Scott, a question.... If you make your poppet from PEEK, with the balance cylinder part of it and the piston fixed (or sliding) attached to the front cage.... how thick do you need to make the wall of the PEEK cylinder so that it doesn't collapse from the pressure inside the valve when the pressure inside is atmospheric?.... I plan to run the numbers, but I would like to know what you have been using for a wall thickness, and at what pressures?....Bob
Toot toot!There, I did it for you, lol. Very interesting. I’m always curious what is exactly going on inside these critters. I’ve been playing with my oscilloscope and pressure sensors some, trying to fine tune my pilot valve. Baby steps for sure. Thanks for sharing. Dave
I have to say, you must have had some determination to do that by hand. Glad you got it sealing proper. Dave
Hard as these valves close, can't see that thin stem area holding up
Quote from: Motorhead on April 04, 2023, 04:47:04 PMHard as these valves close, can't see that thin stem area holding up What is it about a balanced valve that makes it close hard?My thoughts are that it offers no extra closing force than a standard poppet.And a significant amount comes from the larger stem diameter pushing back on the hammer. The rest of the closing force comes from spring and sail effect. Dave
I was able to achieve a seal that held 100% overnight and passed a water dunk, so, here is my official toot I suppose.Below is my hand made balance piston, poppet and stem. The cage was made from a bolt head cut off, crudely rounded, reduced in height, and then tapped 6-32. This arrangement simply fits into the stock marauder valve with the only mod(s) required being reducing the end cap overall length by .1"~ and drilling the spring pocket a tad deeper, otherwise just a drop in to the stock valve. Tolerances were tight but manageable with room to spare. My balance chamber height is adjustable, as I did take it down to .155" from .175" while fixing the leak, (could go further but won't for now), can't give credit to anyone as I had the idea conceived at the time I made the spread sheet that calculates balance valve fill times, a few years ago, what can I say except great minds think alike. (Anyone casting shade on the thinned stem, I ran the same style stem in a non-balanced valve for 3 years without fail )I reduced the hammer to 27 grams and hammer gap to .045 (was 30 gr and .04 before I tore down), fps dropped from 890-900 to 860-870 on a 7 lb spring with barely any preload. Still need to run the valve thru its paces, test for break out friction, and make sure it is reliable from shot to shot, but so far I am impressed overall with the performance, and how much I've been able to reduce hammer weight, I could see going to 10-20 grams on this valve, even in 25 cal doing 60+ FPE. Maybe in time.. as I intend to do a .177/.22 cal upper that will absolutely require a lighter hammer if I only change caliber and hammer spring...-Matt