Pistons

[Big Pepa]

Originally Posted by Multikam

I think if your rof is too high there isn't a piston out there that can handle such demanding use. Maybe you should lower the rof (lower the battery voltage or change to torque gears).

I whole heatedly agree with you, BUT... I just can't do it

[ILLusion]

I actually disagree with that statement. There are ways to attain the ROF goals you're currently trying to reach AND surpass it. You just have to be open to this ideas and willing to actually put them in to action.

[Dragate]

I'm not speaking from personal experience, but what I have been reading.
It's probabaly your shimming. What is your rof around?
If you want perfectly shimmed gears, get them modify modular hi speeds for your high rof, and you won't have to worry about shimming. Also, try for 8mm bearings, if you don't already have those.

[ILLusion]

Poor shimming wouldn't strip pistons.

[Big Pepa]

Originally Posted by Dragate

I'm not speaking from personal experience, but what I have been reading.
It's probabaly your shimming. What is your rof around?
If you want perfectly shimmed gears, get them modify modular hi speeds for your high rof, and you won't have to worry about shimming. Also, try for 8mm bearings, if you don't already have those.

Not the shimming

Also, using bearings in a High speed set up is a recipe for disaster. If your bearing pops your gears, piston, and everything else in the gearbox has a pretty good chance of getting destroyed. I've never seen 8mm bushings.

[Big Pepa]

Illusion

Would short stroking the gears reduce the FPS? I'm working with limited FPS, as I mentioned before, and that is my primary concern with short stroking?

I realize that the piston will go through the entire compression cycle, especially on an MP5, since the port on the cylinder is 1/4 the way down. That said, the spring wont fully compress and, the way I see it, that means that it won't decompress with the same energy. Is this logic correct?

[Amos]

If you short stroke it past the hole in your cylinder then yea it will degrade your FPS, but it you keep it to before the hole you shouldn't see any problems.

[ILLusion]

Originally Posted by Big Pepa

Illusion

Would short stroking the gears reduce the FPS? I'm working with limited FPS, as I mentioned before, and that is my primary concern with short stroking?

I realize that the piston will go through the entire compression cycle, especially on an MP5, since the port on the cylinder is 1/4 the way down. That said, the spring wont fully compress and, the way I see it, that means that it won't decompress with the same energy. Is this logic correct?

Your logic does have merit, but it's not a huge concern. I've only done a short stroke mod once, so I can't give solid results to cover a general scenario, but in that one setup I built, I'd only lost about 5fps in a 330fps setup. That type of velocity loss is negligible.

[Big Pepa]

Played today all day without chewing a piston. I got the aluminum one in reserve. Next time I chew it up I'll shove it in and short stroke the gears. Thanks for all the advice and tips on this topic

[ujiro]

So, trying to figure this out. Is shaving the 2nd tooth a precautionary measure only useful on high RoF set-ups? Or useful for all AEGs. My gun isn't made to be a high rate of fire rifle, but it fires quite quick due to the battery I use. Thanks in advance.

[Big Pepa]

Originally Posted by ujiro

So, trying to figure this out. Is shaving the 2nd tooth a precautionary measure only useful on high RoF set-ups? Or useful for all AEGs. My gun isn't made to be a high rate of fire rifle, but it fires quite quick due to the battery I use. Thanks in advance.

It's only really necessary for high ROF setups since less travel time of the piston = less chance the gears will catch it before it hits battery. I don't think shaving the 2nd piston would hurt any AEG but there is really no point in doing it unless you got a high RoF.

On a stock gun shaving the second tooth would be something like changing underwear 5 times a day... you could if you wanted too but, unless you got serious bowel problems, there is really no point.

It would however marginally increase your RoF. There are way better ways to go about that though.

[ujiro]

Fair enough, thanks for the advice pepa.

[Dragate]

Originally Posted by ujiro

So, trying to figure this out. Is shaving the 2nd tooth a precautionary measure only useful on high RoF set-ups? Or useful for all AEGs. My gun isn't made to be a high rate of fire rifle, but it fires quite quick due to the battery I use. Thanks in advance.

This isn't due to personal experience, but from waht I head it's a good mod to do to keep your piston healthy and have a long life.
Usually when adjusting the angle of egagmeent with the piston, there will be pre-engagement issues that come with with the gears, requiring shaving down some or even all of the tooth and more...
Even without adjustment of AOE, ur piston and gear at one point will reach taht proper angle, just takes some extra work before it gets there straining the first tooth, and means you would still have the same preengagement issues with a proper AOE or not.

Originally Posted by Big Pepa

On a stock gun shaving the second tooth would be something like changing underwear 5 times a day... you could if you wanted too but, unless you got serious bowel problems, there is really no point.

lol a bit of an understaement to the importance of it.

[m102404]

KingCobra was over the other day and showed us a sample of his short stroked piston. In his current high-ROF setup, he's using a M160 to generate 380-390fps at the muzzle. There's a lot of teeth missing on his pistons....

Carefully assessing if you need to shave/remove/do-nothing to the second tooth is never a bad thing whenever you change gears/piston/piston-head/cylinder-head parts.

High ROF is neat to fool around with...but most of the decent games around here don't need it. 25+ RPS at just under 400fps would hurt like crazy...I'd rather get a 203 at close range than to take a long burst from one of those. KingCobra does it for fun...not for gaming. It also seems like he's also over at Airsoftparts.ca every other day getting replacement parts...so factor that in

I've not been overly careful to perfectly mate the angle of engagement between the tooth surfaces...but it does have merit, especially if it's quite a bit off. I've only adjusted it occasionally.

Plastic sheet (like acetate sheet) make good thin shims, metal sheet make good thicker stock, and the worse one I encountered needed a washer (the setup was just slightly less than 1mm too short).

[ILLusion]

Originally Posted by Big Pepa

On a stock gun shaving the second tooth would be something like changing underwear 5 times a day... you could if you wanted too but, unless you got serious bowel problems, there is really no point.

The Tokyo Marui P90 actually comes straight from the factory with the 2nd tooth already removed.

It's also quite a high ROF gun when stock, even with a mini 8.4v 600mAh Nicad pack, so it's probably put in for extra durability.