Motor and or trigger issues CA m4

Kevin_Dunne

My friend had a problem with his classic army m4 where it would only shoot sometimes but make some noise the others. I thought it was the trigger contacts and I cleaned them. They were a bit dirty but nothing major and then I reassembled the gearbox and the spring was going back a bit at a time with each press of the trigger or not at all. I reopend the gearbox double checked everything and it all looked fine. I then tested again and it fired fine but only if I held the the motor manually with my thumb in place but not when the motor was closed up. The motor contacts were in place btw

S.E.A.L.s

Sounds like it could be as simple as tighting up the motor adjustment screw on the base plate of the grip, if the screw is still in place and you should see a small hole or it could be a larger head on the base plate of the grip

In any case, have your AEG fully reassembled, with battery connected, tools ready and find the motor adjustment screw, then start turning the screw to find that sweet spot, once your AEG is firing as normal, your done

Please keep in mind this is trial and error, also, you may damage parts if the adjustment is off and you will be able to hear if its firing as normal or not

Hope this helps

T4RGET

Like SEALs said this is trial and error and can damage some parts.

So if you want to do it the long way and shim your gearbox in the process you can try this:

-Disassemble the GB again, then take out everything, I mean everything (watch the little spring on the outside of the 'box sitting in the selector plate )
-Now, take the right half of the gear box and place it flat on the table
-Put just the bevel gear into the gearbox (with the right half of the GB this gear should be facing with the grooves of the teeth towards you; i.e upwards)
-Next get your pistol grip and attach it to the base of the gearbox, put the motor in it and put the base plate and screws back
-now from here, because you only have half your gearbox, you can see everything in the gearbox.
-from here you just adjust the motor height, like SEALs said using the screw in the base plate until the pinion gear on the motor and the bevel gear mesh perfectly
-don't adjust it too high as it will push the bevel gear upwards due to the angle and although this isn't a problem when you only have half the GB, when you place the other half back and put the motor back in this same force wants to push the bevel gear upwards causing massive strain on the internals.

Hope it helps, it takes a while and may require you have some shims ready etc.

But it means a perfect fit between the bottom gear and the motor

Kevin_Dunne

T4RGET wrote: »

Like SEALs said this is trial and error and can damage some parts.

So if you want to do it the long way and shim your gearbox in the process you can try this:

-Disassemble the GB again, then take out everything, I mean everything (watch the little spring on the outside of the 'box sitting in the selector plate )
-Now, take the right half of the gear box and place it flat on the table
-Put just the bevel gear into the gearbox (with the right half of the GB this gear should be facing with the grooves of the teeth towards you; i.e upwards)
-Next get your pistol grip and attach it to the base of the gearbox, put the motor in it and put the base plate and screws back
-now from here, because you only have half your gearbox, you can see everything in the gearbox.
-from here you just adjust the motor height, like SEALs said using the screw in the base plate until the pinion gear on the motor and the bevel gear mesh perfectly
-don't adjust it too high as it will push the bevel gear upwards due to the angle and although this isn't a problem when you only have half the GB, when you place the other half back and put the motor back in this same force wants to push the bevel gear upwards causing massive strain on the internals.

Hope it helps, it takes a while and may require you have some shims ready etc.

But it means a perfect fit between the bottom gear and the motor

Thanks seals and target I tried adjusting the motor height last night and sometimes the gun just didn't even move I'll do what youbsiad but is it possible that the wires are getting pinched when I'm tightening it. Also I only have an 8.4 to test with I think I higher voltage might help. I've taken m4's apart so many times now and never had this problem

T4RGET

That sounds very odd. It may be that when the base plate of the grip is put back on the motor gets pushed down and so it disengages the connectors to the motor but you'd notice that when you removed the base plate.

have you tested the motor out of the gearbox?

Kevin_Dunne

T4RGET wrote: »

That sounds very odd. It may be that when the base plate of the grip is put back on the motor gets pushed down and so it disengages the connectors to the motor but you'd notice that when you removed the base plate.

have you tested the motor out of the gearbox?

Yep I took it out left the connectors on and the motor spun fine. Is it possible that this is an electrical issue? And I'm about to adjust the height and all now so I'll let you know if that works.

