Mystery: Constand Piston Damage

[lurkingknight]

gear timing on assembly? think about it.. if you pull your trigger and release it before a cycle finishes... where does the sector gear end up? Somewhere mid cycle. Could be anywhere from not engaged on the piston to fully engaged mid pull on the piston to full cock before it releases.

What happens when you pull the trigger again? it finishes cycling, doesn't matter where the gears sit, it will go. The tappet peg is fixed, and the sector segment are fixed, all other teeth are fixed ratio, it's like asking where the bottom of a circle is. It's not like you have a cam with multiple pistons being pulled at different intervals.

As long as you didn't mesh your sector halfway through a piston cycle... which is highly unlikely you could reassemble the gearbox with out all the parts blowing up trying to get the 2 halves together because it's under tension.

[porkinglot]

I have to agree with some of the other guys here, I think its the 11.1lipo.
I had one on my ICS M4 and it seemed to cycle dangerous fast, as if I put a 12v battery in it lol. So I got a 7.4 15c and it acts more like a 9.6 NiMH, but with a snappier trigger, and no arching on the contacts.
I don't think the ICS split gearbox can handle a 11.1 without major upgrades. And to me at least it just didn't sound right, like the gun actually sounded rough and 'grindy'.
My 0.02$ is, get a stock TM Piston or any of the ones listed, a 7.4 15C lipo and check it over 3x before you put it back together.
Best of luck!

[Kos-Mos]

Originally Posted by porkinglot

as if I put a 12v battery in it lol.

Yeah, might be because a fully charged 3cells LiPo peak at 13.95v...

While a car battery peaks at 13.3-13.5v...

[Moonschlagen]

I highly doubt the 11.1v lipo is the cause of the piston stripping if the gearbox has been properly shimmed and AOE'd. I'm running an 11.1v 3300MaH 50c in my ICS gun and it runs flawlessly. The gearbox is stock with only the cylinder head and nozzle changed out for Modify parts to increase compression.

[Kos-Mos]

Originally Posted by Moonschlagen

I highly doubt the 11.1v lipo is the cause of the piston stripping if the gearbox has been properly shimmed and AOE'd. I'm running an 11.1v 3300MaH 50c in my ICS gun and it runs flawlessly. The gearbox is stock with only the cylinder head and nozzle changed out for Modify parts to increase compression.

How many ICS guns did you have?

Theses are not hand-made. There are variations from each batch.

It can be as simple as a crooked guide rail for the piston that slows it down a 10th of a second, just enough to let the gears catch 1 extra teeth.

[Maethori]

The black Modify piston with gold trim sounds like the Quantum. It has titanium coated steel teeth. This should be very difficult to break.

Just looking at the few details you mentioned I would say you need neither the 11.1v LiPo or the high torque motor. Like others have said, I would first recommend switching to a lower power battery. I only use 7.4v LiPos and they work perfectly for every gun I have.

[Heimdall]

This is all great feedback. Thanks. I have a 9.6v NiCd battery that I haven't used so I'll try that along with a 7.4v LiPo.

I agree with Kos-Mos; you're lucky that it works with your gun but with mass produced tech it's a rare chance that they all work congruently with one another (I sell cameras and the frequency of subtle variations is absurd).

The SHS 15T Piston has been ordered and should arrive tomorrow. I'll get started asap.

[Heimdall]

Gear timing is correct, new piston installed, using 9.6v NiCad battery, tested with both 330 fps and 400 fps uppers.

There's no visible stripping but there's no velocity in the bbs.

Air seal is perfect, hop-up is clean and clear, mags feed perfectly (tested those on my friends gun as well), tested with other mags. Bbs keep rolling out... I'm confused.

[Heimdall]

Could dirt build-up cause any of these issues?

[Heimdall]

In any case, everything has been cleaned and lubed. However, my safety pin turned out to be shattered. Either a gun doc I had tune it a while back or the original owner over tightened it.

I'll try super glue or creating and adhering a new machines thread.

[Kos-Mos]

Just order a replacement... that is one of the parts that is standard in the ICS M4.

And that much grime in your mechbox can probably have damaged your cylinder and piston head, maybe hop-up sleeve and nozzle seals too...

Remove the compression parts and test them outside the gun. With the nozzle on, you should barely be able to push down the piston in. Without the nozzle, it should not move past the last quarter.

[Heimdall]

Am I incorrect in calling that piece the 'safety pin'? I've looked on airsoftparts, airsoftdepot, TorontoAirsoft, airsoft GI, redwolf, Toronto Airsoft, and ehobbyasia. Google doesn't provide any term matches. One video I've seen that shows step-by-step disassembly refers to it as the safety pin. I'd rather be sure.

[Maethori]

Well...safety lever, but close enough.

Also, it sounds like you might have a compression problem somewhere. Occasionally perfect compression is actually bad, from what I've seen. It might be too much compression for the system to push fast enough, or something like that.
I've worked on a stock KWA m4 that had super low fps with perfect compression (using a Modify piston) but had much higher fps and amazing consistency, range, and accuracy with the stock piston and definitely-not-perfect compression.

[Heimdall]

The safety lever arrived just a few days ago so everything is clean and reassembled. The gun is still having trouble feeding. I completely turned on the hop-up so the bbs finally had some velocity there's still some jamming and compression issues. I bought a new sorbo pad and shs aluminum nozzle.

I don't own a chronograph but have heard of the pop can method; how far do I have to be to judge its velocity? I keep hearing that if it only breaks the first wall from point blank it should be good for indoor. Can I get a confirmation of this?

[Moonschlagen]

Hey Heimdall, perhaps buy a sector chip/delayer for the sector gear to fix the feeding issue you have. They are real cheap and worth a shot. It seems your problem is a compression leak between the nozzle and hopup chamber. Try shimming the hopup with an o-ring to produce a tighter fit with the nozzle.