Author Topic: Smith Rev3 build (Read 14935 times))

csdilligaf · « **Reply #20 on:** February 05, 2014, 11:27:31 AM »

I fixed a valve leak that I had and machined in some windows to view the hammer/valve strike. Here is some video at 1000fps.

strever · « **Reply #21 on:** February 05, 2014, 12:19:17 PM »

Chip
good to see you here on GTA
you are a craftsman in the machine shop
and your presence here is bringing out all of the experts
i agree with you on the math these guys spout
but i read and read it again over sometimes 3 or 4 times to try and figure it out
they are very good at what they do and will definitely be helpful
i have been missing yours post
Seans barrel work is very good
and have you checked with Joe Korick for regulator work ? he is VERY good

rsterne · « **Reply #22 on:** February 05, 2014, 12:28:26 PM »

Hammer bounce = YES....

Wasted air = NO, from what I can see....

Pretty typical for a well tuned PCP, IMO....

Bob

csdilligaf · « **Reply #23 on:** February 05, 2014, 01:16:06 PM »

I went frame by frame and it does not open the valve after the first time. Happy with that but I sure would like to come up with an absolute one touch only hammer.

rsterne · « **Reply #24 on:** February 05, 2014, 01:35:56 PM »

I am not a fan of HDDs that rely on friction.... I firmly believe that they will affect the consistency of the hammer velocity, particularly as the temperature changes.... Like you, however, I woudl love to see a hammer that doesn't bounce around, eliminating the possibility of opening the valve a second time and wasting air.... I have seen two designs that SHOULD allow only one strike, one is in the Hatsan PCPs, which have a lightly spring-loaded lever that is pushed out of the way by the hammer on the forward stroke, and catches the hammer on the rebound just a couple of mm from the valve stem, 100% preventing it from storing much energy in the hammer spring.... Yes, the hammer would vibrate in that small space between the lever and the valve stem, but I can't imagine it would have enough energy to reopen the valve.... The other is Michael's electrical solenoid driven hammer, which assuming it is only energized once, shouldn't store any energy on the first bounce as it has no spring....

I have looked at the design of Daystates "slingshot hammer" which has a 2-part hammer where the hammer spring propels the outer section towards a stop, and then the inner section carries on to open the valve through it's own momentum.... It then bounces back, hitting a spring and buffer inside the outer section and in theory preventing any bounce.... However, I have also heard that tests have shown it not to be 100% effective, and it doesn't lend itself well to big bore guns with heavy hammers.... In fact, that is a common trait to all three of these devices, from what I can see....

Bob

csdilligaf · « **Reply #25 on:** February 05, 2014, 02:09:45 PM »

here is the slingshot video. It really is not as bad as I thought.
http://www.daystate.com/huntsman.htm

I had a design drawn up once that used the air discharge from the firing cycle to pop some brake pads on the hammer. To many parts and timing involved so went to something like the Hatsan but never completed it. I did not know Hatsan has something like that. Any info? I know John Bowkett from BSA had some locking mechanism but it has never been posted about. It is on his custom Bowkett BSA's.
Does the Hatsan use the cocking lever to open the jaw so the hammer can retract?

rsterne · « **Reply #26 on:** February 05, 2014, 02:28:14 PM »

Here are some photos of the Hatsan bounce preventer....

The nut is just there as a weight to hold the lever up for the photo.... (replacing the spring force)

As you draw the bolt back, it pushes down on the back of the lever, lifting the front out of the way of the hammer during cocking....

In the third photo you can see the limited amount of rebound room for the hammer, about 2 mm?.... Unfortunately, this tiny lever has been know to break, I have seen photos of several with one leg broken off.... They may have had the hammer spring preload cranked to the max, though....

Bob

lloyd-ss · « **Reply #27 on:** February 06, 2014, 12:06:53 AM »

Chip,
Thanks for posting this. Its good to have some visual evidence of what is happening inside a PCP.
I guess it would be nice to have a hammer that only hit once, but this bounce doesn't seem to be hurting anything. Keep it simple if you can.
Lloyd

SeanMP · « **Reply #28 on:** February 09, 2014, 12:21:52 AM »

BOOYAH!

Hows that for a long winded technical post from the one of the geek gang

That Anshutz trigger is probably the nicest trigger ever made IMO.....truly a marvel of precision.

csdilligaf · « **Reply #29 on:** February 24, 2014, 04:42:11 PM »

Well, I have been working on the stock. It is at 14.2 lbs now and I need a pistol grip and cheek piece. I have some nice Cherry wood left over from the kitchen cabinets that I will use. I still can thin the forearm down and save about another pound if need be but I would like to come in as close to 15 lbs as possible.

michaelthomas · « **Reply #30 on:** February 25, 2014, 12:50:26 AM »

Looks nice, Chip......as usual.

