I am considering something like this. Thank you for sharing your work here. I do have a couple of questions. What solenoid are you using that is strong enough to knock open the valve. With such a low duty cycle, I would suspect it could be overdriven from rated voltage. What does the time open (dwell) need to be? I’m aware this is relative to several things, just wondering a range. Microseconds? Milliseconds?I was thinking of using an Arduino to fire a mosfet for an adjustable (by pot) amount of time. I wrote a sketch for it but was wondering what time window I needed to map the pot output for. Thanks again,Dave
The arduino can work in the single digit useconds. I had considered a capacitor discharge similar to yours but I have most of the components for the arduino setup. I had to order the boost converter. Either way should work the same so long as supply is regulated. I am going to have to get a regulator setup. Without regulator, my way should drop fps with each shot.I know yours is regulated but if it wasn’t, I assume yours would have the ability to ‘balance’ so to speak, since as the pressure drops, dwell will increase due to the closing force lessening and cap is able to hold at lower voltage. Would be curious if one could ‘tune’ your system with a rheostat across the solenoid to speed discharge rate of a larger cap? Now I’m rambling. Thanks for the infoDave
FWIW ... I too have been tensioning barrels for a while now & found you don't need to be that elaborate. Tension tube must have very square ends against very square end cap and breech is all thats required.Threaded barrel at muzzle or a slip on threaded air stripper ( Epoxied on or Sleeve retainer ) with the end tap being hand tensioned to only modest compression has been rock sold and trouble free.Shroud tube best being steel, but aluminum is working too w/o issue.JMO tho finding K.I.S.S. works just fine.Scott S
I would highly recommend the Bellevilles if the materials for the barrel and shroud don't have the same thermal coefficient of expansion.... For your barrel I would imagine you can use less tension.... Increase the tension until the groups tighten up, after that happens further tension usually does little....Bob