg) (http://s378.photobucket.com/user/rsterne/media/Parts%20for%20Sale/Coaxial%20Damper%20and%20LDC_zpsnedoapjl.jpg.html)
Great minds think alike, Manny.... 8)
Bob
If you are going to try a concentric arrangement, I would want to see the annular gap between the tubes more than twice the diameter of the shot.... Otherwise I think the shot could "jam" instead of being free to move up around the sides of the inner tube.... That means the ID of the outer tube has to be about 0.400-0.420" larger than the OD of the inner tube to provide that gap.... In other words, if you are putting this around the outside of an LDC, you are going to need to increase the diameter by about 1/2".... ie more than just "a little".... JMO....
Bob
If you are going to try a concentric arrangement, I would want to see the annular gap between the tubes more than twice the diameter of the shot.... Otherwise I think the shot could "jam" instead of being free to move up around the sides of the inner tube.... That means the ID of the outer tube has to be about 0.400-0.420" larger than the OD of the inner tube to provide that gap.... In other words, if you are putting this around the outside of an LDC, you are going to need to increase the diameter by about 1/2".... ie more than just "a little".... JMO....
Bob
Not to mention, would the heavy shot not STILL end up BELOW the barrel anyway? Just thinking out loud... ::) ???
And that gets me thinking that if you have the barrel pointed UP long enough before you shoot, then the shot/weight would be at the back (chamber end) of the MAD. If the viscosity of the oil/liquid was too high, then the shot might not be able to do the dampening job as intended?
I mean, if the shot is at one end of the device, then it can ONLY react in one direction. Right? So, is it the weight or the movement of the weight making the difference?
OK... I'll just shut up now and listen. ;D :D
If you are going to try a concentric arrangement, I would want to see the annular gap between the tubes more than twice the diameter of the shot.... Otherwise I think the shot could "jam" instead of being free to move up around the sides of the inner tube.... That means the ID of the outer tube has to be about 0.400-0.420" larger than the OD of the inner tube to provide that gap.... In other words, if you are putting this around the outside of an LDC, you are going to need to increase the diameter by about 1/2".... ie more than just "a little".... JMO....
Bob
Not to mention, would the heavy shot not STILL end up BELOW the barrel anyway? Just thinking out loud... ::) ???
And that gets me thinking that if you have the barrel pointed UP long enough before you shoot, then the shot/weight would be at the back (chamber end) of the MAD. If the viscosity of the oil/liquid was too high, then the shot might not be able to do the dampening job as intended?
I mean, if the shot is at one end of the device, then it can ONLY react in one direction. Right? So, is it the weight or the movement of the weight making the difference?
OK... I'll just shut up now and listen. ;D :D
Then, you can attach the weight to a spring.. Make sense..
Has anyone made one with lead shot and maple syrup?
Asking for a friend. ;D
Yes, but the the majority of the MAD devices being made are using lead shot (mercury in some) and oil or some other viscous liquid, not a solid weight. And the spring may introduce more harmonics to the equation.
But lead could be molded onto the middle of the spring and make the ole spring float in the viscosity desired but will return to it's initial place in the reservoir..
Yes, but the the majority of the MAD devices being made are using lead shot (mercury in some) and oil or some other viscous liquid, not a solid weight. And the spring may introduce more harmonics to the equation.QuoteBut lead could be molded onto the middle of the spring and make the ole spring float in the viscosity desired but will return to it's initial place in the reservoir..
::) more people with their brain might come to a near solution.
Now THAT I did not think of. Putting the weighted spring into the viscous fluid!
It might work!
Dang.... I think I just got eliminated from the conversation.
Yes, but the the majority of the MAD devices being made are using lead shot (mercury in some) and oil or some other viscous liquid, not a solid weight. And the spring may introduce more harmonics to the equation.QuoteBut lead could be molded onto the middle of the spring and make the ole spring float in the viscosity desired but will return to it's initial place in the reservoir..
::) more people with their brain might come to a near solution.
Now THAT I did not think of. Putting the weighted spring into the viscous fluid!
It might work!
More brains to solved the puzzle might be a good thing. ::)
yep maple syrup great on penut butter, banana sandwiches...
some barrels will be low amplitude High frequency others can be higher amplitude lower frequency... and shades in between... so one size fits all will definably not work...
wonder if a xylophone mallet would get a mounted freq that could be recorded and analyzed with audacity or similar... then just might have a clue about which freq it is resonant (reacts most)at... then design the damper to be most effective for/near those freqs..
::)
So, just out of curiosity
you could make an LDC with an extra outside chamber ( all around the unit ) as a damper right ?
it would be a bit thicker looking LDC but it wouldn't look as bad as would an extra device hunging from the barrel/shroud,
How off am I ?
yep maple syrup great on penut butter, banana sandwiches...
some barrels will be low amplitude High frequency others can be higher amplitude lower frequency... and shades in between... so one size fits all will definably not work...
wonder if a xylophone mallet would get a mounted freq that could be recorded and analyzed with audacity or similar... then just might have a clue about which freq it is resonant (reacts most)at... then design the damper to be most effective for/near those freqs..
::)
Let me explain my thinking of the mechanical effect... Take as an example the swinging pendulum.. The two extreme are equal weight and they react to each other with EQUAL FORCE.. During this time, the middle weights are stabilize.. So!! I consider the projectile and the weight inside the device to be the 2 extremes of the pendulum.. The barel would be the stabilize weight in between the two..
IMO using a fluid with a low density, instead of lead shot (with or without fluid) as the dampening medium, just requires a much larger device.... Let's say you use oil with a density of 1, instead of lead shot with a density of 7.... You would need 7 times the volume to get the same mass and effect.... If you use mercury instead of lead, you could use about half the volume.... The higher the viscosity, the less the fluid will move in a sort time frame, which a shot certainly is.... With lead shot, and the damper 3/4 full, you give it a shake and it sloshes around, ie it ACTS like a fluid.... Take the same weight of lead in a cast block, not so much.... Put that mass inside the same damper, with a spring both ends, yep it will rattle around, but with different properties than a fluid, that's for sure.... Mount that lead block solidly to the barrel and you will get yet another effect.... Some guns may prefer one over the other, and my guess is that every device you can build may benefit from sliding it fore and aft on the barrel to tune it for each pellet/bullet and velocity.... We do that with mass dampers (and limbsavers) today....
Mike's "discovery" was that making a damper partially full of lead shot (and oil) to create a dense, moving "fluid" inside it.... and then clamping it near the muzzle (actually beyond it, in his original tests, it was on the LDC)…. reduced the group size with all but one bullet he tried, in relatively high powered PCPs.... He never thought it would work with pellets or low powered PCPs but in some cases it seems to (and some it doesn't).... IMO using a solid mass mounted on springs, or a pendulum, or a glob of peanut butter that must be reapplied precisely after every shot.... is dragging the original idea soooooooooooo far off course we are just getting deeper into the woods without a compass, or even a trail of breadcrumbs to follow.... It is not my intention to discourage innovation and development, far from it.... but realistically if you have an idea to try, get out and try it, instead of suggesting something you haven't tried.... JMO....
