Can you Mech an Impulse?

[Rainmaker]

I did a decent amount of searching, but my google-fu is failing me. Has anyone done a mechanical conversion to an Impulse? Looking at the diagram, it looks like it would be a bit more involved than mech-ing an Ion. Any input much appreciated!

[Toestr]

It can be done. There is a guy who mech'd a timmy and the Impulse has the same concept of operation. I'm pretty sure it uses a series of valves to meter the timing of air going to the ram because this would be much more dwell sensitive than a typical mech Ion. Tbh the best way to mech a poppet is to make it a blowback.

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[Pumpytrilly1]

It would need a sandwich plate where the noid goes to be tapped for barbs. Might be interested in one if you get some made.

[Siress]

Hmm. In theory, you could avoid the dwell issue by allowing the higher force on the valve pin to seal the valve even while the ram is pressing on it. It'll make a farting noise as the air spring oscillates after the initial impact - and be very inefficient.

A mechanical 'dwell' for the actuation pressure is going to be tricky. My first thought is a fixed volume dump chamber and multi-stage actuation valve.

edit: This is crude, but I recall that there's a mechanical override button on one end of the solenoid. If your solenoid seals are good, you could just add linkage to press that button on trigger pull. I expect the aforementioned farting.

[scottieb]

Pffffffffft!

[Jonnydread]

sandwich plate

[XEMON]

Ive been thinking about it fr a while, but havnt gotten my hand on one yet.
My thought have been to used a pneumatic pulse valve to cycle the ram.

Do you have one ready to go?

[rawbutter]

I fiddled with pneumatic pulse valve designs a while back for pneumag application. I don't know of any out there that are commercially available and are small enough to fit inside a marker. (Not saying they don't exist, just that I've never found one.) The biggest problem with designing one is venting the pulse of air after it is used. You could use something like a MAC-43 solenoid valve, which has five ports. When the valve is at rest, it could direct some air into a volume chamber of some kind, and then when the valve is activated, it would dump that air into the ram to cycle that. But then where does that air go after that? There would be no way to reset the ram, and it would just stay forward. Right?

[JCC]

If anyone ever manages a good performing mech conversion for these style guns it would sell like crazy. In theory same kit would work on Impulse, Bushmaster, Angels, Timmys, and tons of others. Only thing that would change is the plate that replaces the solenoid with the LP hose barbs threaded to it. These guns are dependent on consistent dwell for velocity, which basically means you can not just swap the solenoid for a mech valve as your trigger finger will affect the velocity as how long you open the valve will vary and with that so will velocity. The fix for this would be a valve with some type of mechanical reset that ideally is adjust in a range of 5-40ms or so. Where it always provides that dwell even if the valve is held for 1ms or 1 whole second. A valve that performs that function in a form suitable for paintball is sadly non-existent. Someone builds one and they would sell like crazy though. Even if they were non-adjustable and you had to buy them in a set dwell value so depending on marker would have to buy different valve would still sell. If anyone knows an engineer at somewhere like Clippard or SMC, or even just has a contact in the industry that could provide a cost estimate per valve and initial run size required would love to know. Creating something like that should be right in their wheelhouse, but probably not cost effective for less then 10,000 units or so.

[Siress]

Wave spring assisted ram return to prevent farting with mech trigger valve. Solves the dwell issue entirely. It will still oscillate, but the intent is to keep the valve pin from being part of that oscillation so that it doesn't waste gas - and prevents the loud farting sound. The ram and wave spring may still oscillate creating a 'ting'-ing sound like a fast metal rattle. And this is only if you hold the trigger down - which keeps the ram held forward.

To be clear, this mechanism is not ideal... it will be difficult to find the right balance of wave spring and pressure settings.

[JCC]

This idea could keep ram/hammer from holding valve open, but would be very hard to find right balance. Also, this sets max dwell not minimum so a trigger pull that was shorter than required dwell would be a low velocity shot or a partial cycle even. Seems likely to be wildly inconsistent and chop paint from partial cycles if really on the trigger.

[Siress]

You just described short stroking. That has everything to do with the trigger group and nothing to do with the firing mechanics - unless they're integrated, which here they are not.

[JCC]

Short stroking would be if you do not pull the trigger fully and the valve is never fully opened. A setup like this you could pull the trigger fully, but pulled it so fast that the valve was not open long enough. Similar but different phenomenon the short stroking. End result is the same is you would end up with a situation where hammer would not open valve long enough so velocity would drop. Could be as bad as gun cycles, but does not fire then you end up with multiple balls in barrel before firing which is instant mess.