complete striping of a piston...

[ErikMendel]

yeah. im not convinced that metal pistons worth 20 bucks it worth risking a helical gear set worth 60 i like the idea that you have a manufactured weak point that is cheap and easily replaceable, and i really dont see why swiss cheesing a piston would change the structural integrity in anyway, the spring resting on the back of the head, having no pressure what so ever on the side walls. their is no situation in any aeg which causes sidways forces to the piston. the whole reason that i started this project was because when i run the kong power 3 cell 1300 mah lipo i have. their were significant feeding issues , hence (the sector clip). im starting to see that my errors in this were using a piston with only one steel tooth. im thinking in dropping the 130 spring for a m120. im not interested in going to much lower due to the issues of lack of reliability. lurkingknight i see one problem with your statment about over paying for systema. i found 3 sites with systema enrgy pistons for under 13 bucks. every other piston in canada modify, ics run about 24-40 bucks systema is cheaper ...... altho the full metal tooth piston on http://www.airsoftstore.ca is kinda cheap for 10.50 but before i go out buying a fully metal piston does any one have experience with premature wear on your gears due to running full metal teeth? deathfox- both pistons were matched in tooth removal to the sector gear 1 off each. and the systema cylinder head has an excellent shock pad on it, thus it is doubt full that the problems arised from bouncing off the head. just to clarify i believe the issues to be removing the 1 metal ketch tooth from the systema piston. it seems more likely a cause then the piston being caught with pre engagement due to the fact that every single tooth is worn flat not a bunch starting halfway up the piston and moving back.... i appreciate all of your imput, i like geting the bigwigs of air soft together and seeing their different opinions...... 2 last questions deathfox get some sector clips at your store and steel tooth pistons what are your thoughts??

[MaciekA]

Originally Posted by ErikMendel

does any one have experience with premature wear on your gears due to running full metal teeth?

No. That is not an issue with the SHS full metal racks.

The rest of your post, and most of what we've discussed up to this point, is pretty much irrelevant. Just go buy a couple of the SHS pistons and move on. They are being used in much much more abusive builds than your relatively lightweight M130 build. And seriously, stop buying Systema parts.

In the meantime, you have a far more serious problem. I recommend going to this site to fix it:

http://www.bobbrooke.com/WritersCorn...swhentouse.htm

[lurkingknight]

metal wear occurs to the weakest link in the chain... if your gears are made of butter, then they will wear (or fail long before they wear out) If you have nice hardened steel gears, it won't be an issue. If your AoE is properly adjusted, it should be even less of an issue.

Originally Posted by Deathfox

My statement was bias, i personally dont believe in swiss cheesing pistons. Im weary on it because it does change structural integrity of the piston.
The gun in question never had a problem with it for 20k rounds, then he short stroked it and then swiss cheesed it and failed almost right away. So im still standing by my statement because the gun had no wear before those modifications... and those modifications would have made it less of a chance for for the "crashing problem" as you stated. So i still say its the piston bouncing off the piston head And causing a engagement problem. I would suggest a sorbo pad because this would keep it from "bouncing" off the cylinder head. This is a common problem in high rof setups, and you cant get the best of both worlds (FPS & RPS)

. Ive never found the need to use swiss cheesed pistons because i can manage to get 45rps on a single sector without swiss cheesing. And i get great piston life (with AoE)

But i will have to agree with ya on SHS metal rack pistons. They are great pistons (and cheap)

Just as a topic of technical discussion, when was the last time you saw or read of a piston losing structural integrity in the middle of the body? Every piston failure I read about is about pre engagement or bad AoE shredding the teeth off the rack, or the piston material is too heavy or brittle (metal pistons) that can't take the shock load and shear completely off at the pickup tooth and the end of the piston. You never see a failure of the piston due to a good swiss cheesing treatment. And OP stripped the teeth on the rack, there was no structural failure of the body. I don't see how the rack's integrity can be weakened by swiss cheesing the body unless he tore the rack completely out of the piston.

As for the piston bouncing, I'm not convinced that's what's happening. The motor and gearset is more than capable of creating an rpm greater than the return speed of a piston. It's far more likely he's getting overspin on the gearset, causing his pre-engagement.

[MaciekA]

Originally Posted by lurkingknight

metal wear occurs to the weakest link in the chain... if your gears are made of butter, then they will wear (or fail long before they wear out) If you have nice hardened steel gears, it won't be an issue. If your AoE is properly adjusted, it should be even less of an issue.

Just as a topic of technical discussion, when was the last time you saw or read of a piston losing structural integrity in the middle of the body? Every piston failure I read about is about pre engagement or bad AoE shredding the teeth off the rack, or the piston material is too heavy or brittle (metal pistons) that can't take the shock load and shear completely off at the pickup tooth and the end of the piston. You never see a failure of the piston due to a good swiss cheesing treatment. And OP stripped the teeth on the rack, there was no structural failure of the body. I don't see how the rack's integrity can be weakened by swiss cheesing the body unless he tore the rack completely out of the piston.

As for the piston bouncing, I'm not convinced that's what's happening. The motor and gearset is more than capable of creating an rpm greater than the return speed of a piston. It's far more likely he's getting overspin on the gearset, causing his pre-engagement.

+1

Completely agree on each point.

To the OP:

1) Keep the M130 spring to avoid pre-engagement and ensure rapid return.
2) Buy a strong steel racked piston (SHS).
3) Buy strong steel heat-treated gears (SHS are fine, but Siegetek are best)
4) Lighten your piston by removing the metal bearings and possibly swiss-cheesing (rapid return). Ignore strange theories of bouncing and structural integrity. These are not real issues.

And you'll be fine assuming you've done everything correctly. As far as Systema parts go, I haven't used their gears or pistons but have always stayed away due to price and above all due to the reputation of those parts being made of softer metals.