Bob
Alain. I don't think matching the pellet weight is a good idea. You have to be able to see that...the whole front barrel moves, not just the pellet. So matching the pellet in weight will be inefficient. If you have to counter the whip of the barrel...at least use half of the barrels weight. Of course I have no mathematical equations to back this up but I think it Dallas into the common sense bracket. And from there just a bunch of trail and errors.
I am beginning to think the reason our airguns shoot better once we find the upper limit, and then turn then down a bit, is that vibration Kinfemaker has revealed to us.
Roachcreek
...using a solid mass mounted on springs, or a pendulum, or a glob of peanut butter that must be reapplied precisely after every shot.... is dragging the original idea soooooooooooo far off course we are just getting deeper into the woods without a compass, or even a trail of breadcrumbs to follow.... It is not my intention to discourage innovation and development, far from it.... but realistically if you have an idea to try, get out and try it, instead of suggesting something you haven't tried.... JMO....
Bob
I am having fine results with many different bullet. Pellets as well now.I know you are going to start to working on what I asked about.
Now if I could just figure out the twist I need, i would be set.
I need to write Mr. Bob. .
I need to make a smaller and lighter version and test. Testing different ideas is what I enjoy.
I very much appreciate so many here jumping in and testing different takes on the concept. It indeed does have the possibility of being a game changer for those of us who are accuracy nuts.
More shop time tonight on another idea. LOL ;) 8)
Knife/Mike
I am having fine results with many different bullet. Pellets as well now.I know you are going to start to working on what I asked about.
Now if I could just figure out the twist I need, i would be set.
I need to write Mr. Bob. .
I need to make a smaller and lighter version and test. Testing different ideas is what I enjoy.
I very much appreciate so many here jumping in and testing different takes on the concept. It indeed does have the possibility of being a game changer for those of us who are accuracy nuts.
More shop time tonight on another idea. LOL ;) 8)
Knife/Mike
A device that calms my shaky hands! (chuckle) ;D
I am having fine results with many different bullet. Pellets as well now.I know you are going to start to working on what I asked about.
Now if I could just figure out the twist I need, i would be set.
I need to write Mr. Bob. .
I need to make a smaller and lighter version and test. Testing different ideas is what I enjoy.
I very much appreciate so many here jumping in and testing different takes on the concept. It indeed does have the possibility of being a game changer for those of us who are accuracy nuts.
More shop time tonight on another idea. LOL ;) 8)
Knife/Mike
A device that calms my shaky hands! (chuckle) ;D
OK, may release lead shot filled weighted gloves. There ya go! ;D ;)
Guys!! After my last session of shooting yesterday, I unmounted my device and analyze if it was a flaw in design.. Nothing is wrong with it.. But by playing with it on the barel, I think I may have find another path where it may apply.. My conception is leaning towards RECOIL MANAGEMENT in big bore application. What we are chasing for is eliminating the whiplash of the barrel or having a CONTROLLED HARMONIC with the barrel.. The yaw and pitch is what make the projectile unpredictable... Before I go all in with my discovery, I want to ask other thinkers and experience members what is their take on it... It could attach to a barrel weight or a LCD as an ANCRE POINT.... The slip over sleeve is empty and we could use the opposite end of the sleeve and glue a ruber washer that would slip over the barrel to control the lateral and vertical movement.. The sleeve could be slide in and out for controlling different harmonics and power levels... The only CRITICAL component in this build is the quality of rubber used.. Too hard the type of rubber, harsher could be the harmonic.. Too soft could lead to no control at all.. For now I have 2 type of rubber I want to use... The rubber mat I use at my work bench is cushy and return to it's original form pretty quickly.. The other type was recoup from a job site and was red and they were placing it between the creat and the electronic box but it is just a bit harder. Let me know your taught..
Kerry!! What I am saying is, WE might have looking at the wrong direction.. If you look at all the devices used, they ALL ACT AS THE MERCURY TUBES they use the burry in the butt stock in the 80's for better recoil management because it interact in the same AXIS AS THE BORE... We are chasing the harmonics that occurred at 90* of the axis..
All the SLUSH MECHANICAL DEVICES are active in the same axis of the bore but due to their added weight, they might act as a vertical damper....
The amplitudes of the harmonic are manageable with a BUMPER like the rubber washer that hold the desired weight to counters the amplitude to a minimum level..
Knife, I’m all in. Like some, I was somewhat skeptical at first, but not now. I had to try your discovery for myself, and was blown away. Wow!
We are having almost constant rain, so I set an ironing board (best I could come up with) on my front porch with a heavy sand bag on top as a bench. Set out a target at 50 yds. Shot several 5 shot groups with my .22 FX Dreamlite. The heavy bag helped steady things up. Still it took several groups for me to settle in. From the picture, the three bottom groups I shot without your discovery. I do general do better, usually about .4”-.5” but as I said it took a while to get settled in. The top two groups I shot with my version of your discovery, I came up with #1 .275” center to center; POI shifted quite a bit low right. #2 I gave a few clicks up and left same POA .245” center to center. That is the best groups I have ever shot with anything! Amazing! I ran out of time but will certainly be doing more experimenting. Can't wait to see what becomes available.
Specs as follows: The stabilizer I used is from my @=S+S%^$# days in the 1990s, and is oil (?) filled. It did a good job, with an extension of taming a short little Mathews hunting bow I had. No markings on it, so brand or model is a mystery.
1” dia. steel tube with aluminum end caps
3 3/16” Long
3.2oz wt.
The bracket I made from a steel bar. I drilled and tapped it 1/2”x20 to fit my Dreamlite barrel threads. I put an o-ring on barrel threads before screwing on and snugging up on the barrel. I drilled the bar 1/4” and used a 1/4” screw to mount the stabilizer on the bar.
4.8 oz. Total wt. for mount and stabilizer
.22 FX Dreamlite
18.13 gr. JSBs straight out of tin
900 fps
Light rain falling 0 wind
Sorry, I don't understand the "nowhere to go laterally" bit.... Since the lead shot only fills the tube 3/4 full, it can move in any direction except down, as gravity is already holding it down inside the damper.... However, should the barrel initially kick "upwards", it would accelerate the shot up, but the shot, from it's own momentum would not follow the barrel down immediately.... You have to remember, the movements we are trying to damp out are tiny.... A 1" change at 50 yards (150 ft. = 1800 in.) would only be 1/900" in a 2 foot barrel (just over 0.001")….
I don't know how well a weight mounted in rubber would be in acting as a harmonic damper, but I would think it would be similar to a "limbsaver", which is a rubber weight you slide along the barrel until you get your smallest group.... All I can suggest is to build it and see what happens....
Bob
That’s a nice lightweight bullet . It must be pretty short at that weight , less than .4?
these powders are likely to be rough particles that might bind and pack
those okie cushins look ridged , the newer Hy tecs have a flexiable core with a (powder) weighted end, they attach at one end only, allowing the weighed end to act and react to the initial vibration with a slight delay to counter the first movement
my Hi Tec should be here Friday from flea bay, got to go see my friend who owns his welding shop to source a piece of steel to fab my mounting bracket(clamp)
then we are off to the race to calm my P-15 down. it has a 23" LW barrel shooting 25 gr(25 cal) at 970 fps. groups are a little bigger than they should be at 50 yd
I believe the end of the barrel is flickering multiple times in a not exactly repeating the same pattern with each shot, more fractal in nature
our targets show the non repeating results
ADDING A TUNER.... Adding a tuner to the muzzle of a rifle barrel does the following:
1. The additional mass reduces the amplitude of the vibrations.
2. Decreases the natural frequencies by decreasing the lower Mode's frequencies more than the higher Modes.
3. Increases the barrel's vertical end sag due to the extra weight. This would tend to make the vertical plane the preferred plane of vibration.
