AEG sputtering on full auto?

[STUFAS]

Hi all I'm not the best tech in world "Hahaha this is how most threads start"

I have a issue with my latest build, on semi it's a beast. However on full auto it is NOT!. 

The problem is that the gun sputters and rounds exit the barrel but FAR from consistent, some short some mid range but none to it's full range. 

The gearbox consists of

Retro arms cnc split gearbox with integrated hop.

SHS piston/13:1 gears/cylinder head/tapper plate shortened fin.

AIR LAB Sorbothane pad (70D)

ASG ULTIMAT/ cylinder/aluminium piston head/air nozzle/30k motor/M105 spring. 

Jefftron Leviathan & 11.1v lipo's

So i think its about 30/35 rps so its quite pokei. 

I can calm down the rate of fire via the Leviathan to 99% and it will fire with no hiccups "but that's no fun" and it's just like a regular aeg.

So the only thing I've tried is to shorten the tappet plate fin but to no affect I was also going to shorten the tappet plate spring by a couple of loops but its quite strong already. 

Hopefully one of you bright sparks will know exactly what the problem is and help me out.

Cheers guys.

View attachment 44992

 

[johnnyj]

Nice gb have to ask what mags you using ? 

 

[STUFAS]

Ha ha I knew there was something I missed. 

Their CAA 140 mid caps.

Their good with pushing .3s into my KRYTAC and no problem on semi or full auto on both guns. 

 

[STUFAS]

Hahaha I knew there was something I missed. 

I use CAA 140rd Midcaps. 

Their good  feed .3s into my Krytac and my other gun no problem on semi & full auto. 

 

[johnnyj]

Ok 30rps is not super fast is the gear set delayed ? how long a barrel are you using and is it matched to the cylinder . have you SS'd it ? ( M130 should be putting silly FPS out ) whats its fps ? 

 

[STUFAS]

Ok so it’s a R-hoped 6.03 ss 363mm long with a modified promi purple bucking, the spring is a ASG 105 sorry I just looked at my original post “not 130” to compensate for the loss of cylinder volume due to the sorbo pad correcting the AOE.

and the cylinder is a type?????? Standard M4 type. The air seal is fantastic as being a split box you can put your thumb at the end off the barrel and compress the piston in the cylinder and it doesn’t budge. And the gear is delayed.

 

[ImTriggerHappy]

It can be several things. One your mags are not feeding in quick enough so the nozzle is catching the bb badly which can mean it centres badly so it's initial push is bad and the nub cant stabilise it. Other thing is same initial thing but it is distorting your feed lips as it all smacks together.

It could possibly be catching your piston early if it is slow returning. This will mean it does not complete the cycle and you will get the varying power of shots you are describing. That is where short stroking the piston comes into play.

It will have nothing to do with barrel and cylinder volume matching as although that will screw things up it would be consistent on it's results. 

Do not shave the fin on your tappet plate as that is actually the opposite of what you need.

These are all maybes as without the gun in hand it is all pure guesswork.

 

[STUFAS]

Thanks Happy. I'll put my RA tappet plate back in, examine the bucking lips and ask a mate for a few different mags to try. Don't think I'll shorten the stroke as that means I'll need a new piston & sector gear if it's not it. 

Cheers mate?

 

[ImTriggerHappy]

Thanks Happy. I'll put my RA tappet plate back in, examine the bucking lips and ask a mate for a few different mags to try. Don't think I'll shorten the stroke as that means I'll need a new piston & sector gear if it's not it. 

Cheers mate?

If it is catching early you will be able to tell by looking at the piston as it will be getting marked up.