Semi-Automatic is now 'random amount of shots' mode...

[BikerEddd]

Ok iv just done a ROF upgrade on my CA G36C and have found now that in semi-automatic sometimes it fires one shot sometimes two and sometimes even more. I have a relatively good idea of how a v3 gearbox works and do all my own work on it and i assume that the reason for this is that with the high ROF the cut off lever can't lift the trolley up before a second shot is already happening... after a lot of goggling I have heard a lot about adding JB weld to the cut off lever and/or upgrading it? I was wondering if any one else had had this happen and had any advise?

Thanks in advance

[Phatvortex]

Re: Semi-Automatic is now 'random amount of shots' mode...

I'd check that the spring for the cutoff lever is still nestled in the selector plate. After that, look at getting a new cutoff. You shouldnt need to mod it unless you're running a mental ROF.

[sj_asc]

Re: Semi-Automatic is now 'random amount of shots' mode...

It's a problem that is more common with very high rates of fire.
If it's not a fault with the cut-off assembly it's self it will be because there is too much residual momentum from the motor after the power has been cut, sometimes enough to half cycle or even fully cycle another shot after the trolley has returned.

It is a problem that is more common in setups with non-neodymium magnet equipped motor cans and or stock or higher than stock ratio gear sets paired with lighter spring rates.
You could do some fine tuning with the cut off cam/timing, but youd likely run into issues when cycling lower rates. Much like different cam profiles in engines.
The tried and true method is the active braking MOSFET, it kills the motors CEMF by shorting the two terminals when the power is cut, stopping the motor very quickly.

[BikerEddd]

Re: Semi-Automatic is now 'random amount of shots' mode...

My ROF is around 20rps, (1200rpm). I did consider it may be the residual momentum that you mention. At the moment the FPS is around 290/300 with a .2gbb so i'm upgrading that as close to 350 as I can get it so that might help. If not I may have a look at moding or changing the cutoff lever. The gun is not that old so i doubt it is worn out. Are there any aftermarket cutoff levers that are designed to counter this problem? I might look into getting a AB Mosfet. I am already running a standard Mosfet. Ideally il look into the simple solutions and mods first though I'm better with my cogs than with my wires thanks for the help guys Will update when I get this new spring in and check everything is as it should be.

One interesting thing I have noticed. It works in semi perfect every time when it isn't fireing bb's (dry fireing) but as soon as I put BB's though it the problems start. Could this be anything to do with it? Cheers

[sj_asc]

Re: Semi-Automatic is now 'random amount of shots' mode...

I'm sure the spring will cure the problem, however if the problem doesn't disappear after you've installed a 350fps rate spring for 20rps then it is certainly to do with cut off timing.

[Stealthkiller]

Re: Semi-Automatic is now 'random amount of shots' mode...

Sector clip / chip could cure it. . What voltage batterys are you running ? Does changing mag types cure the fault . ? Mid , highcap . There are quite a few variables to what is causing your overspin problem . Go with the basics first and then start working towards the more expensive / technical solutions .

[BikerEddd]

Re: Semi-Automatic is now 'random amount of shots' mode...

I'm already running a sector chip and I have no problem with feeding I don't have any other mags to try so yer I guess we'll just see when my new spring comes cheers