4. Moves the Mode 2 node closer to the muzzle.
For those of you who haven't seen this website, I suggest you have a look, it explains a lot about barrel vibration modes, and the frequencies involved.... Mode 1 and Mode 2 are the predominant modes of vibration....
http://www.varmintal.com/atune.htm (http://www.varmintal.com/atune.htm)
If the bullet/pellet was arriving at exactly the same time during the vibration mode, then it would shoot to the same POI.... Here is Varmint Al's summary of what the addition of a tuner does....QuoteADDING A TUNER.... Adding a tuner to the muzzle of a rifle barrel does the following:
1. The additional mass reduces the amplitude of the vibrations.
2. Decreases the natural frequencies by decreasing the lower Mode's frequencies more than the higher Modes.
3. Increases the barrel's vertical end sag due to the extra weight. This would tend to make the vertical plane the preferred plane of vibration.
4. Moves the Mode 2 node closer to the muzzle.
He then talks about what happens when you move the position of the tuner.... This should apply to any "solid" mass rigidly fixed to the barrel.... How a dense fluid tuner varies is only speculation at this point, IMO....
Bob
Perhaps I am misunderstanding what you are trying to build.... but sliding a weight along the barrel is basically trying to change the harmonics so that the pellet arrives at the muzzle when it is pointing in a consistent direction.... In other words, you are tuning the barrel for a specific pellet and velocity, exactly what the rimfire benchrest shooters do.... This harmonic tuner I made does the same thing....the vibration cycles are very short in lenght and it takes a fine threaded tuner like this one of Bob's to center it in just the right spot
(https://i378.photobucket.com/albums/oo221/rsterne/6mm%20Sporter/Harmonic%20Tuner_zpsejrausfr.jpg) (http://s378.photobucket.com/user/rsterne/media/6mm%20Sporter/Harmonic%20Tuner_zpsejrausfr.jpg.html)
The threaded steel sleeve is screwed onto the barrel and tightened in place.... The brass weight moves back and forth to tune the vibration of the barrel to your pellet and velocity.... It is 28 TPI, so it only moves 0.003" for each "hour" (30 deg.) you turn it.... I have not had the opportunity to do much testing, but I understand movements as small as 0.002-0.010" can make a big difference in group size, depending on the weight you are moving back and forth....
The difference between moving a solid weight and using a mass of "lead slush" (or mercury) is that I think the latter would have a wider "sweet spot", and be less critical on placement.... The reason I suggest that, is that if with one pellet and velocity the barrel is not moving much, the damper effect would be small.... However, with another pellet and velocity, that is not shooting well because the barrel is whipping around, the damper should have more effect.... That, logically, to me would be why it seems to work better on improving "poor" bullets or pellets.... The moving shot "damps" the vibration, rather than "tuning" it to a given frequency like moving a solid weight does.... JMO....
I have been giving more thought to the viscosity of the oil in the damper, and I think the "thinner" it is, the better.... We are dealing with a very short duration event here, the pellet is only in the barrel for about 3 mSec (0.003 sec.)…. At 850 fps, it travels the last 2" of the barrel in just 0.2 mSec.… As viscosity increases, the fluid takes longer to move for a given force applied to it.... Think about dropping a single #8 shot onto grease, heavy gear oil, light hydraulic fluid, or water.... It might take days for it to make a dent in the grease, a minute or more to drop an inch through the heavy gear oil, a second or two through the light hydraulic fluid, and almost no delay through the water, even though the water is more dense (ie oil or grease float on water)….
Mercury is probably the ideal fluid, because it is nearly twice as dense as lead shot (13.6 vs. 7.0), so the same weight takes up half the volume.... In addition, it's viscosity is only 1.5 (water being 1.0), whereas a light hydraulic oil (like the power steering fluid I used) is about 80, and 30W motor oil is about 350.... Simply put, for a given force applied, the lighter the oil, the faster the lead shot can respond to the barrel vibration.... and it doesn't have long to respond during the 0.0002 sec. it can affect the flight of the pellet.... Mercury can respond even faster....
Bob
Taso
That is the same thing I found,
"A patented POWDER Compound", is several devices I found on line etc.
No reference to what type of powder compound, so far. ;)
If the patent # is given, and you could find the info in the patent office,
it might list what type of powder is used inside etc.
Tia,
Don
;) both methods will work
Bob uses a static weight adjusted to the highest node of the vibratory cycle
Grand-galop's pendulum method is reaction, to counter or create an anti force to the vibration, thus neutralize it
it is just easier for me to assemble the store bought pendulum ;D
Yes, barrels vibrate in 360 degrees.+1
Since all this is in the educated trial and error part of development I don't think there is a clear winner in which configuration works best.
I think we're in the "not know the effect of the dampers" on the barrel harmonic mode. Whether liquid filled or dry even. I could see where the dry dampers will react quicker and thus may be better for higher frequency cancelation. The oil filled dampers may be more suited to lower frequency vibrations. Maybe one of each or two of the same configuration would also work, kinda like anti-squirrel mentioned earlier.
I don't know anything. ;D But, if I had a choice of mounted to the side of the barrel versus surrounding the barrel, and if they were both equally effective, I would choose surrounding the barrel for aesthetics. ;D
Thanks,
Taso
I dont know, but could be everyone is over thinking this. I spent a good amount of time Googling and reading on this subject. I even found post where O-Rings were placed on the barrel and moved to where best groups were produced. Another one had a flip-flop hanging from the barrel, not pretty but effective.
Maybe think less is actually more, but like I said, I dont knowI
I dont know, but could be everyone is over thinking this. I spent a good amount of time Googling and reading on this subject. I even found post where O-Rings were placed on the barrel and moved to where best groups were produced. Another one had a flip-flop hanging from the barrel, not pretty but effective.
Maybe think less is actually more, but like I said, I dont knowI
Not trying to take ANYTHING away from Knife's discovery, but I DID notice an improvement in my groups when I simply added a DIY PVC slip on LDC to my Nova Freedom.
The ping from the hammer hitting the valve was reduced considerably and the groups were noticeably tightened.
Just my anecdotal opinion, like the rest of them here.
I see a little confusion between absorbing the harmonics and countering them.
We have a grasp on what adding weight or stiffening the barrel does. We do not understand the effects of the reactive mass (sand/lead shot).
