Gearbox seizure and selector lever problem.

[89db]

I am not too sure if it should be here or "Doctor's Corner" section but well...
First I searched and read : Semi-Auto Seizure Explained ( trigger glitch ) and I am fairly sure its not my problem. AND I fired the AEG just before disassemble it and it was working fine.

So, I bought a Spring to lower my FPS so I can comply to CQB rules.
While opening the the gears moved so I decided to realign everything following videos from mechbox.com. My gearbox is a V2 for an M4.

The only part I touched are:
The gears
The anti-reversal latch
The trigger (pop'd out when opened the gearbox)
Tappet plate + spring
And the whole Cylinder assemble (To put the new spring in)

Reassembled everything. Try to fire... the piston seems to seize (or isn't going all the way to the end) and needs another pull to to complete the cycle and fire.

Also the motor was slightly smelling after but since its my first airsoft I am not sure if its normal (and didnt noticed when test firing previously).

Now I am not too sure if my battery was dying or not but I dont think so. I also rewired to the rear and extended the wires but I double test the electric circuit and everything is working flawlessly.

Is it just wrong timing on the gears? maybe the timing moved while closing the gearbox
Is the motor isnt aligned properly in the gearbox?
Is a dying battery would do that?


Second, when I put the selector to SEMI, i have a resistance in my trigger, the plastic lever that blocks the trigger on safe seems to be holding the trigger. And with minimal force it slides and let me fire. when put to SAFE and AUTO its fine.

Here is a pics if you see something that my newbie eyes didn't


Thanks in advance for input, and sorry for the loooong post.

*** EDIT***

The AEG is fine now, was a problem with the motor height, it was adjusted too high. But I also shimmed properly my gear box while it was opened. Thanks for the support of the gun doctors.

[Styrak]

There's no such thing as "gear timing".

Is it shimmed properly? Did you move any shims on the gear axles? Did you test for gear movement before you put it back together?

[m102404]

Long post with decent information is far better than a short post that doesn't mean much

Since your gun actually cycles (2 trigger pulls or whatever)...it sounds like it could be 1 of 3 things...or a combination of them.

1. Your battery is not fully charged
- easy remedy...charge it up fully, use a known good battery, etc...

2. Your motor height is not set correctly
- adjust the screw in the center of your grip...all the way in, back it out a couple of turns and listend to the shot. When it's as quiet/smooth as it gets...that's the best you're going to get. When you get close...just make small adjustments
- you don't have to fully reassemble the gun to set this...you can put the mechbox together and screw the grip direction onto the mechbox. You should still fine tune it once the whole AEG is assembled though.

3. You messed up the shimming
- you may have put too many shims on a gear, essentially jamming/squeezing it too tight.....the only fix to that is to reshim it properly.
- you have to readjust the motor height after reshimming....maybe not by much though. See #2

* there is no such thing as timing...as long as the nub on the half gear (in your case it's more like a curved bar...on most it's more like a post) is in front of the tappet plate fin (white triangle piece positioned on the gear)....you're good to go.

[89db]

There was no shim when I opened it. But it seemed to be good, was moving freely.
When you mean there is no timing you mean its doesnt matter where the sector gear teeth are when I reassembly it? Maybe I didnt expressed my self properly please let me know what the correct terms are. Gear alignment?

***EDIT***
Thanks m102404, for the Timing clarification.

[m102404]

"gear timing" was used to describe a position of the sector/half gear and a lot of people misunderstood it to mean that your gears needed to be in a certain position or things weren't working right.

The position of the sector gear in your pic is perfect.
- the nub that rotates and moves the tappet fin is not contacting the fin
- the teeth of the half gear are not engaged in the piston
...that's all you need to think of when positioning the gear. The nub could be at the 1, 2, 3 o'clock positions...all the same result. But if it's in the 8-12 oclock positions then you're not going to be able to close your mechbox up 'cause the tappet fin will be laying ontop of the nub.

That's the sole reason behind saying "rotate your gear to the 1 oclock position".

It's always going to rotate freely without the mechbox being closed up. If you want to check your shimming you should probably research those threads more.

[Styrak]

Charge your battery.

[89db]

Thanks, I researched on Shimming, and I will again (normally I read 1000 articles before engaging the project to be sure I dont miss anything).

I was surprised that there was no shims in place (but no surprising since my gun is an entry level on, the gearbox is from a VA gun, its the black one with metal bushings and a M120 Spring)

So I'll call torontoairsoft see if they have shims in stock so I can do go pick them up.

and for the Trigger/Lever problem? did it happened to anybody? probably easy to fix, maybe when I ll reassemble my box it ll be fix.

***EDIT***

My battery is charged now but havn't retried... I reopened the box. Will retest once I shimmed it properly.

[m102404]

With the trigger pull being blocked a bit by the "safety" bar...don't sweat it. You'll notice a bit a variation as the parts wear, as the gun is reassembled, as screws are torqued to different tightnesses.

[89db]

Cool ! Thanks a lot, I will shim my gears and let you guys know if it fixed my issue.