Going to extremes with balanced valves

[Stubbers]

If you want to tinker with ever lighter designs, consider working up a 3D model and have someone print it with a carbon fiber-impregnated resin like Onyx. A honeycomb infill of varying percentages would give a lot of control over the finished weight.

Granted, a sub-6g hammer for a tube that size is excellent as is so it would be hard to justify starting over with CAD but maybe it’s something to consider for other projects.

Thanks for the idea, I did consider this but worried about the lubricity (currently using UHMW which is one of the most superior plastics for self lubrication and low coefficient while retaining high abrasion resistance, this stuff is almost like a rock hard soap)

With the hours I put into widdling this hammer, I would prefer a 3d printed design if theres a 3d printable filament that compares to uhmw.

I could skeletonize the current design and shave a tad more, but going from 6.6 to 5.2 grams, the valve doesn't even notice, only my ego, you'd think going from 10 to 5 grams would be night and day, it really isn't, it's comparable to going from 50 gram to 45 gram imo vs 50 to 25.

-Matt

 

[Stubbers]

	Hammer weight (gr)	Hammer Spring lbs/in	Hammer Locktime (ms)	Hammer Momentum	Hammer FPE
Standard Valve 58 gr .86"hammer travel	58	7.7	7.5	2.186	.582
Balanced Valve 25 gr w/ .125 stem closing force .86" hammer travel	25	7.7	5.23	1.361	.523
Balanced valve 5.2 gr w/ .061 stem closing force .53" hammer travel	5.2	3 w/ .45" preload 5 w/ no preload	1.93	.3	.123

Updated as I have made minor changes to hammer weight and travel, the above is what it takes to plateau (for me that is about 62 fpe in 25 cal shooting 34 gr)

 

[csdilligaf]

I dug around and found some balanced valves I did back in 2014 for Theoben based airguns. The stock hammers are like 76 grams and the valves are .312" diameter so these really helped. I'm getting back into tinkering around and this is going to be in my first build.

 

[markT]

Just found this thread. Very interesting to say the least.

 

[Stubbers]

I dug around and found some balanced valves I did back in 2014 for Theoben based airguns. The stock hammers are like 76 grams and the valves are .312" diameter so these really helped. I'm getting back into tinkering around and this is going to be in my first build.

View attachment 382458

Nice looking machining!

It is quite amazing how much dramatically reducing the valve load on a gun can really change how it feels. I've dabbled a lot with trying to minimize valve load on conventional valves, but there are many more doors to open up that allow one to operate pcp valves with very little effort, I feel like I can flick my current valve open with my finger, yet its very safe and doesn't discharge if banged around or dropped on the butt stock.

I used to think a (relatively high) safe minimum load was needed on a pcp's valve, while I still do that number has gone down tremendously as I started testing valves with very little load on them, even less then I've outlined here in this thread.

I think ~30 lbs of holding force suffices to be frank, possibly even 20

-Matt