If you want to argue with Varmint Al, then more power to you.... he knows a lot more about this than I ever will.... Your idea of mounting a harmonic tuner in rubber is unique, I have never seen it used by the .22 rimfire benchrest crowd.... If it can be proven to work, they will jump on it immediately, as they have a pretty good handle on what works and what doesn't.... Like everyone is suggesting, build it and see.... Try it with and without the rubber, to determine which is best.... ;)
Bob
Here ya'll go, chew on this awhile...
https://www.gatewaytoairguns.org/GTA/index.php?topic=137566.msg1387963#msg1387963 (https://www.gatewaytoairguns.org/GTA/index.php?topic=137566.msg1387963#msg1387963)
George blew me away with his tenacity and knowledge. His collection of toys and the fact that he pretty much mastered them all is mind boggling. I mean, the guy literally went into his attic and pulled out stuff most of us don't even know exists.Here ya'll go, chew on this awhile...
https://www.gatewaytoairguns.org/GTA/index.php?topic=137566.msg1387963#msg1387963 (https://www.gatewaytoairguns.org/GTA/index.php?topic=137566.msg1387963#msg1387963)
Wow, that was some heavy duty work by those two! Very impressive. That pistol all instrumented was something:
(https://www.gatewaytoairguns.org/GTA/MGalleryItem.php?id=6502)
As for motion of the barrel, George was getting some complicated acceleration patterns from two accelerometers mount top and side of the muzzle--it wasn't simple.
TasoDon,
That is the same thing I found,
"A patented POWDER Compound", is several devices I found on line etc.
No reference to what type of powder compound, so far. ;)
If the patent # is given, and you could find the info in the patent office,
it might list what type of powder is used inside etc.
Tia, Don
I found the patent number on the packaging label: 5016602
Thanks,
Taso
Mole 2017
Very impressive photo,
A question if I can ask,
Would the bbl band/front sight, change any of the acceleration patterns from two accelerometers,
that were mounted on the top and side of the muzzle and or length of the bbl involved?
I have started reading that post, but most of it is over my pay grade.
Tia,
Don
I dont know, but could be everyone is over thinking this. I spent a good amount of time Googling and reading on this subject. I even found post where O-Rings were placed on the barrel and moved to where best groups were produced. Another one had a flip-flop hanging from the barrel, not pretty but effective.
Maybe think less is actually more, but like I said, I dont knowI
Not trying to take ANYTHING away from Knife's discovery, but I DID notice an improvement in my groups when I simply added a DIY PVC slip on LDC to my Nova Freedom.
The ping from the hammer hitting the valve was reduced considerably and the groups were noticeably tightened.
Just my anecdotal opinion, like the rest of them here.
I don't see EITHER bench rest shooter HANGING A WEIGHT UNDER THEIR BARREL.
I wish someone with a bow damper on their rifle to SHIFT IT 90* if the accuracy is still there..
My point is/ most of the air rifle barrel are PREDRILLED. for the transfer port and no way to predict witch way the harmonic will be .. If it vibrate side to side, the hanging weight will act as a pendulum.
Enough said for me.... It is very hard to explain something nobody want to hear.
Yes higher power shooting need reduce or adjust vibration especially at using light and long barrels.
The question only is which is the easiest and also universal way :
1. Barrel stiffening via CF tube
2. Barrel stiffening and longitudinal tensioning via CF tube and nut
3. Barrel fixing/tensioning to the air tube whit band may act the same as additional weight ??? We only be sure that the air tube does not deforms by pressure changing.
4. Adding heavy LDC
5. Adding some extra fixed weight
6. Adding some extra elastic weight(Harmonic DAMPER ? )
7. If velocity is not absolutely stable we can tune it for particular distances via moving them.
For now I only use 1 and 3 and I do not understand fully the different between 5 and 6.
Why are you preferring number. 6 ?
Perhaps I am misunderstanding what you are trying to build.... but sliding a weight along the barrel is basically trying to change the harmonics so that the pellet arrives at the muzzle when it is pointing in a consistent direction.... In other words, you are tuning the barrel for a specific pellet and velocity, exactly what the rimfire benchrest shooters do.... This harmonic tuner I made does the same thing....
(https://i378.photobucket.com/albums/oo221/rsterne/6mm%20Sporter/Harmonic%20Tuner_zpsejrausfr.jpg) (http://s378.photobucket.com/user/rsterne/media/6mm%20Sporter/Harmonic%20Tuner_zpsejrausfr.jpg.html)
The threaded steel sleeve is screwed onto the barrel and tightened in place.... The brass weight moves back and forth to tune the vibration of the barrel to your pellet and velocity.... It is 28 TPI, so it only moves 0.003" for each "hour" (30 deg.) you turn it.... I have not had the opportunity to do much testing, but I understand movements as small as 0.002-0.010" can make a big difference in group size, depending on the weight you are moving back and forth....
The difference between moving a solid weight and using a mass of "lead slush" (or mercury) is that I think the latter would have a wider "sweet spot", and be less critical on placement.... The reason I suggest that, is that if with one pellet and velocity the barrel is not moving much, the damper effect would be small.... However, with another pellet and velocity, that is not shooting well because the barrel is whipping around, the damper should have more effect.... That, logically, to me would be why it seems to work better on improving "poor" bullets or pellets.... The moving shot "damps" the vibration, rather than "tuning" it to a given frequency like moving a solid weight does.... JMO....
I have been giving more thought to the viscosity of the oil in the damper, and I think the "thinner" it is, the better.... We are dealing with a very short duration event here, the pellet is only in the barrel for about 3 mSec (0.003 sec.)…. At 850 fps, it travels the last 2" of the barrel in just 0.2 mSec.… As viscosity increases, the fluid takes longer to move for a given force applied to it.... Think about dropping a single #8 shot onto grease, heavy gear oil, light hydraulic fluid, or water.... It might take days for it to make a dent in the grease, a minute or more to drop an inch through the heavy gear oil, a second or two through the light hydraulic fluid, and almost no delay through the water, even though the water is more dense (ie oil or grease float on water)….
Mercury is probably the ideal fluid, because it is nearly twice as dense as lead shot (13.6 vs. 7.0), so the same weight takes up half the volume.... In addition, it's viscosity is only 1.5 (water being 1.0), whereas a light hydraulic oil (like the power steering fluid I used) is about 80, and 30W motor oil is about 350.... Simply put, for a given force applied, the lighter the oil, the faster the lead shot can respond to the barrel vibration.... and it doesn't have long to respond during the 0.0002 sec. it can affect the flight of the pellet.... Mercury can respond even faster....
Bob
Wow, the MAD Pipe* is picking up speed!! Awesome! ;D
*Mike's Accurizing Dampener Pipe
Amen! In school I always drove me crazy to hear "dampener". Damped motion is what where are talking about, not dampened :)Wow, the MAD Pipe* is picking up speed!! Awesome! ;D
*Mike's Accurizing Dampener Pipe
Corrected term to remove implied use of water! Correct word is DAMPER!
And that is only 1 variable to add to the picture.. In my view , this viscosity damper would only make sense if was apply CONCENTRIC TO THE BORE.. The weight ADDITION of this device is only LIMITING the amplitude and the amplitude being outward in a 360* chase, you have 50/50 chance to put the weight ALIGN with the vibration.. I don't want to discourage people thinking and development of this kind of ENHANCE DEVICE but, I want the good input being translate to a more PRODUCTIVE collective effort developing this device.. Good luck in your effort..
Great news mike , maybe Donny just has too much in his plate . Please tell us it’s not BWaltonpcp. Hahahaha
No problem Michael. I'm just pulling my contribution weight too! ;)
Michael, maybe suggest if they can make a model that extends rearward over the barrel and also allows you to attach an ldc to the muzzle end? Two devices added to the end of the barrel, if I understand correctly, will make the overall length a little too long. ;D
Thanks for all you are doing Michael!
