Piston teeth removal...

[Benjii]

Hey people,

In my ICS M4 full custom, high 'ish' speed setup, ie, high speed motor, 13:1 gears. I have an element duracon piston which has the first tooth already removed. The gun has been reshimmed and the AOE corrected with sorbo pads, and the second/third teeth are being worn down.

I assume this isn't a problem, but obviously scrapings of the piston getting knocked around everywhere isn't a good thing, so should I just remove them?

What's the most teeth you can remove?

Cheers for the upcoming help! (hopefully)

Ben!

[WW2Stu]

Re: Piston teeth removal...

Do you have your old piston and piston head? If you do it may be worth measuring them up to see what the difference is in height between your new and old setup. I have never had to remove a tooth on any of my pistons just for the the simple fact of buying a couple of extra pistons from different brands and seeing which one sizes up best.

Hope this helps

Stu

[Benjii]

No, it's an element piston and SHS piston head. I don't really have enough money to buy a few!


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[Benjii]

I need the help please!


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[WW2Stu]

Re: Piston teeth removal...

Well what I have posted is help. I know its a bit late now but just to reiterate:

Buying "lesser" branded stuff made to lower tollerences, is never a good idea. SHS and element both being part of the cheap and cheerful catergory.
You dont have a spare £25 quid to pick a madbull and classic army piston? You are not wasting them, they are investments as if you dont use them, you still have them!
And the problem again is the length of the piston / piston head cutting teeth off is a dirty fix which you are not actually fixing anything. Your gearbox is still out of sync and other teeth will still get stamped destroying your already slightly damaged piston. (Isn't that a waste of money?)

Stu

[seansamurai1]

Re: Piston teeth removal...

Right, SHS stuff is quite good, Ive had no issue with the gearsets, far out lasted G&P stuff and certainly Systema gears as well, and the aint cheap and cheerful.

The front teeth of the piston take pretty much the worst punishment. Best bet is to check the shimming AoE again to double check its correct, take the spring and ARL out and spin the gears slowly to check the engagement all the way along the piston.
Make sure the piston has the same amount of teeth as the sector gear.

Your other option should all else fail is to buy a new piston with the 7 metal teeth on the front. That will increase piston life but also give you the option to grind down the front teeth to short stroke (which lowers FPS).

[Darkmikey22]

Re: Piston teeth removal...

i agree that shs stuff isnt that bad as sum make out. but if your having trouble with gears imo i would only by a nylon teeth piston. coz if there is a problem you will only strip the piston teeth and not damage the gears.
as above really, make sure its shimmed correct and the gears are spinning correctly.
i know this may be nothing to do with it but will ask anyway, but are you using the original bushes or have you changed them too?. i only ask as old ones could be worn (depending on age and usage) and causing a bit of play in the gears, or new ones may be sitting slightly off or not pushed in enough.

[tsv2tuff]

Re: Piston teeth removal...

nothing wrong with SHS stuff.... with sorbo pads in you want to remove the first 2 teeth and half of the 3rd one if you have to. obviosly dont remove more than you have to. also as the sorbo pads reduce your cylinder capacity your fps should have dropped since installing them? in which case you can put a stronger spring in forcing the piston back to its origanal place faster and preventing premature engagement.

[Bachelarius]

Re: Piston teeth removal...

Could you post up a pic of the wear pattern?

My immediate guess would be pre-engagement (PE), which definitely needs to be dealt with. As far as removing teeth, you only need to remove precisely that which is getting in the way, so the first tooth of the gear can reach the first (rear-most) tooth of the piston when the piston is in the fully-forward position. Leave as much of the 3rd tooth as possible to allow the gear's first tooth to pass over it during pickup. You shouldn't need to

To stop PE, you need to increase piston return speed. There are 4 ways, the order I would do them in is:
1 - Make sure that there is NOTHING interfering with the piston return (so very thin film of lubricant on the O-ring, cylinder, piston rails and gearbox tracks and smooth, polished piston tracks)
2 - Lighten the piston (swiss cheesing)
3 - Drop a heavier spring in (if your FPS is way )
4 - Short-stroke.

Any of the above will be a good solution. It's ordered in the order that I would personally choose do it, but if your FPS is significantly below limits, then getting a heavier spring would be higher up the list and have more return, but don't discredit Short Stroking - it's got rid of mild PE completely for me in the past.

[North West Outpost]

Re: Piston teeth removal...

Well what I have posted is help. I know its a bit late now but just to reiterate:

Buying "lesser" branded stuff made to lower tollerences, is never a good idea. SHS and element both being part of the cheap and cheerful catergory.
You dont have a spare £25 quid to pick a madbull and classic army piston? You are not wasting them, they are investments as if you dont use them, you still have them!
And the problem again is the length of the piston / piston head cutting teeth off is a dirty fix which you are not actually fixing anything. Your gearbox is still out of sync and other teeth will still get stamped destroying your already slightly damaged piston. (Isn't that a waste of money?)

Stu

Sorry to tell you that you are just showing a huge lack of experience. Given a choice I would only EVER buy SHS pistons.

When you say AOE corrected have you set the AOE or just slapped some sorbo in there and hoped it has moved the piston back to the right position?

Photo!