High rof destroyed my gears - what extra should i look at doing?

[badas]

Hi all,

This is regarding an M4 I have. It is a Tokyo Marui gearbox and works great on a 7.4V (all day long with a few thousand rounds going through it) but i hooked a 11.1V lipo to it and it lasted about 3 mags until teeth were stripped from the middle gear and the one that turns the piston.

The piston though is un damaged and so was the first gear that the motor turns.

So i wanted to know if i want to be using 11.1V in this M4 happily, what gear set should i be looking at getting to tolerate the high rof?

What other parts should I consider getting also? The motor is of an unknown make but is very fast. The reason for me wanting an 11v lipo is because it fits nicely into a Peq box, unless someone can name be a small blocked 7.4V 1200/1400/ lipo?

Thanks

[Bachelarius]

Re: High rof destroyed my gears - what extra should i look at doing?

Well, shimming sounds like a possible issue in this case, let me dig up a fantastic little video which explains it perfectly.

http://www.youtube.com/watch?v=1F0zpkmNux4

Goes into a great level of detail as to what causes various gear strips etc.

Also, bear in mind that marui gearboxes are not the most fantastic in the world. They are well tuned for stock performance, but don't really like high stress stuff. Get some sorbo to protect the case, try some high torque gears to slow it down a little bit (shs make a few good sets) and shim them all to hell. Also you will need solid bushings in there as well, avoid oil channel ones as they destroy gear shafts.

[badas]

Re: High rof destroyed my gears - what extra should i look at doing?

Thanks, trust me i know how to shim :P

Watching the video and has some interesting tips too, Personally think TM gearbox's are crap... it came with loose plastic bearings :S

I already have sollid metal bearings (bushings) in ittoo but will look into the SHS gears.

Thanks

[badas]

Re: High rof destroyed my gears - what extra should i look at doing?

Supergluing bushings in is new though :S

[Fuzzy]

Re: High rof destroyed my gears - what extra should i look at doing?

Helical gears?

Midas will be here at one point, he's an expert with high speed set ups.

[balaclava ben]

Re: High rof destroyed my gears - what extra should i look at doing?

does the piston used have a metal or plastic toothed rack?

[richardy]

Re: High rof destroyed my gears - what extra should i look at doing?

Thanks, trust me i know how to shim :P

Watching the video and has some interesting tips too, Personally think TM gearbox's are crap... it came with loose plastic bearings :S

I already have sollid metal bearings (bushings) in ittoo but will look into the SHS gears.

Thanks

How can you know how to shim properly if you don't know the contents of the most common gearbox. It's Airsoft bread and butter. Also that an 11.1v would do that. New bearings new gears and check the pistons aoe. That should be enough to get it going again.

[North West Outpost]

Re: High rof destroyed my gears - what extra should i look at doing?

I agree with Richard. Shim and AOE will be enough for an 11.1 with standard motor.

[badas]

Re: High rof destroyed my gears - what extra should i look at doing?

I know how to build it all but I don't know the technical name of each piece.

So your saying standard TM gears should have operated fine using an 11v battery? (providing shimming and AOE is set right?)

Thanks

[balaclava ben]

Re: High rof destroyed my gears - what extra should i look at doing?

i've been running my tm p90 with a panther mosfet, 11.1 lipo, deans, low resistance wiring, short stroked piston, element max speed motor, and guarder strengthened tappet and its had zero problem's so far!

[North West Outpost]

Re: High rof destroyed my gears - what extra should i look at doing?

I know how to build it all but I don't know the technical name of each piece.

So your saying standard TM gears should have operated fine using an 11v battery? (providing shimming and AOE is set right?)

Thanks

Yes.

[North West Outpost]

Re: High rof destroyed my gears - what extra should i look at doing?

i've been running my tm p90 with a panther mosfet, 11.1 lipo, deans, low resistance wiring, short stroked piston, element max speed motor, and guarder strengthened tappet and its had zero problem's so far!

SHHHH....That's done it now..

[badas]

Re: High rof destroyed my gears - what extra should i look at doing?

Ok thanks, going to go take a look at re shimming my m4 then :P

[sj_asc]

Re: High rof destroyed my gears - what extra should i look at doing?

Almost all TM sets fail the sector and corresponding spur teeth, the sector gear is very poor pressed zinc alloy which is massively inferior to steel, not to mention that the TM teeth are very low profile. They will fail in no time at speed under higher load regardless of how well they are shimmed.

A decent steel gear set and bushings, good shim job, AoE correction and a spring rate matched to the intended fire rate will ensure that the build will last.