Taso
It seriously nice to awaiting for best solution for DAMPER.
Sorry for mistaken you but these thread focused me back to SPA M30 concept.https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=132262.0;attach=216752;image (https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=132262.0;attach=216752;image)
I like solution all in one.
What about to add some thread, nut and also believable washers for tensioning the barrel? Front part of air tube may be eventually also fill whit mercury to act as flexible DAMPER.
Bigger/500cc and 300 bar air tube at future M30 bullpup version will gladden me too.
The device for me is intended for bench work. For long range varmint and possibly competition. With it static on a bench, the settling is not an issue.
My device is heavy. Too heavy for hunting. At 14.something oz's. Don't remember exactly right now. This included the mounts.
On the other hand, I have always found a heavy, stable platform beneficial in bench work.
Allen, I would love to see you actually contribute by possibly testing yourself, rather than spending all you time being negative. It is kinda getting a little old. All negative comments have no place here.
My Grandmother always said, "Can't never could do a thing". I'm not that nice.
I'm more in the Put up or Shut Up camp. Time for you to put your theories to the test, or let us get on with the work at hand.
Just Say'n!
Knife
Did I just quote myself?
Old age and senility in full force. ;D
JoeTotal weight as pictured is 4.63 OZ
As pictured,
What is the total weight of your MAD device?
Tia,
Don
And that is only 1 variable to add to the picture.. In my view , this viscosity damper would only make sense if was apply CONCENTRIC TO THE BORE.. The weight ADDITION of this device is only LIMITING the amplitude and the amplitude being outward in a 360* chase, you have 50/50 chance to put the weight ALIGN with the vibration.. I don't want to discourage people thinking and development of this kind of ENHANCE DEVICE but, I want the good input being translate to a more PRODUCTIVE collective effort developing this device.. Good luck in your effort..
Alain, what is your current MAD device set up like? i see that you lean towards the concentric design, but most people have had success with MAD mounted under the barrel. why would you discard that fact?
i know some didnt get the improvements including Bob, but most have seen better groups. i also think it takes time to get the right combination to work...JMO.
i am designing a concentric type but only because it appeals better. my design will have 4 longitudinal chambers that houses lead shots individually so that the weights will distribute evenly around the bore. not just under the bore. we will see how it goes when i have time to go to the range.
the chambers will divide at 1:30 oclock through to 7:30 oclock and 4:30 to 10:30.
from 10:30 to 1:30 is the first chamber. 1:30 to 4:30 is second, 4:30 to 7:30 is third and 7:30 to 10:30 is fourth.
never mind i said "evenly" it still is bottom heavy but there will be some weight at the top chamber. and weights on 2nd and 3rd chamber will be more lateral.
The device for me is intended for bench work. For long range varmint and possibly competition. With it static on a bench, the settling is not an issue.
My device is heavy. Too heavy for hunting. At 14.something oz's. Don't remember exactly right now. This included the mounts.
On the other hand, I have always fund a heavy, stable platform beneficial in bench work.
Allen, I would love to see you actually contribute by possibly testing yourself, rather than spending all you time being negative. It is kinda getting a little old. All negative comments have no place here.
My Grandmother always said, "Can't never could do a thing". I'm not that nice.
I'm more in the Put up or Shut Up camp. Time for you to put your theories to the test, or let us get on with the work at hand.
Just Say'n!
Knife
Did I just quote myself?
Old age and senility in full force. ;D
"yeah Mike, why the heck did you not tell us that this is for bench rest only? i am a hunter dang it! "
RayDon,
FWIW,
You may want to increase your mercury weights, to see the results,
if you have enough material, double the weight and re shoot for results etc.
How far behind your LCD is the weight?
Any possibility to move the weight right to the end of the LCD?
I seen a slight improvement on moving my MAD 4", to end of bbl etc.
I am running 6.40 oz of weight + clamp and can see the differences in group size @ 40 yds,(14.3/930 fps)
awaiting the rest of the heavy weight pellets to get here so I can do the before/after MAD tests etc,
at 50 yds. ;)
Tia,
Don
Michael,
"No good deed goes unpunished"
I am amazed at how some people can have any complaint or criticism of a forum member freely sharing a discovery that showed promise for the advancement of our hobby.
No guaranties were implied by Michael.
All he asked was that you share your success and failures so that the discovery can be fleshed out and refined so that all forum members could benefit.
I have limited time and tools to do any fabrication and testing. I bought some archery dampers from ebay that turned out to be of the particle variant. Once I get my barrels back from JSAR to be machined I will try out my dampers and post my findings.
Keep up the good work to everyone who has spent and continues to spend resources on testing this discovery and reporting their findings. ;D
Thank you,
Taso
Once again , I have nothing to add regarding further testing but what I do have is input on uses . As far as I am concerned ,even if this was some sort of snake oil cure for poor accuracy I was able to improve my shooting from possible placebo effect I am going to continue using the devise .
What the devise did for me was improve groups shooting slugs plain and simple . It is 2.5 “ long and is not going to interfere when I go hunting so I will be using it for that as well as when I’m plinking or shooting groups on paper all at various distances . What the devise did not do is make a poor gun any better , improve the ergonomics , make the rifle more efficient or increase the size of my .....
I’m sure with the input from others from testing other filling material , sizes and weight we will get down to what works and what doesn’t . I’m absolutely certain I can improve on my original and my second version that Knife has . I certainly won’t be insulted nor will I care if someone improves on my design , I actually hope someone nails the design so we all benefit .
When you change the oil's viscosity, or the shot size, you are changing the damping forces on the barrel. When you shift the location of the device, you are changing frequencies and modes of vibration, which also can change the effectiveness of the damping force.
this is a simple explanation but it gives some insight into how it works. i know you mentioned trial and error is best. but is there actually some mathematical solution to this to determine the best weight NOT based on caliber but FPE? you know the feeling even if the current device works, but what if its not the best and requires more T&E.
At 900 fps, the pellet is in the barrel about 3 mSec. (0.003 sec)…. However, it travels the last 1" in about 0.1 mSec. (0.0001 sec), and the direction that last inch is pointing determines the departure angle of the pellet.... For a pellet to hit 2" different POI at 50 yards, the muzzle departure angle is changing only 4 MOA (assuming that is the only reason for the POI change)…. I think that means that angle change must be occurring in 0.0001 sec....
I would suggest that the disturbing force causing the barrel to vibrate is likely somewhat proportional to the energy input (the FPE)…. but that is resisted by the barrel mass (so the heavier the barrel + damper the less amplitude)…. However, the frequency and amplitude will be somewhat inversely proportional to the barrel stiffness.... In other words, 10 times the FPE in a barrel that is 10 times as stiff may have a similar amplitude, but assuming the same length, the stiffer barrel would have a higher frequency.... I certainly do not have the brain power to contemplate such calculations....
Bob
say that an airgun at 100fpe is able to vibrate the barrel at a constant frequency and amplitude
well now, it sounds to me like we have the recipe but no one knows when to throw them in the pot. even if we have parts of the recipe it will turn out something if we just throw it in the pot.
let me break it down and maybe we can work from there. no Phd required, i am not qualified but having a little Magnetic resonance education, i 'd like to "take a crack at it" as Texans here like to say.
