`Half engage on semi problem

[kilo_64]

I just rebuilt my gearbox and installed a set of systema helical gears.

 

After spending a good amount of time shimming these things to perfection; I decided to put the box back together.

 

The piston in question is a stock G&P white piston and the cylinder in question is a stock type 1 cylinder.

 

I also have a system anti reversal installed as well.

 

The gearbox cycles perfectly and rof is scary but what the problem that I keep getting is that on semi; my piston would fire and not reset.

 

What I mean is that from a full rest position (Piston disengaged, taplet plate disengaged) and onto semi fire; the piston would fire and not reset to rest position.

 

Instead, it would rest semi engaged (Piston halfway cocked back with spring engaged)

 

I can't seem to figure out what is going on except that I might be using a wrong piston for the gears? Or that the gears are spinning so fast that its catching the piston a second time before it could fully rest?

 

For those who might bring up my cut off lever, it is perfectly fine and functions as it should (cutting off)

 

Any input from prior experience would be great.

 

Heres my set up just incase:

 

7mm gearbox

BB Spring guide

m120 Spring

G&P Piston/Guarder Piston head

Stock Cylinder type 1 and head

Systema Nozzle

Systema Taplet Plate

Systema Helical Gears

Systema Anti Reversal

 

Systema Magnum Motor

 

11.1v Lipo Battery

[Docv400]

...the gears are spinning so fast that its catching the piston a second time before it could fully rest...

I think you'll find that's normal when you have a much higher than 'average' ROF.

It's just the extra inertia causing the motor and gear-train to over-run slightly, just like a car takes a bit longer to stop from higher speed.

 

As long as it's not firing twice in semi, is it a problem?

The only way to stop it happening (without changing your gearbox set-up) is to fit a MOSFET with 'passive braking'.

 

 

[kilo_64]

Thanks for the response!

 

To answer your query as to if its a problem;

 

Yes, yes its a problem because I can't decompress my spring to relief tension

[magic_golem]

I agree that it sounds like an overspin problem your having, have you tried a lower voltage battery to see if occurs at lower speeds? helps to narrow things down when going for high rof setups.

[midas]

I would suggest an AB mosfet, if you like the rof. Or different battery if you prefer not to instal a mosfet.

 

One of my setups in an old AK even with a mosfet used to overspin at 35rps....lol..

 

But was fine at 33.