Please Help. Locked gearbox.

[Liamcella96]

Hi guys. I have received a V2 gearbox from a friend who left his RIF out of action for a while and when he returned the gun no longer fired.

 

I took the gearbox apart to take a look and the grease has solidified partially which I thought could be the issue.

 

I have completely stripped the gearbox, and cleaned all gears etc so no grease or grease build up at all, also cleaned piston etc and replace grease in necessary places.

 

When the gearbox is open, all of the gears move freely and are placed correctly. All wiring has also been tested and working as it ahould to power motor from the firing switch.

 

When I tried to fire the gearbox. I can hear the motor turning what must be about 1mm before it hits the 1st gear but then everything is just rock solid and the motor cannot turn the gears. The battery and connectors then get rather hot due to the motor being frozen.

 

I have tried the motor and tested it in another RIF and it is working perfectly. Does anybody have any idea why the gearbox has frozen?

 

I have also been able to turn the gears manually with a screwdriver and the piston and spring seems to be working correctly. I just don't know why the motor cannot make the gears turn.

 

[EDcase]

Could be anti-reversal latch not fitted correctly.

Or shimming may be too tight.

 

When you say you can turn the gears with a screwdriver, how far around can you turn them?

You should be able to slowly do a full fire cycle with some effort.

 

Open it up, take out the main spring, then put the gearbox back together and see if you can turn the gears to complete a full cycle.

 

Its worth checking the shimming while its open anyway.

 

Edited October 12, 2021 by EDcase

[Shamal]

Is it possible that the motor may have connections round wrong way and running backwards?

 

[Liamcella96]

37 minutes ago, EDcase said:

Could be anti-reversal latch not fitted correctly.

Or shimming may be too tight.

 

When you say you can turn the gears with a screwdriver, how far around can you turn them?

You should be able to slowly do a full fire cycle with some effort.

 

Open it up, take out the main spring, then put the gearbox back together and see if you can turn the gears to complete a full cycle.

 

Its worth checking the shimming while its open anyway.

 

Yeah I was able to do a full cycle. Even with the spring In there as well.

The anti reversal latch is also definitely in place because as I was turning the gear I was locking the gears after every so often and then when I pulled the latch up it reset the system as you would expect.

[colinjallen]

What power is the spring?  What motor is it?

 

Maybe open it up and check the shimming; if that is ok, reassemble it without the piston, spring and ARL and try running it with the motor.

 

I do wonder whether Shamal has sussed it; it does sound like it could be reversed polarity.

[EDcase]

1 hour ago, Shamal said:

Is it possible that the motor may have connections round wrong way and running backwards?

 

Yeah could be but should be easy to check connector colours going to motor.

 

Its sounding more like it could be a dying or underpowered battery.

 

Edited October 12, 2021 by EDcase