Lets define the problem. the problem is clearly the barrel vibration. this can be minimized with a secured barrel band at the very end of the barrel or having some dampening or harmonic balancers in place. and since we are building a dampening system, we want to find the ideal weight and fine tune it later. this is the reason we are pursuing a mathematical equation. even though we have some data and can do trial and error but we want a good starting point.
lets convert all calibers into FPE and say that an airgun at 100fpe is able to vibrate the barrel at a constant frequency and amplitude and that An unknown weight can counter. now were just need to put it into an equation and work it out. for example, we know 14oz works for 95-100fpe from Knife's report. what was his frequency and amplitude? is 14oz the best weight or will 10oz be best?
forget every other detail like angle of exit and such. those will be solved when the barrel doesn't flex as much by having a clamp or a device capable of doing such.
well, can we all brainstorm a little and come up with an equation? i think we also need a man who has the equipment to measure the frequency and amplitude.
I haven't looked in a couple days, but when I did I couldn't find a general conclusion online on how our experimental damper can be tuned to each individual gun. Taso
Taso
This could be a possible way to tune for each individual gun, ie,
Have a basic damper, weigh it with clamp mount included etc,
find a pellet/slug that doesn't show any accuracy etc.
Attach the damper and shoot the ammo, see the results,
then fill the damper with a know amount of what ever fluid/shot/sand/mercury etc, 1 oz at a time,
re shoot for accuracy etc, keeping adding weight (1 oz)? until you find the results that work or doesn't,
while keeping notes as to psi/fps range, type of rifle etc, etc.
Try a second bad pellet/slug, repeat the above test until you get results,
note the info, repeat with other pellets/slugs.
After several tests, you should be able to say that, xyz amount of filler for this pellet gave these results,
if all the testers followed the same operation, then a possible scale should show up to give a pattern to follow, etc.
Just some random ramblings from my end. Your thoughts or suggestions, ;)
Tia,
DonI haven't looked in a couple days, but when I did I couldn't find a general conclusion online on how our experimental damper can be tuned to each individual gun. Taso
I believe Ive come up with a way to make a unit that should work with any power plant I talked with Michael about it in detail and will start construction as soon as I can, it will be somewhat elaborate to produce so give me some time but i think it should work with about anything its attached to.
Okay Rich, I really like the pill bottle on the rifle, you can point it and say
"Okay Mr squirrel, it's time for you to take your medicine!" L.O. L.
Okay Rich, I really like the pill bottle on the rifle, you can point it and say
"Okay Mr squirrel, it's time for you to take your medicine!" L.O. L.
LOL. Here's the best part the bottle originally had oxycodone pills in it (from a recent surgery). I figured it was appropriate for calming down the barrel vibrations ;) .
There's certain things that are a given, such as a shorter/stiffer/thicker barrel will oscillate at a higher frequency Why? Stick a ruler over the end of the desk and smack it.
A longer/softer/thinner barrel will oscillate more and likely has a lower resonant frequency.
Adding weight to the end changes things, of course, and adding more barrel clamps will "shorten" the end that oscillates. Adding more mass to the end (not an adjustable weight) will likely drop the frequency/increase the oscillation if I remember my wave theory, but at this point, I'm perfectly happy to sit back and read.
There's certain things that are a given, such as a shorter/stiffer/thicker barrel will oscillate at a higher frequency Why? Stick a ruler over the end of the desk and smack it.
A longer/softer/thinner barrel will oscillate more and likely has a lower resonant frequency.
Adding weight to the end changes things, of course, and adding more barrel clamps will "shorten" the end that oscillates. Adding more mass to the end (not an adjustable weight) will likely drop the frequency/increase the oscillation if I remember my wave theory, but at this point, I'm perfectly happy to sit back and read.
Agree. And the frequency is most sensitive to changes in the length.
Found these formulas for estimating natural frequency of simple systems on the inter-web:
http://www.me.utexas.edu/~dsclab/leks/DSC_Vibration_Modeling.pdf (http://www.me.utexas.edu/~dsclab/leks/DSC_Vibration_Modeling.pdf)
Check out appendix C, formula (C-33) and appendix D, formula (D-10). First is the barrel only, second approximates the barrel with a weight on the end.
Here is a pretty good overview of spring mass damper theory:
http://www.me.utexas.edu/~dsclab/leks/DSC_Vibration_Modeling.pdf (http://www.me.utexas.edu/~dsclab/leks/DSC_Vibration_Modeling.pdf)
Eqn (21) in this is equivalent to the result in appendix D in the above link.
I drew up another design, this time for a double damper with one chamber each side of the barrel....
(https://i378.photobucket.com/albums/oo221/rsterne/Parts%20for%20Sale/Double%20Damper_zpsqwvho0k8.jpg) (http://s378.photobucket.com/user/rsterne/media/Parts%20for%20Sale/Double%20Damper_zpsqwvho0k8.jpg.html)
The holes could be any size you want, also the hole for the barrel.... You could use setscrews to slide it along to adjust the position.... The advantages are that it moves the weight of the shot up close to the barrel C/L, it isn't in the way of the scope, and it would work with a full length reservoir, providing there was about a 1/8" gap between the reservoir and barrel or shroud.... It also eliminates one other concern I have with the concentric designs, where they have limited clearance between the inner and outer tubes for the shot to move around in (the shot has to climb up between the inner and outer tubes)….
If you don't have access to a machine shop, you could probably fabricate this by using copper tubing and end caps, soldered to a thin flat plate that goes across the two tubes, leaving enough room for the barrel between them.... A simple clamp, with a couple of screws below the barrel could provide the clamping action, or even cable ties....
Bob
The advantage of 3D printing a damper, Matt, is that you could close the ends, leaving one end thick enough, and with a hole, that could be tapped for a removable plug to fill it or change the mass or fluid.... If the hole was 11/32", it could be tapped to 1/8" NPT for a pipe plug.... providing the printed material was strong enough for threading, of course....
Bob
I took a hint from George Schmermund. I don't have the high tech equipment, so I downloaded "spectrum analyzer pro " on my smartphone. I use a Samsung S9, it has a sound processor that operates at 48000 hz, so these frequencies can be analyzed by using the built in microphone.
His 2240 ( iirc ) had a 133 hz harmonic. By tapping on the barrel of my 2240 with 14 inch barrel I found a harmonic at 193 Hertz. I tapped on the barrel of my new Hatsan Flash QE, it has a harmonic at 366 hertz.
I did not hear the 2240 at all because the human ear cannot hear much below 200 hz, but I can definitely hear the Flash.
If I can figure out how to duplicate those frequencies then I may be able to try the dampers without wasting ammo.
My device is heavy. Too heavy for hunting. At 14-something oz's.
By tapping on the barrel of my 2240 with 14 inch barrel I found a harmonic at 193 Hertz. I tapped on the barrel of my new Hatsan Flash QE, it has a harmonic at 366 hertz.
I did not hear the 2240 at all because the human ear cannot hear much below 200 hz, but I can definitely hear the Flash.
If I can figure out how to duplicate those frequencies then I may be able to try the dampers without wasting ammo.
