GTA
All Springer/NP/PCP Air Gun Discussion General => Air Gun Gate => Topic started by: RobertMcC on December 16, 2016, 09:12:56 AM
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Made in Nova Scotia. SSP 22 cal shooting 700 FPS. Its very interesting airgun and wouldn't mind seeing it on the market.
Watch the video.
https://youtu.be/Fdh06WhhQME
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That is really a neat design for sure, great video he did too!!!
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there were several 30 yrs ago pushing 12 fpe like the Bowkett.. What I noticed from this video is he has almost no mechanical advantage cocking the gun.. weird
(http://i746.photobucket.com/albums/xx102/robnewyork50/bokett.jpeg) (http://s746.photobucket.com/user/robnewyork50/media/bokett.jpeg.html)
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Interesting design - look forward to seeing more.
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Really fascinating. A pumper making a comeback towards the future... but inspired by the past with it's crossbow shape. It's a prototype so one shouldn't mind its very mechanical style, with such nice performances.
Anyway, thanks for the info. The Webley Paradigm, FX Indy, Quigley or Millenium won't feel alone.
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Talking to the designer. Which I'm no way affiliated with. Just helping a fellow bluenoser out.
He saying that it might be in around 600 CAD when finished for the market.
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What I noticed from this video is he has almost no mechanical advantage cocking the gun.. weird
His mechanical advantage is roughly 2:1, x2 levers to push down the piston.
JMJ
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Say Robert, this looks very interesting to Me. Keep us posted on the progress of this gun if you can. Tell the designer not to sell out to Crosman , Gammo ect. because they will bury this idea. They have too much money invested in gas piston break barrels to let this come to market. Good job and Best Regards - Tom
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What I noticed from this video is he has almost no mechanical advantage cocking the gun.. weird
His mechanical advantage is roughly 2:1, x2 levers to push down the piston.
JMJ
yes.. For comparison your average pumper has a minimal of 10:1
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Say Robert, this looks very interesting to Me. Keep us posted on the progress of this gun if you can. Tell the designer not to sell out to Crosman , Gammo ect. because they will bury this idea. They have too much money invested in gas piston break barrels to let this come to market. Good job and Best Regards - Tom
I will. I'll try and get him to come over here.
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Very interesting rifle.
Look forward to seeing the final product
They did a great job.
Thank you for posting about it
Dave
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Plus 1 for interesting. I hope it goes somewhere.
Thanks for posting.
Higgs
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This one caught my eye before I went to the darker side :o
http://www.gatewaytoairguns.org/GTA/index.php?topic=29394.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=29394.0)
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What I noticed from this video is he has almost no mechanical advantage cocking the gun.. weird
His mechanical advantage is roughly 2:1, x2 levers to push down the piston.
JMJ
yes.. For comparison your average pumper has a minimal of 10:1
My 1377-based pumpers (normal and medium stroke) are 3.5:1, worst case with pump lever at 90 degrees. Avanti 853 (SSP) is 4:1. How are you calculating mechanical advantage?
Fwiw, it's a great design, allowing use of both hands to execute the compression stroke. The low mechanical advantage allows for the long stroke he needs. I was wrong, in that the mechanical advantage appears closer to 1.5:1, but essentially with 2 levers acting in parallel, so 3:1.
JMJ
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I am not sure how the mechanical advantage occurs. I can hold the pump arms at the fulcrum, and still pump it with ease. Seems un natural in a way. All I know it works. In fact, it works so well that our steel tube is going to be 1 1/8" ID which will give us 16 CI of air instead of 12.5 CI. So we should get 20 ft lb,s easy. However we don't really know till we try. Mostly, its a blast discovering what can be accomplished with compressed air. Frustrating at times, but soooooo pleasing when your expectations are surpassed. Originally the goal was to get 12 ft lb,s energy in .22 cal.
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It's a great design, Joe. Nicely executed.
JMJ
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Wow Joe, that's a great idea and I look forward to seeing it hit the market. Looks perfect for just sittin' and shootin'. For me personally I would prefer a slightly less tactical look but I can easily get past that. I do realize it's kind of a frankenstein working prototype at this point. As a proof of concept though it certainly does the job. Congrats on getting this together and the best of luck to you!