T4RGET

Kevin_Dunne wrote: »

Yep I took it out left the connectors on and the motor spun fine. Is it possible that this is an electrical issue? And I'm about to adjust the height and all now so I'll let you know if that works.

could be, but if the motor is spinning without problems out of the gearbox everytime the trigger is pulled then I duobt it like.

Let me know how it goes. Try a different grip if you have one. More specifically a different base plate. It's hard to identify small things like this without having the rifle infront of me. feeding issues could be causes by hop up or tappet plate, usually but something like this I'd have to go digging

S.E.A.L.s

Once you're happy that your AEG is assembled correctly, as you said, try another battery (9.6v or a min 20c Li-Po) and retest

If the issue is still ongoing, your AEG may require a lube on all moving parts or to be rewired, as a cable could be damaged and it may not be obvious how

S.E.A.L.s

T4RGET wrote: »

could be, but if the motor is spinning without problems out of the gearbox everytime the trigger is pulled then I duobt it like.

Let me know how it goes. Try a different grip if you have one. More specifically a different base plate. It's hard to identify small things like this without having the rifle infront of me. feeding issues could be causes by hop up or tappet plate, usually but something like this I'd have to go digging

This is another good suggestion and simple to check too

Kevin_Dunne

T4RGET wrote: »

could be, but if the motor is spinning without problems out of the gearbox everytime the trigger is pulled then I duobt it like.

Let me know how it goes. Try a different grip if you have one. More specifically a different base plate. It's hard to identify small things like this without having the rifle infront of me. feeding issues could be causes by hop up or tappet plate, usually but something like this I'd have to go digging

Hi tried the motor adjustment made no difference and I noticed that the motor and wires and getting very warm very fast. Suggestions?

DeBurca

Something in the gearbox is sticking/binding and the motor is drawing extra current which is causing the wiring to overheat trying to overcome whatever is causing this

T4RGET

Kevin_Dunne wrote: »

Hi tried the motor adjustment made no difference and I noticed that the motor and wires and getting very warm very fast. Suggestions?

No idea then sorry mate..

DeBurca wrote: »

Something in the gearbox is sticking/binding and the motor is drawing extra current which is causing the wiring to overheat trying to overcome whatever is causing this

Take it away DeBurca

Kevin_Dunne

DeBurca wrote: »

Something in the gearbox is sticking/binding and the motor is drawing extra current which is causing the wiring to overheat trying to overcome whatever is causing this

Any idea what this could be and by the way the motor can pull the spring back all the way only in stages but it cycles it fully sometimes. Could it be the antireversal and the bevel because I had trouble getting them in. Or is spring related thanks BTW DeBurca I'll try it tomorrow

DeBurca

No it is not your anti-reversal latch if you had it in incorrectly then it would prevent the gears from turning
With the piston in the forward position insert a long thin rod or screw driver through the the air-nozzle and push the piston back and let it come forward again do this several and you should be able to feel if there is any resistance to the smooth movement of it

Where all the existing shims refitted the same as when you originally opened it as a shim may have drop loose and be binding in the gears
Anyway it looks like you will need to open it up for a look see

Kevin_Dunne

DeBurca wrote: »

No it is not your anti-reversal latch if you had it in incorrectly then it would prevent the gears from turning
With the piston in the forward position insert a long thin rod or screw driver through the the air-nozzle and push the piston back and let it come forward again do this several and you should be able to feel if there is any resistance to the smooth movement of it

Where all the existing shims refitted the same as when you originally opened it as a shim may have drop loose and be binding in the gears
Anyway it looks like you will need to open it up for a look see

I actually have done the screwdriver trick every time I opened it and while hard to push back it went back fine and I don't think its a shim stuck anywhere but I will check

Kevin_Dunne

DeBurca wrote: »

No it is not your anti-reversal latch if you had it in incorrectly then it would prevent the gears from turning
With the piston in the forward position insert a long thin rod or screw driver through the the air-nozzle and push the piston back and let it come forward again do this several and you should be able to feel if there is any resistance to the smooth movement of it

Where all the existing shims refitted the same as when you originally opened it as a shim may have drop loose and be binding in the gears
Anyway it looks like you will need to open it up for a look see

Thanks to the guys who helped with the and DeBurca it was a shim that caused the problem I got rid of it and now have to reshim it and the anti reversal broke unfortunately so that needs replacing but thanks a lot