Did you tap on the shroud of the Hatsan, or the unshrouded barrel?The Flash doesn't seem to have a shroud, it has a pickle. I very well could be wrong about that. I did not remove anything from either of them.
Could you attach a damper to the barrel, and the tap it and record the frequency and see if it dies away faster than without the damper?
QuoteDid you tap on the shroud of the Hatsan, or the unshrouded barrel?
. . .
The Flash doesn't seem to have a shroud, it has a pickle. I very well could be wrong about that.
Update:
Okay, you are correct, the Flash DOES have a shroud. ⁰ The harmonic that I reported was not the harmonic of the barrel, it was the shrouded barrel.
Even with the shroud, it's still about the same size as any pb.
Just out of curiousity, let's say you can accurately determine the primary frequency (Mode 1) and the first secondary frequency (Mode 2) for you barrel, either through measurement, or calculation.... Do you want the Damper to have the same resonant frequency, or something completely different, in order to cancel out the barrel resonance?....
Just asking, 'cause I haven't a clue.... ???
Bob
Sorry, I don't understand that answer....
According to Varmint Al's website on barrel vibration, the frequency of the Mode 2 vibration (one node) is about 5 times as high as the Mode 1 (cantilever bending from the receiver) using a tapered barrel....
https://www.varmintal.com/amode.htm (https://www.varmintal.com/amode.htm)
Further down the page, he gives the frequency calculations for a straight cantilever beam, 1/2" sq. x 20" long.... and Mode 2 is about 6.25 times the frequency of Mode 1 (251 Hz. vs 40 Hz.)…. Nowhere do I see a relationship for 1/4 wavelength....
Here is another calculator you may find interesting, by Geoffrey Kolbe....
http://www.geoffrey-kolbe.com/articles/rimfire_accuracy/barrel_vibrations.htm (http://www.geoffrey-kolbe.com/articles/rimfire_accuracy/barrel_vibrations.htm)
However, the chamber pressure used is 50,000 psi, with the pressure profile of a .308 Winchester (7.62 NATO) cartridge.... However, it will show what happens when you add, for example, a muzzle weight....
Bob
Just out of curiousity, let's say you can accurately determine the primary frequency (Mode 1) and the first secondary frequency (Mode 2) for you barrel, either through measurement, or calculation.... Do you want the Damper to have the same resonant frequency, or something completely different, in order to cancel out the barrel resonance?....
Just asking, 'cause I haven't a clue.... ???
Bob
Just out of curiousity, let's say you can accurately determine the primary frequency (Mode 1) and the first secondary frequency (Mode 2) for you barrel, either through measurement, or calculation.... Do you want the Damper to have the same resonant frequency, or something completely different, in order to cancel out the barrel resonance?....
Just asking, 'cause I haven't a clue.... ???
Bob
Just out of curiousity, let's say you can accurately determine the primary frequency (Mode 1) and the first secondary frequency (Mode 2) for you barrel, either through measurement, or calculation.... Do you want the Damper to have the same resonant frequency, or something completely different, in order to cancel out the barrel resonance?....
Just asking, 'cause I haven't a clue.... ???
Bob
FWIW I don't think the damper works by a natural frequency that is countering the vibration modes of the barrel. I think it dissipates the kinetic energy of the barrel motion. The natural frequency of an object is the frequency at which it oscillates after being subjected to an initial temporary disturbance. This vibration always dies away eventually because there is internal damping present in most structures, or objects. Damping makes the vibration die away more quickly.
As an analogy, a bell or a tuning fork when struck in air, will ring at some frequency. If you put a ringing tuning fork in a pot of oil, the sound will stop quickly. If you put the tuning fork in oil before you strike it, it will have more of a thunk sound. This is because the oil is damping (absorbing) the amplitude of the vibration. This may be how the damper is working on the barrel of the rifle.
I don't think the damper works by a natural frequency that is countering the vibration modes of the barrel. I think it dissipates the kinetic energy of the barrel motion.
Just out of curiousity, let's say you can accurately determine the primary frequency (Mode 1) and the first secondary frequency (Mode 2) for you barrel, either through measurement, or calculation.... Do you want the Damper to have the same resonant frequency, or something completely different, in order to cancel out the barrel resonance?....
Just asking, 'cause I haven't a clue.... ???
Bob
FWIW I don't think the damper works by a natural frequency that is countering the vibration modes of the barrel. I think it dissipates the kinetic energy of the barrel motion. The natural frequency of an object is the frequency at which it oscillates after being subjected to an initial temporary disturbance. This vibration always dies away eventually because there is internal damping present in most structures, or objects. Damping makes the vibration die away more quickly.
As an analogy, a bell or a tuning fork when struck in air, will ring at some frequency. If you put a ringing tuning fork in a pot of oil, the sound will stop quickly. If you put the tuning fork in oil before you strike it, it will have more of a thunk sound. This is because the oil is damping (absorbing) the amplitude of the vibration. This may be how the damper is working on the barrel of the rifle.
That is Logical thinking.. ;D. The damping would be greater if the fluid is thicker RIGHT????
Increasing the viscosity of the oil makes it more difficult for the lead shot to move, which is what it needs to do to absorb the barrel's vibrational energy.... Think about imbedding the lead shot in peanut butter and you get the idea.... you may as well just have a solid lead mass, IMO....
The more I think about it, the more I like the idea of using Mercury.... It has twice the density of lead shot, and a very low viscosity, only slightly greater than water.... and it has a viscosity index higher than water (the viscosity hardly changes over the temperatures we shoot at)…. JMO....
I found some more information on particle dampers because I want to understand them better, and I'm a glutton for punishment! ;D
...
I also found a commercial particle damper for a rifle that uses tungsten powder, I believe. Good suggestion HunterWhite! ;)
http://www.ezellcustomrifles.com/home-3/pdt-tuners/ (http://www.ezellcustomrifles.com/home-3/pdt-tuners/)
It looks smaller than our designs but I have not found out if the Ezell PDT tuner is effective or not.
And the published document link is broken but I think this is the document they're referencing:
https://oaktrust.library.tamu.edu/bitstream/handle/1969.1/1459/etd-tamu-2003C-AERO-Marhadi-1.pdf?sequence=1&isAllowed=y (https://oaktrust.library.tamu.edu/bitstream/handle/1969.1/1459/etd-tamu-2003C-AERO-Marhadi-1.pdf?sequence=1&isAllowed=y)
Thanks,
Taso
Maybe magnetic damping ???
I'm I the only one considering the therapy sole gel???
That medium is well known for ABSORBING SHOCK AND VIBRATION..
AS a miner of trade, I use the new HALF GLOVES with inserts of gel covering the palm entirely when I drill with the JACKLEG..
I'm I the only one considering the therapy sole gel???
That medium is well known for ABSORBING SHOCK AND VIBRATION..
AS a miner of trade, I use the new HALF GLOVES with inserts of gel covering the palm entirely when I drill with the JACKLEG..
Alain,
It's been done. It's called the Sharpshooter X-Ring Barrel Dampener.
https://limbsaver.com/products/sharpshooter-x-ring-barrel-dampener (https://limbsaver.com/products/sharpshooter-x-ring-barrel-dampener)
This thread is exploring something different.
Thanks,
Taso
...
