Building a 76rps gun

[Skywalker]

Trying to caution me is pretty much useless The best way to learn is to just do it I say.

It sounds like something might have been wrong with that gun, people have easily achieved 40+rps. And true tech-a-haulics have built guns closer to 80rps.

The only reason I'd agree that the gun would be rendered useless is the lack of ammo and mags that feed fast enough.

You have to be shooting a 6mm .20 gram BB pretty darn fast for it to create any significant pocket of air behind it. Maybe he had a volume issue, I'm not really sure without seeing the gun

Now, that doesn't mean there is a zero% chance of me having similar issues. And I've never actually played paintball so that statement doesn't really help me lol.

[Dominum]

The issue Gabe is referencing is a very real one, however I have only ever seen it in medium barrel length guns. A higher FPS and shorter barrel should remedy the problem if it presents itself.

[Skywalker]

here is a nice ghetto layout of the build. all and any input wanted, even if it might only add .05rps

[Dominum]

Needs moar C, go with a 30C IMO. Custom wire it entirely with as heavy silver wire as you can fit in the GB. You are using the 1" spacer with that 110 right? Definitely mod the boxmag to feed faster. Use the largest ball bearing bushings possible. The motor and gears all need to be perfected shimmed as a lack of surface area on teeth can be instantly disastrous, so spend a lot of time on that. If the motor is a little low or the bevel a little high you will not have a pinion in about 2 seconds.

[Skywalker]

Update on this crap....

I was running the set up today off of a 14.8v 35c lipo. Pretty killer, but hard to tell the difference from an 11.1.

Still having issues with loss of FPS on full auto, like the tappet plate isn't pulling forward and sealing the air nozzle before the gun fires. Semi auto seems to work fine. My tappet plate spring modifications may not have been good enough, or, the combination of the high speed ratio gearset, a g&p m170 motor, and 14.8 lipo might just be spinning too darn fast. Also the motor is heating up really really quickly. But at least I have a mosfet installed now lol. Not to mention sorbo, correct AOE, poly piston head.... This piston is on its way out though. At least I ordered 2... but until I get everything right, I'll probably just keep churning through them.

I continue to wish I had ordered the standard ratio gearset, which would put a lot less stress on my motor, and might spin slightly slow enough for the air nozzle to seal.... ugh.... I might just do that and find some other use for this high speed set.

Any input from the couple of you who know what I'm talking about is appreciated.

[Star_folder]

Do you have an after market nozzle? If it's not sealing with your hop up in full auto, you may try getting a slightly longer air nozzle and slowly file it down until the bbs feed. That may solve your compression issues. But it would be a little difficult to make sure it's filed down completely straight.

[Star_folder]

Here's another idea, what if it is your tappet plate spring? It may not be strong enough to pull your tappet plate forward fast enough before the sector gear grabs it again on full auto. The problem would be moot on semi auto because the gears would stop before it grabs the tappet plate again.

[Skywalker]

Yeah, I had cut down the tappet plate spring slightly, to make it stronger, and hopfully pull the air nozzle closed in time. But so far, no luck. Might go to lowes or home depot and see what they have, there might be a spring that could work.

But thats what I mean; since its a dual sector, there are 2 nubs on it instead of 1. Then factor in the 14.0? gear ratio, the m170 motor running on a 14.8v.... it might be almost impossible to get the tappet plate to pull forward in time. And I'm worried that If I make the spring too strong I'll just break the tappet plate.

Its not an after market air nozzle, but because its a Scar, I think its pretty much the longest air nozzle out there. I could be wrong, but I've yet to see a gun with a longer air nozzle.

[Star_folder]

Well, is your compression still fine if you are using an 11.1v lipo?

[Skywalker]

No, I've never had the gun firing correctly on full auto.

And a 7.4 20c nor 11.1 12c will cycle the gun.

I'm considering doing an electronic speed controller, like what people use in rc cars. But that isn't fixing the real issue. I need to go on airsoft mechanics and read the whole thread about dual sector and issues, see if other people have run into this with the high speed gearset.

[Dominum]

Unless you get a Sopmod airnozzle then you are right skywalker. Even if you did get a longer one and file it down, you'd be left with on the same length as the one you have now because if you left it any longer it would not leave enough room for the BB to clear it prior to being pushed forward, so that is a no go. I would do one of a few things; either use a slower motor, a smaller battery, or a rheostat. The last is really the best option because you can slowly and systematically dial it down slower and slower RPS until you reach the point with the highest RPS that still gives you proper FPS in full auto. This would be preferable to buying the other gear set IMO. Now, since I have never seen the issue you are referencing I am not about to speculate a fix on it that will allow you to use the same ROF without a loss of FPS in full auto. I will ask, are you using a #4 cylinder?

[Skywalker]

Its a full sealed type0.

Yeah I haven't decided if I want to try and slow the motor down... or buy the other gearset lol.

I was thinking... I want an Aug style pressure sensative trigger... that controls my ROF. ... Sounds like a challenge to me!

[Dominum]

Well, AUG triggers aren't pressure sensitive they just have two stages, once you pass a certain point it no longer applies the cutoff. What you are talking about could certainly be done if you just wire in a rheostat with a slide instead of a dial. How you would make it fit I do not know LOL.

[Skywalker]

imagine every cuss word in a row. thats what my mind is saying right now.

The issue the whole time has actually been because of compression, just somehow on semi auto it managed to shoot fine. IDK. But I noticed an air leak around the cylinder head/airnozzle. and once I re-sealed it, all of my shots are going at full fps. now, bbs aren't feeding the whole time, and i did even notice one or 2 bump in to each other in flight.

so anyway.. gunna hit up audacity here in a few and let you know what i'm clocking in at

[Skywalker]

Can somebody tell me what they count here, I'm having trouble figuring out which lines mean a shot. Am I correct in counting 38 in this image? or is it really half of that?