overspin/nozzle issue?
 

18:1 shs gears
m120 spring
mask p head
shs poly piston
9.6v NiMh
unknown nozzle
modify cut off
mid cap mags
shs high torque motor (the thing is wild)

Alright, all parts are new, compression is solid, however the gun cycles 1.5 times or 2 times on semi and on full auto. piston seems to stop where ever it wants really.. do not have a mofset nor can I get one soon enough for an event. Any solutions?


Also while mentioning it the nozzle is sometimes partway retracted and my mid cap tries to unload all my bbs into the feed one shot.. I'll have many fall out the barrel after one flies out slowly..

Use a hotter spring, short-stroke.
Weird that it would be doing that since you're using just a 9.6V nimh battery though, are you sure it's an M120?

Also - did you hook up your tappet plate correctly/

M120 right on the package, tappet plate is correctly installed.. its super weird with the 9.6v
also just double checked the motor is an "ultra"high torque SHS.

I have an m130 I can throw in it but I have to wait for my piston to get here tomorrow, this one got stripped out because of a bb jam.. the red prom hard bucking was too tight and the bbs werent being pushed out

Just use active braking. With just 18:1 gears, and especially only using an NiMH battery, you shouldn't have any issues at all with comm wear.

In my initial post i mentioned that i dont have a mosfet or have time to get one before an event. Unless you have something else in mind?

I don't have a solution for you but that seems very strange, on a 9.6v

Does it take the same time to stop in full auto?

yes.

9.6 mini or large?

Do not use braking, it is bad for motors. Take your cutoff lever, and bend the arm up slightly to make it cut off sooner.

large. haven't used the small yet.. I have an 8.4 somewhere.


even when I manually cut power there is a lot of inertia left I'm wondering if its actually pre engaging.

pre-engaging is when the sector gear engages anything but the first tooth of the piston first. This always ends with a jam, or stripped piston.

If you're using a 9.6 large you'll want a mosfet anyway, and despite what pesto says, heavy wear does not occur in every scenario of active braking. Just like higher amperage motors wear out faster than low amperage motors, active braking kills higher draw motors faster than lower draw motors.

PTW's use high rpm motors on a 25:1 gearset and still go 3-6 years before needing to change brushes on an 11.1v lipo
my 249 ran a ferrite magnet motor on 26:1 gears for 4 years before the comm became so dirty it needed the carbon brushed off. And it still worked fine after. Also on an 11.1v lipo.

Unless you're running a high AMPERAGE (high TORQUE) setup, the comm will be fine.
voltage causes arcing, which causes carbon buildup. But it's AMPERAGE that causes pitting and actual damage.

We have very different experiences with braking.

I've seen braking wreck the commutators on motors in sub 20A setups as well. I had a customer's 20A setup fail every 30k rounds because the motor commutator would destroy itself and need to be relathed. I got fed up and got rid of the braking.

Braking doesn't seem to do much to ferrite motors, but they seem to do a lot to neo motors. I've never seen a PTW motor that didn't have comm wear that I would consider "extreme". My 50-60 RPS 30-45A setups don't wear commutators as fast as moderate setups with braking.

There's a difference between comm WEAR and comm PITTING
A motor can continue to run like new with extreme amount of comm WEAR
comm pitting is what wrecks it, requiring you to turn the comm

If you want to reduce comm wear, just use softer brushes. But then you're changing brushes more often.

Alright feeding issue is dealt with.. nozzle that was in there was an m4 nozzle, I needed an mp5 nozzle its slightly shorter..

Now I did notice this... I switched out to a shs piston which is apparently 1mm or 1.5mm longer than the stock TM piston.. swapped back to the TM and used a M130 and everything appears all good in the hood. Possible with the difference in piston length it changed my AoE hence stripping out the shs piston? (the first 5-6 teeth were stripped.. if it was AoE wouldn't it only be the first 3?) I didn't realize there was a slight size difference.