I couldn't get my head around how our 1 pound particle dampers could cancel the barrel vibrations satisfactorily. I was initially thinking it was one damping event. But then when I realized we have a certain amount period cycles in our barrel vibration before the pellet exits the muzzle, we have multiple damping opportunities. Hopefully the amplitude and frequency will decrease after every damping cycle so that the eventual result is no more vibration?
...
Taso
I wonder if this material wrapped a couple time around the barrel would work. Wouldn't be hard to try.
https://designengineering.com/boom-mat-flex/
I wonder if this material wrapped a couple time around the barrel would work. Wouldn't be hard to try.
https://designengineering.com/boom-mat-flex/
It sounds like that
" motorcycle seat gel pads shock absorber mat "
Might work really well on the butt stock. 😆
I'm I the only one considering the therapy sole gel???
That medium is well known for ABSORBING SHOCK AND VIBRATION..
AS a miner of trade, I use the new HALF GLOVES with inserts of gel covering the palm entirely when I drill with the JACKLEG..
Alain,
It's been done. It's called the Sharpshooter X-Ring Barrel Dampener.
https://limbsaver.com/products/sharpshooter-x-ring-barrel-dampener (https://limbsaver.com/products/sharpshooter-x-ring-barrel-dampener)
This thread is exploring something different.
Thanks,
Taso
I wonder if this material wrapped a couple time around the barrel would work. Wouldn't be hard to try.
https://designengineering.com/boom-mat-flex/
I don't want to demolished your theory but, when I introduce my taught on using rubber oring supporting a weighted sleeve over an existing LCD, the WARM WELCOME I RECEIVED make me dish my comments and keep the results for me.
I wonder if this material wrapped a couple time around the barrel would work. Wouldn't be hard to try.
https://designengineering.com/boom-mat-flex/
I don't want to demolished your theory but, when I introduce my taught on using rubber oring supporting a weighted sleeve over an existing LCD, the WARM WELCOME I RECEIVED make me dish my comments and keep the results for me.
Think happy thoughts.
That’s what “Brain Storming” is all about.
I don't know if the brainiacs here have noticed, but all this theory and what if's has completely derailed the thread.
Test is what this thread called for. Many posters have completely been run off due to the complete hard turn it has taken. It completely pushed the everyday shooter out. Which is exactly who the thread was intended for.
Test or move on please!
Please start a new thread for all this maybe/maybe not theory.
For all those that have actually worked hard and tested, both successful and not so, Thank You All. Keep it up. A wealth of info is being generated for us all to benefit from . We don't work in a lab. It is mostly, useless info for the shooters here.
The testers work is on the other hand very to the point and can be duplicated by all.
Once again, Thank You All!!!
Knife
So Ray!! You are saying that the device is SITTING on oring???
How much are you Attribute the oring in the improve accuracy??
Have you try the device without the oring??
BTW! Nice shooting..
nice improvement .......I like the boring bar idea, a free weight suspended by rubber... I wonder if a metal sleeve slid over the o-rings would yield even better results, same principal as the bore meister, but in reverse, with the weight on the outside. I have plans in my head to try this idea and felt using o-rings would be a quick and easy way to test
Ray
Neat Idea with the "O" rings. Question for you,
What does 20 of these "O" rings weigh, total weight?
Tia,
Don
Ray
Neat Idea with the "O" rings. Question for you,
What does 20 of these "O" rings weigh, total weight?
Tia,
Don
Wondering the same thing...
Ray
Neat Idea with the "O" rings. Question for you,
What does 20 of these "O" rings weigh, total weight?
Tia,
Don
Wondering the same thing...
20 weigh 34 grams which is right at 2 ounces.
28.3 grams = 1 oz 1.7 g each seems highRay
Neat Idea with the "O" rings. Question for you,
What does 20 of these "O" rings weigh, total weight?
Tia,
Don
Wondering the same thing...
20 weigh 34 grams which is right at 2 ounces.
28.3 grams = 1 oz 1.7 g each seems highRay
Neat Idea with the "O" rings. Question for you,
What does 20 of these "O" rings weigh, total weight?
Tia,
Don
Wondering the same thing...
20 weigh 34 grams which is right at 2 ounces.
Rich
Very interesting groups size and info, Question for you, What was the fps for this testing?
Between 4-5 oz rating seemed to be the changing point, in group size, for your rifle/loading etc.
If possible, can you re shoot these same tests, and starting at 4 oz,
increase the weight by 1/4 oz per test, keeping every thing the same as the first test etc.
Then you can see if a greater increase/decrease of the group sizing etc,
occurs with just the quarter oz weight increase.
As another thought/test, find the worst accurate shooting pellet, and try your test on it,
it might prove to be worth the testing etc.
Tia,
Don
As I see it, here are some of the variables....Here's my contribution to KnifeMaker's MAD concept. This configuration, being tunable for weight, viscosity, solving the gravity issue of a large tube filled with settling shot, may work to place a damper on recoil as well as placement along the barrel or moderator to dampen barrel whip and therefore tighten group size. It could be mounted in a rubber cylinder type boot, with up to six tubes, or it could be solidly clamped in this type of configuration, depending on the rifle's needs of course.
Variables affecting the force, acceleration and vibration generated:
FPE (further broken down into)
Bullet weight
Rifle weight
Velocity (critical in determining when the bullet arrives at the muzzle, relative to node location)
In addition, possibly air pressure and dwell (how they effect the vibration and bullet arrival time at the muzzle)
Variables affecting the frequencies and modes of vibration of the barrel:
Barrel OD (stiffness varies with the 4th power)
Caliber (larger bore reduces stiffness)
Barrel Length (longer reduces stiffness)
Material (ie how the dimensions relate to the stiffness)
Barrel Supports (ie free floating, or bands and where positioned)
Direction (plane) of primary barrel vibration (ideally should be vertical)
Variables affecting how the Damper/Tuner interacts with the node location and amplitude of muzzle movement:
Mass of Damper/Tuner (increased mass decreases amplitude and frequency, and decreases horizontal movement)
Position of Damper/Tuner (lengthwise and radially)
Variables affecting the damping effect of the material inside the Damper:
Damping Material (Mercury, Lead shot, powders, fluids, masses on springs, etc.)
Shot/particle size
Fluid viscosity (if any)
Fill ratio of Damper
Internal Shape of Damper
Mounting Position
Any use of springs (mechanical or magnetic)
Mounting method (ie solidly, rubber, etc.)
While it is possible to look at these items one at a time, to a large degree they interact, and changing one thing affects one or more of the others.... I have neither the brain power, or the computer power, to even try and sort through predicting how a given damper/tuner will work on a given rifle/pellet combination.... If you do, then more power to you.... If you don't, then jump in there, build something, and try something to increase our database of knowledge.... 8)
Having said that, I believe that more powerful PCPs may require a larger damping mass.... and the more flexible the barrel, the more effective the damper may be....
Bob
I use to have quiet a bit of mercury. Long gone now. Never had a use for it. Wish I still had it. Would be a natural for this.
Great looking devices Vr. Bob! 8)
Mike
I use to have quiet a bit of mercury. Long gone now. Never had a use for it. Wish I still had it. Would be a natural for this.
Great looking devices Vr. Bob! 8)
Mike
FWIW you can purchase mercury rather cheaply now.