reactivity, on off assembly, and pressure

[hill160881]

So if you properly tune the on off pin and assembly, a reactive X-valve is possible with a standard HP tank.

Why is this not done instead of the ninja tank? A $8 pin is way cheaper than needing a tank you can only use on one marker.

Specs are on a rt on off with a Quad o-ring and a Pure energy tank with stock reg.

.725 normal
.720 slightly reactive
.715 reactive(the ultra light mag was set here when the video was made)
.710 very fun (now the ultra light mag is set here)
.698 leaks when trigger is held

If you try this you will need another pin as an extra one incase you go to far. Take it slow with a dremal and digital calipers. Try it in the marker every .002" once past .725" to assure you dont go to far and make it more reactive than you want. They are all slightly different.

As always, I take no responsibility for what others try based on what I do.

[Smoothice]

I would even suggest just using a hand file when getting down to the important tuning. Those dremels can take a lot off if you aren't real careful.

[Spider-TW]

Shorter pins certainly help, as do quad o-rings. Less friction and shorter travel make better use of the available force. There are a few reasons why pressure was/is preferred. One is that short pins make for short engagement of the sear on the bolt lip. This can lead to premature wear on both (like nibbling on the bolt lip).

I think the quad o-rings were considered to wear faster than the regular urethane o-rings, but considering our usual lube and maintenance habits and shipping costs, it's not much of a factor anymore.

Another is bottle regulators. The crossfire bottles were about the first ones that were fast enough to RT at low pressure. Even some of the adjustable bottles didn't work fast enough to do well. The rate of RT is also related to the input pressure; as you dial up a good adjustable reg, the rate of fire typically goes from around 12 bps up to about 21 bps.

With the new(er) bottle regs and lubes, you definitely have a point, but I would still keep an eye on the first problem. You can see it before it gets bad.

Which bottle reg are you using?

[hill160881]

Crosfire. The ones with the crome top and a colored round botom piece. They are the stock ones the bottles came with.
I see the point about the sear, and that can be mitigated a bit with a stiffer spring.

Also the higher input pressure drags the efficiency down even more. But i have not actually tested that theory.

[Spider-TW]

Also the higher input pressure drags the efficiency down even more. But i have not actually tested that theory.

I'll be interested in that. If you don't believe in significant dynamic losses, it should have no effect since the regulator maintains the chamber to the same pressure.

[leloup]

Isn't an emag pin already shorter?

[Justus]

Yes, I believe an Emag pin is .712. I dropped my on/off pin from .750 down to .728 (IIRC - actual specs made in another thread) using the gray grinding wheel and a battery-operated dremel. The battery-operated dremel doesn't have much power - I wouldn't recommend it for regular use except for something like this where fine tuning is needed. At .728 and using my NitroDuck iReg at 1000 psi I was getting quite a bit of reactivity. I'm wondering if using a Ninja or Crossfire tank set at 900 or 950 would give me the same results if the pin were shortened just a little more.

[hill160881]

Yes, I believe an Emag pin is .712. I dropped my on/off pin from .750 down to .728 (IIRC - actual specs made in another thread) using the gray grinding wheel and a battery-operated dremel. The battery-operated dremel doesn't have much power - I wouldn't recommend it for regular use except for something like this where fine tuning is needed. At .728 and using my NitroDuck iReg at 1000 psi I was getting quite a bit of reactivity. I'm wondering if using a Ninja or Crossfire tank set at 900 or 950 would give me the same results if the pin were shortened just a little more.

I would say that .715-.718 is the sweet spot I have found, for the X valve on the ultra light mag anyway. .710 tends to be a bit to happy but a blast to shoot at 30 bps at 900 psi

However some E-mag valves were designed with the side profile of the Quad o-ring in mind since they had them. So the stock length was .725 (.712 was the dual oring top) and if shortened to .718 they react really nice.

[hill160881]

I am also using Pure Energy tanks/regs with close to the same results.

[Spider-TW]

I would say that .715-.718 is the sweet spot I have found, for the X valve on the ultra light mag anyway. .710 tends to be a bit to happy but a blast to shoot at 30 bps at 900 psi

However some E-mag valves were designed with the side profile of the Quad o-ring in mind since they had them. So the stock length was .725 (.712 was the dual oring top) and if shortened to .718 they react really nice.

To add to that ^^^ ...

You just have to remember that a quad has the top and bottom seals to it. You have to clear the bottom to get any good flow. Since a regular o-ring seals in the middle of its .070 size (0.035 from the bottom), by going to a quad, you drop your seal down from that middle to almost the bottom which is about 0.025 inches. So a 0.725 pin with a quad is basically in the same place as a 0.750 pin with a stock urethane o-ring. A 0.750 pin with a quad will often starve a valve, or hardly open at all.

Keep in mind that your field strip screw travels 1/32" or 0.031(25)" per turn. Be consistent with that tension.

[sjrtk]

I run my x valve (in the Emag) with a .698 pin length an Quad O-ring. It reacts good nothing insane but good. My RT Pro valve on the other have has a .725 pin with the single O-ring top it also reacts again not crazy fast but more than fast enough for normal goofing off. Then there is Satan valve (ReTro now on punishment detail and speed ball duty too) she has a .728 pin and will burn through paint as fast as i can load it. I have to use a .740 or longer pin to keep it reasonable. All 3 of these valves run on the SAME TANK new Crossfire Stealth reg putting out 825.