v3 gearbox jamming issue
 

Hey guys,

I have been trying to troubleshoot a problem with a friends aeg for the last 2 weeks and I am officially stumped. The issue is this; the rifle will randomly jam after a few shots (no BBs in the gun, just dry firing). As soon as it jams it will remain in that state, but the second I pull the gearbox out of the handle casing, it fires perfectly.

The wiring looks good and I tested the trigger and voltage. The only thing that I can think to do is solder the motor wires directly to the tabs at this point and see if it's a connection issue there.

If anyone has experienced this before, I would love to hear your solution.

Gun is an H&K g36c with upgraded 40,000 rpm motor.

Thanks,

How is it jamming? gears locking up? is it making any wretched noises? Maybe check your motor height. Does it just stop moving completely?

While it jammed, do you hear a click when trigger is pulled?

When the gearbox stops functioning, does it lock up as in you get a click, or is there no electrical response whatsoever?

It's normal for v3 gearboxes. It means you need to A. full-auto to unjam, or B. Stop short stroking.

Alternative is to get a MOSFET or a high speed gear set and a high-torque motor combo so that you can have better trigger response.

Why it is a specific v3 gearbox issue is beyond me.

What battery are you using?

Hey every, I have diagnosed further and now I am completely confused. The gearbox fires perfectly, then I put it in the shell, and nothing. No clicks, no function what so ever. Then if I pull it halfway out of the shell, immediately functions perfectly.

The selector is in place, I soldered every connection to make sure nothing was getting loose, I heat shrunk every possible place where it could have been shorting or grounding. I have no idea at this point.

Resolder the wires closer to the motor. This is a common problem in V3 gearboxes where inserting the gearbox into the grip pulls wires, which pulls on the motor tabs and in turn affects the brush hoods.

Could you elaborate? What do you mean by "closer to the motor"? I have the wires soldered directly to both tabs, and it doesn't seem like they are being pulled when I put them into the grip. I even taped them down to the sides of the grip and greased the tape so it would slide in an out nicely, but still same issue persists.

Don't put tape and shit on the sides of the grip. The pistol grip is tight enough as it is without them.

When you put in the gearbox to the lower receiver, put the body pin in that connects it together. Turn it upside down. Look down the pistol grip. Are the wires getting caught on the motor? If so, adjust it.

Now you have 2 options: solder the connectors onto the motor OR leave it as it. Put the base plate on. Now take it off again. If the connectors are still intact and snug on the motor connector, don't touch anything. If it comes loose/falls off, solder it down.

Had a similar problem with a TM mp5 where the connectors come out after being rattled. Not sure if that is what's happening with you.

How hard is the shell jammed into the receiver? is the shell getting crushed enough to put enough torque on the gears to cause too much friction?

Solder the wires so that they are routed closer to the body of the motor and have a smaller chance of being tugged as the gearbox is inserted.

Also take a multimeter, remove the grip plate, cycle the gearbox. When the gearbox seizes, take the multimeter and confirm that there is no continuity between the motor poles to see if it is the issue I suspect it to be.

Thanks for all the response, will give all of this a try. I did get it in the shell and firing, but after 12 shots it cut out again. I will take the multi meter to it and see what it reads. And report back.

What Battery are you using?, I had a similar problem with a Ni–MH battery with one bad cell. Try a new or different one.