Question on Gearbox.

DevilsBreath

Hi All

Having a problem with the gearbox in my CA G3.

I have so far managed to snap two piston's

All the gears are seated correctly.

I have noticed and believe this may be the problem.

When firing on full auto the piston can sometimes not go fully forward again and be held in place by the gears. I'd assume this shouldn't happen as the piston would then be under pressure by the spring and gears.

I have re-greased all parts.

Any help much appreciated. don't fancy braking a third.

Masada

the gears have to be timed, did ya do that?

kdouglas

timing (i.e. setting the sector to 1 o'clock) is commonly thrown about as an important thing to do, it's completely unnecessary, once the gears are not in contact with the piston when you close the gearbox and the tappet plate is in the right position your fine, visualise a gearbox in your mind, and go through a couple of revolutions, no matter where you set the gears (and the pickup for the tappet plate), they'll sort themselves out after one turn

DevilsBreath: if the piston is not going fully forward by the time your gears go around again, what is causing this? either the piston is moving too slowly or your gears are moving too fast, at really high ROF (i.e. 30rps+), your gears get to a point where they are turning faster than the length of time it takes for the piston to move from the back of the gearbox to the front

is the gun firing properly at all? if the piston isn't travelling all the way forward, then you should be getting a pretty pathetic fps
check the rails that the piston sits on, is anything causing it to jam or stick while moving?

Cuddlesworth

kdouglas wrote: »

DevilsBreath: if the piston is not going fully forward by the time your gears go around again, what is causing this? either the piston is moving too slowly or your gears are moving too fast, at really high ROF (i.e. 30rps+), your gears get to a point where they are turning faster than the length of time it takes for the piston to move from the back of the gearbox to the front

is the gun firing properly at all? if the piston isn't travelling all the way forward, then you should be getting a pretty pathetic fps
check the rails that the piston sits on, is anything causing it to jam or stick while moving?

Piston is greased up with silicon grease, everything is in place correctly. The gun fires correctly on single, full auto burst sometimes leaves the piston in a random position.

It might be the ROF, that motor was stupid fast with a 8.4, so we put a 9.6 in for fun. Another reason to buy a multi shot Chrono 'DB'.

DevilsBreath

Ye thats the thing the gun fires perfectly.

It's only when fireing on quto that this happens it all depends on how long you hold the triger down for.

It's as if im firing 2.5 time's rather then 2 or 3. it seems to stop in the middle of the rotation but not all the time.

This is why im wondering is there a timing issue.

Thanks for all the input as im stumped.

DevilsBreath

krazy_8s wrote: »

Another reason to buy a multi shot Chrono 'DB'.

I'll get around to it as soon as my credit card stops hissing at me.

kdouglas

i have a chrono on the way which does rounds per second, but in the meantime, i use a piece of software called audacity, it's a sound editing program that shows a wave graph of the audio when you record it, fire for a few seconds or so, then zoom in and count the number of peaks per second

Cuddlesworth

kdouglas wrote: »

i have a chrono on the way which does rounds per second, but in the meantime, i use a piece of software called audacity, it's a sound editing program that shows a wave graph of the audio when you record it, fire for a few seconds or so, then zoom in and count the number of peaks per second

Sweet, now I can use my A&K if its under a joule.