Valve recharge times....why's the RT so fast and other's arent?

[paintball8869]

I'm looking at working on a Rainmaker paintball gun. I'm getting it for next to nothing and most of the parts for free, so in the long run, it'll cost me roughly $150 total to do what i want to it.

Well i'm now looking at the valve. I've got parts that can cycle 40+ times per second and am trying to figure out how to speed up the internals of the RM (basically delrin inserts). So once I get that out of the way, which is only a matter of time, I'm going to need to figure out how to get the valve to recharge quicker. That way it won't only cycle extremely fast, but be able to shoot fast as well.

So my main question is, how can the RT recharge so fast, yet no other valves which seem to be higher flow to me can't recharge as fast? I would think that the RM valve, with teh air coming in through the back of the valve chamber, would be able to recharge fast. THe only thing i believe that owuld be slowing it down is the the cupseal having to open.

Anyone have any ideas here? I'm planning on lowering the pressure to the 250 range, putting in lighter springs, putting in a lighter hammer/carrier (delrin inserts with stainless steel). So it should move fast enough to recharge faster, but supposedly the only valve capable of handling the 25 bps range is the RT valve. Just trying to get another gun up in that range. Thanks.

[AGD]

Hammer valve guns like yours can recharge fast enough to shoot 25 bps but you might have to turn up the pressure. Its the other parts that have a tough time moving that fast.
AGD

[paintball8869]

thanks tom.....good to hear that it will at least be able to recharge quick enough for 25 bps. I'm hoping I can get it to fully cycle that fast (gotta lighten the hammer and such). The ram i have was going over 40 cps without pushing it, so that was pretty nice :)

[Redkey]

how were you measuring 40 cps on that ram? What solenoid were you using to drive it? What were you using to drive the solenoid?

[paintball8869]

i was up at Action Automation in MA. They had it hooked up at 60 psi off a compressor. We used an oscilloscope? I don't remember the exact thign they used. But it had settings to change voltages, frequencies, etc. It had a LCD screen on it showing peak performance of it along with the pressure.

We had the solenoid running at 10,000 cycles per minute by itself (nothing attached). We had the ram running off the solenoid and 60 psi, 6 volts, fully opening and closing, at 40+ cycles per second. Something around 4,000 per minute.

It was a MAC solenoid.......44B-AAA-GDSA-1BA

[hitech]

Originally posted by paintball8869
I'm planning on lowering the pressure to the 250 range...

Everything else being equal, I would think that the higher the pressure, therefore the lower the volume, the faster the rechare rate. Is my thinking wrong?

[Magluvr]

Originally posted by hitech


Everything else being equal, I would think that the higher the pressure, therefore the lower the volume, the faster the rechare rate. Is my thinking wrong?

I agree with hitech, if you want the gun to be able to recharge itslef fast enough you will HAVE to run high pressure, or if you are dead set on low pressure you will have to have EXTREMELY good flow. So I would say to try and stay as high pressure as you possibly can and then make sure you have high enough flow.
(Note: Tom Kaye seems to be on our side, he said basically the same thing!)

[Wat]

The automags have a dump chamber type design. A chamber of fixed volume is filled with gas to pressure X. Then the gas is dumped to propel the ball.

The RT valve recharges much faster than the standard mag valve because of the way dump chamber is filled. Lets say the operating pressure is 400psi and the input pressure is 800psi. In the old level 7 mag, the 800psi upstream gas is regulated down to 400psi, then used to fill the chamber. In the RT valve, the full pressure 800psi upstream gas is used to fill the chamber and then the on/off valve is switched closed once the chamber reaches 400psi.

The RT recharges faster because the chamber is being filled with higher pressure gas. The advantages of the RT valve diminish as input pressure decreases. The closer to 400psi you feed an RT valve, the closer to standard mag like performance you will get.

Hammer valve guns have a restriction on the inherent dwell time on the valve. For the most part, higher cycling speeds will reduce dwell time. To get enough gas through the valve in a shorter period of time to propell the ball without shootdown you'll need to up the pressure.

[Magluvr]

It sounds to me as if the RetroValve basically transforms the "valve, reg and dump chamber" into just a reg. (Basically, an extremely "overbored" reg with the "regulated side" being the dump chamber.

[athomas]

In the RT valve, the regulator essentially controls the on/off (not the on/off pin) of the air flow into the front chamber. The actual flow of air into the chamber is pushed by ~800psi from the source. The high pressure differential between an ~800psi source and an ~50psi empty chamber allows for fast recharge times.

If you want the rainmaker to charge quickly then you want a pretty good flow path into the chamber. A higher presure would force the air in faster. If you want the gun to operate on a lower pressure then you need a high volume low pressure regulator and you need to open the air passages in the gun.

[AzrealDarkmoonZ]

Getting the rainmaker to cycle at even 13 bps will take some custom hammer work. Not sure if you could get it to 20, it would take a monumental amount of work. The Rainmakers design just does not lend itself to speed.

Az

[nerobro]

Originally posted by AzrealDarkmoonZ
Getting the rainmaker to cycle at even 13 bps will take some custom hammer work.


Based on what data? The only thing limiting the gun off the bat has nothing whatsoever to do with the hammer. Saying the hammer is the problem on the rainmaker is like saying the bolt is the problem on an automag.


The Rainmakers design just does not lend itself to speed.


the rainmaker has a relitively light carrier, bolt, and hammer. Rams can easily huall that mass just about as fast as you can please.

The limiting factors I can see are the board, which is easily replaced, the LPR, which is of unknown quality and design, and given the gun is cappable of stopping on a paintball, is probally set far to low to get automag type rates of fire.

The stock ram is of large diameter and shouldn't pose a problem. Solinoids.. at least from the MFG data I've seen, shouldn't pose a problem for any gun.. of any make.

Basicly, the rainmaker is as fine a gun as a cocker, a mag, a spyder, or any other gun to make into a high rof monster.