Back to the AUG

Alright. That's what I needed to hear. That I have some hope of it working correctly without the original. I wonder why JG put that in there in the first place.. I'll let you know how it goes lol.
Btw, your profile pic has a sector gear with delay chip XD

 

Yes my original cylinder in my AUG was ported. That was the first thing to go. Ridiculous considering the gun is undervolumed even with a FULL cylinder due to the unnecessarily long inner barrel.

 

Ok well I got the gearbox back together (#!*&%ing trigger) and get this - it seems to be cycling well with only minimal overspin now. The nozzle is sometimes a little out of place after a shot but not badly and there is no double shot happening. Is it possible that the delay chip it originally had was causing the overspin? i noticed it is a lot tougher to pull the tappet plate back now but perhaps that is just because of the lower ratio gears.
I haven't test fired with bbs yet but I'm getting pretty snappy trigger response and absolutely no gear noise which is probably helped by this being probably the best shim job I've ever done. Absolutely no free play between bushings. Completely snug and perfectly meshed but still free spinning. Call me conceited but I'm proud of myself.
Thanks to everyone who has been a great help with this overspin issue. Crossing my fingers that it will feed ok when i get the gearbox back in. Hopefully the mechanical issues are done for now until get a trigger replacing mosfet. For now my next step on this build is to stabilize the outer barrel and the custom front rail/grip I added, which are both wobbling enough to annoy me. I'm pretty sure its JB Weld time.

 

Problem number 427:

I got everything back together, put a new set screw to stabilize the outer barrel, shimmed the wobbly grip with sheet metal. Everything feels super solid now.
Filled up a mag and test fired.
Semi auto: feels great, sounds great, probably is great.
Full auto: a laser beam stream of bbs for about 30 bbs then a scary grinding noise and no bbs.

Tried semi auto again. Grinding noise with each cycle and no bb.
Sighed heavily and went back to the workbench. Pulled the gearbox out and noticed 2 bbs fell out with it. Test fired the gearbox and it sounds fine.
I'm scratching my head. Is it possible that a bb somehow got wedged next to the nozzle or something?
*Edit* found a bb in the packing. Seemed wedged in there pretty good. Maybe a bad bb or the packing swelled from friction?
*Edit #2* put it all together again and test fired again. Few shots in semi great. 15 shots full auto and then grind. Opened it up, emptied the bb out, noticed there was another bb wedged in the packing. This time the bottom half of the packing lip was folded under the bb wedging it in Place. Is it possible that the high rof nozzle is pushing the bb into the packing before the mag has time to push the bb into place?

View attachment 169751 View attachment 169753

 

Hmmm, I found one of our old threads from 2018 where a few people were saying that tru-hop packing feed lips are too long. I looked thru the mag well and noticed that it sticks out a teeny bit into the feed tube. Prolly wasn't enough to be a problem before but that higher rps seems to cause problems when rubbing by it. Prolly doesn't have time to get back into position before another bb comes and folds it into the barrel. Guess I'm gonna have to throw my old flat hop back in which I've been meaning to do anyway since this tru-hop hasn't quite been able to match it in performance.

 

Yeah, I've heard both about Tru-hop packings. Since ive been out for over a year, are there any better options than tru-hop or flat hop with m nub? I dont think I have the patience to figure out how to do a quality r hop correctly.

 

I've used maple leaf but was never able to get as much consistency as with a flat hop. I do use the ML concave nub though.

 

Light blue ML (70 degree i think?)
The flat hop was done on a G&G green.
Both use the concave nub.

In other news i tried trimming 50% of the lips off the truhop packing but now I'm shooting at 130fps -.-
I'm thinking the nozzle isnt sealing now because of how soft truhop rubber is. It is probably blowing out around the lips now or ballooning up. Its possible that its something in the gearbox (I hope not) because I didn't chrono after getting the gearbox back together until now. However i only noticed today that the bbs were moving pretty slowly visually and i think i would have noticed that before now.

 

yeah, i went to 13:1 and it fixed the problem. i was already running a microfet mosfet so i didnt want to mess with titan. Autobraking is generally bad for the motor too so i was only looking at that as a last resort.

 

Ok, I went back to the ML packing and it fixed the compression issue. Now getting 336 fps with .30s right now which is a bit TOO solid. And that's without teflon taping the packing yet. lol
I should probably know this, but is it normal for bbs to roll out of the barrel when the hop up is off? I thought the lips of the packing stopped that. Am I wrong?
I tightened up the hop up and it doesn't seem to be doing it anymore but I'm still wondering. Im pretty sure this gun is cursed.
*edit* I just pulled the barrel and hopup out and yes, I am able to drop a bb straight through when the hop up is off. i compared lip diameter to the old G&G Green and the G&G definitely is smaller and loosely holds the bb. Guess I'm going to have to order another G&G Green packing (this one is really old and worn). I should have just done that anyway since that packing has given me more consistent results when flat hopped than any other set up has.

 

You know, I'll admit, I was super skeptical at first and assumed you were just another newbie trying to sound smart until I figured out what the heck you were talking about.
Honestly that might actually be a good option and im super intrigued now. I'll definitely try it the next time I have to open up the gb.
@Lefse -in case you still have your old AUG around and this ends up working.
From what i can tell, hes talking about the combine-plate that you have to slide off before opening up the gearbox. The only thing is I'd imagine that the trigger spring would still be hard to bend around the trigger with the box mostly closed. It's worth a shot though.