Mike

sgeorge · « **Reply #31 on:** February 25, 2014, 07:38:52 AM »

You certainly don't need a pistolgrip unless you intend on hugging it. Cherry would be a nice touch. Chip Smith, benchrest shooter, has a good ring to it.

csdilligaf · « **Reply #32 on:** February 25, 2014, 10:23:35 AM »

I'll start shooting targets for scores this week. We'll see if "benchrest shooter" is what I call myself after that.

PetefromTn · « **Reply #33 on:** February 25, 2014, 12:17:24 PM »

Lookin' real good Chip....

Nice work man. Can't wait to see how it shoots for ya. Peace

Pete

TimmyMac1 · « **Reply #34 on:** February 25, 2014, 01:31:39 PM »

Quote from: rsterne on February 05, 2014, 01:35:56 PM

I am not a fan of HDDs that rely on friction.... I firmly believe that they will affect the consistency of the hammer velocity, particularly as the temperature changes........ In fact, that is a common trait to all three of these devices, from what I can see....

Bob

There is a awful lot to be said for getting the hammer momentum right to be able to operate free of any devices meant to control Striker rebound and second hits. We bounced on Gen I guns and lowered hammer weight 20% on Gen II to make it go away for the most part. It did not seem to adversely affect accuracy but it is a small air waster to have more mass than needed.
I have to agree with Bob on the friction thing. Does not seem to be any upside to adding any drag that is going to create any variability.

I'd also like to give the Sean Pero barrel a look see. Is it available still and who is the one to talk to?
I also agree whole heartedly with Chip in that the progression of development can come from about anyone with an original thought. I have made changes to my production whenever there was an inspired thought from someone with the kind of insight to look at things from a different perspective and apply what they know and believe to a problem everyone faces.
Inspiration has come from about anyone who makes sense and it is often not geniuses that see things clearest. Dan Brown has been an open book and that kind of attitude is to be applauded. I've tried to be as helpful as I can and encourage anyone who is trying to raise the bar.
I've learned a lot from Bob and it is so cool to have guys like ghim here to be a tutor for the stuff us non-math-guys wouldn't be able to help with.
It is especially gratifying to see the fruitful exchanges here and the guys who have mattered are starting to regularly contribute and congregate. I knew it would happen and I'm very pleased to see threads of this nature develop and give everyone a chance to learn.
When Fruitful minds share the bar will be raised that much quicker.
I'm no machinist by any stretch but I can appreciate the skill set enormously. I have no doubt the world is watching and anticipating the improvements we will see because of this collaborative atmosphere. I really don't care who makes the next large push as long as it is an American. North, South or Central.
I want to let everyone know how much I appreciate the fact that this has become the place to hang out for the died in the wool guys. I knew it would happen and the pace has pleasantly surprised me lately. Very COOL STUFF! Thanks go to everyone participating.

TimmyMac1

rsterne · « **Reply #35 on:** February 25, 2014, 01:40:55 PM »

Shameless plug for a buddy.... seanpero@gmail.com

Bob

csdilligaf · « **Reply #36 on:** February 25, 2014, 02:02:51 PM »

OK, got the butt,grip and trigger gaurd done. 14.6 lbs. So now its time to shoot the shiznit out of it and see what it like's and dont like.

csdilligaf · « **Reply #37 on:** March 09, 2014, 09:23:06 PM »

OK, I tried my first official match with the Smith Rev3. I went up to the Open Grove Match in Oxnard CA. This is a top notch range on personal property and such a great bunch of guys, and gals. I came in 2nd just behind Lindsay and very happy with the gun. First time shooting with wind flags, that is interesting. Lucky for me the were supplied with 4 at each lane but now I am hooked and need to get my own.
So I know you guys have talked about airgun efficiency. I don't know what is good or bad or even how to calculate it. But I got 30 shots(5 sighters and 25 for score) and dropped from 3000 psi to 2500 psi. I was shooting 21.1 grain barracuda's at 850 fps. It is 34 ft lb. What is my efficiency and is that good?

thanks
Chip

AmBraCol · « **Reply #38 on:** March 09, 2014, 09:35:46 PM »

How large is your reservoir?

csdilligaf · « **Reply #39 on:** March 09, 2014, 10:26:54 PM »

I guess that would be important. Shows what I know. It is 445 cc

thanks,

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Smith Rev3 build

Author Topic: Smith Rev3 build (Read 14935 times))

sgeorge