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What I noticed from this video is he has almost no mechanical advantage cocking the gun.. weird
His mechanical advantage is roughly 2:1, x2 levers to push down the piston.
JMJ
yes.. For comparison your average pumper has a minimal of 10:1
My 1377-based pumpers (normal and medium stroke) are 3.5:1, worst case with pump lever at 90 degrees. Avanti 853 (SSP) is 4:1. How are you calculating mechanical advantage?
Fwiw, it's a great design, allowing use of both hands to execute the compression stroke. The low mechanical advantage allows for the long stroke he needs. I was wrong, in that the mechanical advantage appears closer to 1.5:1, but essentially with 2 levers acting in parallel, so 3:1.
JMJ
the difference is the toggle lever, or linkage from a pump arm to a piston arm.. Having 2 or 7 levers doesnt change the geometry between his pump lever, toggle , and piston arm.. The force required to move X amount of air remains the same.. Yes , at 90 Degrees there is very little M.e with a normal pumper, but coincidentally its not needed at 90 degrees where theres almost no air being compressed. As the pump arm reaches 45 degrees in a conventional pumper like your 1377 , the ME is already 7to 1 or greater.. But the time the pressure is peaked ( near 15 degrees pump arm angle ) the mechanical advantage has passed 10:1
An easy way to reverse the math on the process for proof is simple..
If a 1377 on the final stroke is pushing a known number , like 1000 psi , we can base all numbers on the diamter of the piston .. ( .620)
So r X r X pi X 1000 psi =301 lbs of rear force to move the piston to the valve face.
Even were the M.e as low as 10:1 , you would need to expend 30 lbs cocking effort on that final stroke to reach the 1000 psi valve pressure ( these numbers seem fairly close
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the great news is pumpers are truly in their infancy.. We dont use any modern technology to translate the mechanical force to compressing air.,. ( eccentric cams , ball bearings, any sort of gear reduction tranny, hydraulic fluid -just to name a few )And the biggest of all is multi stage piston
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Very cool,just tell me where to send my cash...
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Rob, I'm well aware how pumpers work, and I know that the # of levers does not change the lever ratio. I misspoke when I stated that doubles the ratio. Most pumper designs cannot be executed with 2 levers. This opposed lever design cancels some of the reaction forces, increasing efficiency. Very clever.
The vast majority of pumpers use linked levers to move a piston, and the mechanical advantage increases until the piston reaches the valve face before going over center. The basic leverage ratio is the applied force radius over the linkage radius. This is the ratio I was citing, which drives the rest of the math.
Regardless of our spat, this is a really nice design.
JMJ
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there were several 30 yrs ago pushing 12 fpe like the Bowkett.. What I noticed from this video is he has almost no mechanical advantage cocking the gun.. weird
(http://i746.photobucket.com/albums/xx102/robnewyork50/bokett.jpeg) (http://s746.photobucket.com/user/robnewyork50/media/bokett.jpeg.html)
It's sad they went away for whatever reason. That is a nice looking rifle! Do you know - did they fall out of favor because the manufacturers failed; because they had difficulties in their design; or because they were overrun in the market by more powerful rifles?
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I remember seeing a video or two about them a few years ago and talk about them on the forums, but as why it never made mass production, we can only speculate.
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there were several 30 yrs ago pushing 12 fpe like the Bowkett.. What I noticed from this video is he has almost no mechanical advantage cocking the gun.. weird
(http://i746.photobucket.com/albums/xx102/robnewyork50/bokett.jpeg) (http://s746.photobucket.com/user/robnewyork50/media/bokett.jpeg.html)
It's sad they went away for whatever reason. That is a nice looking rifle! Do you know - did they fall out of favor because the manufacturers failed; because they had difficulties in their design; or because they were overrun in the market by more powerful rifles?
Im not sure.. I think this was in the era of the ssp match rifles , and when those were fazed out due to PCPS i guess people lost interest?? I think Bowkett went to work for a major gun manufacturer ,. But they had no mechanical problems at all, they were built like tanks , and can still be bought second hand
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Rob, I'm well aware how pumpers work, and I know that the # of levers does not change the lever ratio. I misspoke when I stated that doubles the ratio. Most pumper designs cannot be executed with 2 levers. This opposed lever design cancels some of the reaction forces, increasing efficiency. Very clever.
