Gearbox issue w/M120

[etd]

My JG mechbox (fully upgraded) won't fire when I add a M120 spring to the mix to replace a 300 fps spring I've been using for the past year. The piston has some standard wear on it but nothing to bad yet.

I'm running a 8.4 1100 and a system Magnum motor. Gun fires just fine and crazy quick with the 300 fps spring. I've tried re-shimming the gears and inspecting them for any faults.... I'm stumped.

Other parts to note: Bearing metal spring guide, sorbo pad.

[cerealmaniac]

try using a different battery, or adjust your motor height. i've had similar problems with a V3 gearbox.

[etd]

Adjusting my motor height is a major problem as I have a magnum motor... basically I have to jam it in the V3 motor mount or I can't do squat......

I know its at the proper height because its not stripping, no rotations are being placed and I've already tweaked the height with the 300 fps spring prior to upgrading the spring. As for the battery I'll see if I can borrow one. If anyone else has a different theory I'm all ears.

[Amos]

Motors can be "not stripping" and still be adjusted very poorly, if you've got too much forward force on the motor it can cause a huge strain.

My thoughts on this is that your battery is unable to provide the power that the motor requires to pull the heavier spring.

I would have your motor looked at by some one that knows what they're doing, Systema magnum motors are notorious for being poorly shimmed, balanced and sucking down 5X the power that they should.

[Styrak]

You need a bigger battery.

[venture]

The spring you have may have a longer "length before set" (i.e. squeeze the spring fully and measure the tube that gets formed) and be stopping the piston from fully coming back. This can happen when a long spring is used with a bearing spring guide and a bearing at the piston head as well. If you have 2 or more bearing then beware of this problem.

It is simple to fix though, just take a turn or 2 off of your spring. Or remove a bearing if you don't mind losing free spring rotation.

Anyway just another possibility, although rare, it is worthwhile to make sure it IS NOT it. It may not be this but if it is then it is a critical problem that can only result in jamming or breakage.

[etd]

Omg thank you so much venture. I have a bearing piston head/spring guide and when I managed to manually fully compress the spring it WAS much longer than my travel length. Also thank you to Styrak as his idea did actually pull the piston back a little more.

[venture]

Originally Posted by etd

Omg thank you so much venture. I have a bearing piston head/spring guide and when I managed to manually fully compress the spring it WAS much longer than my travel length. Also thank you to Styrak as his idea did actually pull the piston back a little more.

No Problem, No Charge. Hope I helped save your piston or sector gear.