Lonex/KA gearbox compatibility with G&P receiver

[Rabbit]

Alright - so first off - both gear boxes fit in the g&p receiver just fine - pins line up etc.

The minute the grip is put on and motor inserted with end plate - firing the gun will cause it to lock up and not function. I kind of get half of a cycle, then dead. Pulling the trigger causes no motor wind at this point in semi or full, as if its an electrial error.

At this point once the grip is taken off along with the motor the gearbox seems to function again and have electrical function once again (tested by running the motor outside of the grip)

Both gear boxes were taken out of the g&p receiver and inserted into a king arms receiver to which they fuctioned just fine when fully assembled.

The original g&p gearbox functions fine when inserted into the g&p receiver and assembled.

Comparing each gear box on the outside (assuming this is where the problem lays) the only differences I saw were in the selector plate - minor ones at that, small cuts on the ass end of the selector plate and the copper piece at the front removed

I mimicked both of these details on the lonex selector plate to no avail when given a trial run.

Any ideas?

[lurkingknight]

how does it sound when you pull the trigger on the lonex assembled box?

what grip is it?


the piston not completing a cycle is generally a sign of bad shim/mesh... it could just be locking up because the motor pinion isn't meeting the bevel very well and forcing a misalignment. Even if the gears are nicely shimmed in the lonex box, it may not be nicely shimmed to your pinion gear shape or your motor.

If you have a MOE grip pts or clone, the baseplate sometimes forces the motor too high It doesn't fit the end bell of the motors well and it sits high or is misaligned.

the stealths might be able to shed more on anything more lonex gearbox specific.

[Rusty Lugnuts]

when you install the pistol grip end plate- be sure no wires are crossing over the motor, causing the motor to be too high into the mechbox

[Rabbit]

@lurking - genuine magpul moe grip is what I'm using - however I swapped to the stock grip that came with the aeg - resulted in the same above issues.

@rusty - funny you say that - my positive wire is overlapping.

The strange part is both the lonex and king arms gearbox's function fully in the king arms receiver with the same moe grip and overlapping positive wire.

One the swap is made with both gearboxes into the g&p receiver the above issues happen.

Perhaps different tolerances? The issue doesn't seem to be with any of the gearboxes - however something happens when they're inserted in the g&p receiver

Startin' to make me sweat and shit! I hate sweatin' while im at my work bench!

[Rabbit]

So after some trouble shooting this morning, I've determined that when I put the pistol grip on with the screws that hold it in, it some how misaligns the gearbox so that it will not fire.

I found this out by doing a big no no - hooking up the motor and holding it by hand pushing it into the gearbox - thing is, it fired just fine in semi/full auto.

Upon assembling the pistol grip with screws and doing things properly - I can fire one shot off in semi - then it proceeds to lock up.

Side note, bottom plate of the moe grip has been adjusted and overlapping of the wires have been rectified so they do not.

Thoughts?

[lurkingknight]

check for this? Airsoft motor misalignment fix part1 : m4 style grip & gearbox to receiver alignment - YouTube

[Stealth]

Briefly skimmed thread.

MOE grip motor screw hole is too small. It doesn't allow the motor end cap to sit inside it, so you're pushing the motor too far in. Test it out and see if that's your issue.

Solution: Enlarge the hole by milling out the screw threads with a dremel grinder bit. 2mm deep should do.

John

[Rabbit]

Yup - motor is more than likely being pushed too far in

I'm confused by what screw holes to mill out 2mm? The ones that hold the grip on to the gearbox? Or the end cap threads it self

It seems the end of the motor goes into the end cap just fine with assembling the grip while its not on the body with the motor inside of it.

[Stealth]

Remove the motor height screw completely. Test fit the plate over the motor end cap. The end cap should sit inside the big hole. However, the brass threads actually prevent the end cap from sitting inside. Just remove the threads to effectively enlarge the hole.

Another issue, depending on how you shimmed the bevel, is that the MOE grip interferes with the bushing hole for the bevel. Deepen the grooves to make sure the bevel axle can protrude fully out.

John

[Rabbit]

I noticed something last night - there is a noticible audio change when simply flipping the gun from safe - to semi - to full auto while the gearbox is inserted and pins and grips are in/on.

Almost as if something is slightly grinding or rubbing - I noticed the change is noise is there 100% of the time when the aeg ceases.

I took a dremel to the end plate - still feels like the motor is in too far - for shits and giggles I built up some electrical tape on the bottom of the gearbox where the grip is screwed on - this actually changed things a bit - I was able to pop off some semi shots with a slight trigger pull (not fully pulling it back) although again flipping it to full auto would ceased it all once again - even the electricity to the motor stops.

[Stealth]

You can test out your theory by not installing the motor adjustment plate at all, and simply using your finger to maintain pressure on the motor. Cycle the gun.