DBoys M4 gearbox

Fuzzytrooper

The piston in my gearbox won't fully cycle i.e. it won't fully move back. I've set up the shims according to the diagram that was posted in another thread and the gears seem to move ok without the piston-spring assembly. Any ideas or suggestions?

kdouglas

So is the piston just getting jammed halfway back and then stopping? How do you get it to move forward again? Open the gearbox and re-assemble?

Silly question, but is your battery fully charged?

Is the piston sitting correctly on it's rails?

Are the rails on the piston and on the inside of the gearbox smooth, clean and free from debris? I had a piston before which had an absolutely tiny bump on the inside of one of the rails, couldn't even see it by eye, but it caused the piston to jam constantly.

Stercus Accidit

Have you added a bearing spring guide or any other extra part that takes up internal space? Or a more powerful spring?

Its more likely one of KDs answers, I'd charge the battery and try again.

Fuzzytrooper

Nope I haven't changed the spring or anything like that. I'll have a look tonight at the piston an see what I can see. Cheers lads

Fuzzytrooper

Still won't work. I can't see any damage to the piston. The battery I tested with is fine. I've followed the guide on mechbox but still no joy.

chalky

Same thing happened to a friends dboys M4. After countless times opening up the gearbox, turns out all it needed was a bit of grease on the piston.

kdouglas

chalky wrote: »

Same thing happened to a friends dboys M4. After countless times opening up the gearbox, turns out all it needed was a bit of grease on the piston.

indeed, grease can help

Masada

Yeah try grease., if the grease dont work then try it with a few of the shims removed. it could be that there binding the gears. when your shimming the gears always test them with the cylinder removed and the box screwed back together tightly. some people assemble it and spin the gears while clamping the gearbox in their hand, the gears can be nice and free but can bond when the screws are back in.,

Doomofman

Dboys internals seem to be pretty rubbish... my semi fire didn't work out of the box... you get what you pay for I guess

Masada

there not bad actually, ive seen a lot worse.,

Harekin

Doomofman wrote: »

Dboys internals seem to be pretty rubbish... my semi fire didn't work out of the box... you get what you pay for I guess

DBoys internals are actually quite good, my S-System when I took it apart I noticed is really nice. Fully metal gearbox, gears, etc barring the bushings...in a stock €300-400 AEG you probably wouldnt get that.

The only complaint I have about DBoys guns is that they generally need everything tighened up when you buy them, nuts, bolts, etc...which in fairness isnt that bad!

Doomofman

Harekin wrote: »

DBoys internals are actually quite good, my S-System when I took it apart I noticed is really nice. Fully metal gearbox, gears, etc barring the bushings...in a stock €300-400 AEG you probably wouldnt get that.

The only complaint I have about DBoys guns is that they generally need everything tighened up when you buy them, nuts, bolts, etc...which in fairness isnt that bad!

It is for me.. I wouldnt have a clue how to do that

Harekin

You just tighten everything you can find...also, if you dont know how to tighten a few bolts, is it not a bit harsh for you to be labelling them as rubbish? If it was faulty outta the box you should've returned it.

Masada

Harekin wrote: »

if you dont know how to tighten a few bolts, is it not a bit harsh for you to be labelling them as rubbish?

yup my thoughts exactly.,lol

Doomofman

Harekin wrote: »

You just tighten everything you can find...also, if you dont know how to tighten a few bolts, is it not a bit harsh for you to be labelling them as rubbish? If it was faulty outta the box you should've returned it.

It was faulty to the point where it was annoying but still half worked... TBH it should have worked out of the box.. thats why it annoys me cause I wouldnt know how to fix it... but I'm not using it at the moment anyway.. I've used some of the externals and stuck em on my CA M15... so the dboys is just a backup anyway...

My point is.. It should really work out of the box.. but I'm sure most of the problems are easily fixed by someone with a little technical now how... Sure half the stuff in this thread I dont understand.. I've be afraid to even open the gearbox to see the stuff you're actually talking about...

Masada

thats the big difference between buying clones and buying high ends though, thats why they cost a third of the price of CA, TM, G&G,ICS etc., giving them a good going over before ya use ut is pretty easy.,

Fuzzytrooper

OK previously the piston wouldn't move back at all. Since then I've taken out some extra wiring I put in to reach the stock. When I took that wiring out the piston moves all the way to the back but doesn't cycle forward. When I tested it I attached the pistol grip to the gearbox but none of it was in the receiver. Would this be causing my problem? Anyway I'll have a go with it all put together tonight and see.

Fuzzytrooper

Ok the M4 is now shooting but with really low power. The battery I tested with was just charged

Fuzzytrooper

One of the teeth on the sector gear seems a bit chewed up. Would this be the reason for my low fps?

Stercus Accidit

Is it the first or last tooth?

Can it actually grab the piston?

I have a spare sector gear I can send you out, a bad tooth would quickly fcuk up the piston.


Bar that, too much/any grease in the cylinder will drop fps.

Fuzzytrooper

Thanks I appreciate the offer but I already have one on the way from Tony. The chewed tooth is right in the middle. I gave the piston,rails and cylinder a bit of a clean but that didn't seem to do much. The piston is fully cycling. It fires bbs just incredibly slow and with barely any range