m60 keeps shredding pistons

[SlowEddy]

my ares m60 keeps shredding pistons.
the stock piston lasted the longest with about 400-500rounds fired. I have gone though another 3 spare pistons i had lying around:
2X TM (1 with 1 tooth removed and the other with 2 teeth removed)
1X madbull(full teeth & aluminum piston head)
all 3 pistons lasted about 100-200 rounds before completely failing. (pics below)

I'm using a large 8.4v battery, stock internals shooting .28's at about 270FPS with a ROF of about 18bb/s

any ideas of whats causing this? , my guess is a bad AOE?
but could it also be gear shimming?


I am also trying to decide on which pistons i should try next, any remonstrations? I was thinking about these 2 but I'm afraid of shredding them seeing how i have already gone though 4 pistons......

Modify High Speed Ultra Piston - New Version
http://www.airsoftparts.ca/store2/in...oducts_id=1369



MA Titanium Piston - Full Teeth
http://www.airsoftparts.ca/store2/in...oducts_id=1376

pics of my poor pistons

Stock piston


TM piston( with 2 teeth removed)


Mad bull piston (with aluminum piston head)

[theguy]

Yikes, i remember seeing this at FR a while back.

Try a piston with metal teeth?

[The Acer]

i would think it would be either a bad shim job, or bad gears, any pictures of the gearbox, that might help

[The Saint]

The type of damage is not consistent with bad shimming (width of wear is too consistent). Using metal teeth piston to fix a mysterious teeth stripping is asking to strip gears.

I think the OP's suggestion of AOE is most likely. It looks like the piston is too far forward for the first sector tooth to mesh with vertical surface of the first piston tooth. It looks like it's meshing with the bottom of the first piston tooth and crushing the area upwards.

[m102404]

your piston/gear teeth engagement is off at speed.

You're shooting a pretty mild spring (guessing it's a m100) to get 270 w/0.28's. A stiffer spring will return the piston forward faster...in order to be picked up by the sector gear properly.

With a metal rack of teeth...either the rack will break (and probably break something else as well) or the gear teeth will break as it's setup right now.

Sounds silly...but you can "test" the setup with a 7.2v battery and/or a weaker motor first to see that it's running right...then ramp up to a bigger battery/motor.

Tys

[Ronan]

AOE = Area Of Effect. What about in airsoft?

[ujiro]

Angle of engagement. Of the sector teeth onto piston

[Ronan]

Originally Posted by ujiro

Angle of engagement. Of the sector teeth onto piston

Ah didn't know it was called that, thanks m8.