The vast majority of pumpers use linked levers to move a piston, and the mechanical advantage increases until the piston reaches the valve face before going over center. The basic leverage ratio is the applied force radius over the linkage radius. This is the ratio I was citing, which drives the rest of the math.
Regardless of our spat, this is a really nice design.
JMJ
the only reason i mentioned it was that must SSPs are really hard to cock , and thats for 5fpe ..
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I want one!!
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Very cool,just tell me where to send my cash...
+1
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If he can do 12fpe for $450 USD, he should have no trouble finding buyers. I will take one for sure.
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It's appears to be a variation of this - https://www.pyramydair.com/blog/2016/12/pump-assist-benjamin-392-part-1/ (https://www.pyramydair.com/blog/2016/12/pump-assist-benjamin-392-part-1/)
Look at the Benjamin pump near the end of the article.
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Really fascinating. A pumper making a comeback towards the future... but inspired by the past with it's crossbow shape. It's a prototype so one shouldn't mind its very mechanical style, with such nice performances.
Anyway, thanks for the info. The Webley Paradigm, FX Indy, Quigley or Millenium won't feel alone.
I hope they enjoy each others company as they sit in my dust.😎
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For those members discussing the mechanical advantage of the pump, its quite simple. At the top of the pump stroke, there is no mechanical advantage. As the distance between the top linkage and bottom linkage decreases, the mechanical advantage increases. By the time the two come together the mechanical advantage has increased exponentially. The pump arms are 20" long, so the last 1/4" of space is 72 to one.
Very similar to air pressure theory. Every time the distance is halved, the mechanical advantage doubles, as does the pressure. since the space between the pump head and valve is about 1/8", then the mechanical advantage is now at 144 to one. so 20" times 144 is 2880,which is about right for the pressure im getting.
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I'm curious. Why the 1/8" gap between the piston, and valve face?? Wouldn't it be more efficient if there was no gap? You would have a higher working pressure if the gap was eliminated. Or, am I missing something?
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I'm curious. Why the 1/8" gap between the piston, and valve face?? Wouldn't it be more efficient if there was no gap? You would have a higher working pressure if the gap was eliminated. Or, am I missing something?
You are right. When the pump head is set during construction, the pump head and valve face, are indeed touching. However there is a 1/32" space under a cap on the valve, and the other 3/32" is only an estimate of how much the linkage moves when under pressure. After about 2500 shots, when I did the video. Things have loosened a little. The 740 fps shot I mentioned in the video, was before everything got so worn out. Also if the full pump stroke were to compress all that air into zero space, it would be impossible. However there is approximately 1 CC of space inside the valve. The new steel gun should get a lot more power if we can find the right metal and hardness. To be very honest though, a powerplant thats capable of high power, but backed off to a lower power, would last a lot longer. Sort of like pumping a multi stroke twice whats is recommended. It can be done, but isn't wise to do so.
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Wear and tear. Makes sense seeing as the prototype is aluminum. I'll be keeping an eye out for the production run. You definitely have my attention.
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The Parker Hale Dragon made around 12 ft/lbs. They made two versions, a standard and a FT version. The FT had a longer barrel and longer cocking stroke - You need to have LOOONG arms to cock it.
(http://i40.photobucket.com/albums/e228/sonofzorro1/ParkerHaleDragon4.jpg) (http://s40.photobucket.com/user/sonofzorro1/media/ParkerHaleDragon4.jpg.html)
(http://i40.photobucket.com/albums/e228/sonofzorro1/ParkerHaleDragon.jpg) (http://s40.photobucket.com/user/sonofzorro1/media/ParkerHaleDragon.jpg.html)
https://www.pyramydair.com/blog/2008/07/parker-hale-dragon/ (https://www.pyramydair.com/blog/2008/07/parker-hale-dragon/)
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Good seeing you here Joe, Need another Nova Scotian here.
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Good seeing you here Joe, Need another Nova Scotian here.
Thanks. Nice to be here.
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Very interesting, subscribed.
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Made in Nova Scotia. SSP 22 cal shooting 700 FPS. Its very interesting airgun and wouldn't mind seeing it on the market.
Watch the video.
https://youtu.be/Fdh06WhhQME
Very cool; I gave a thumbs up on youtube.