help with extreme rof

[SAS Scott]

So I basically made a rof beast up but every time I go onto full auto it strips the entire piston (except the first metal tooth)

I know its not
AOE
shimming
swiss cheesing
as I have all these perfect .

setup
acm p90 gb
element 7mm bearings
element max speed motor
deans
16 awg wire
gear clip
ca proline tappet plate
modify piston head
modify spring guide
modify air nozzle
m90 spring
ca proline cylinder head
jg crome cylinder (porter correctly)
element light weight piston (with 2nd and 3rd tooth removed)
Prommy cut off lever
ca proline contacts set
9.6v battery.

So I think its the piston not returning in time and the gears just shred the piston

I have tried the same piston one modified and one standard but it still happened.



Would anyone know how to solve this ,I was thinking about short stroking the gun and maybe a mosfet might help.

Thanks for your help and time.


Ps battery was only half charged 0.o. and it was fired with the gearbox out of the gun .

[Clot]

Re: help with extreme rof

M90 spring is FAR too weak for a high speed setup.
Its not returning the piston quick enough.

You want to get an m100 minimum in there, if necessary, short stroke it down to reduce fps slightly.

[Montesa77]

Re: help with extreme rof

+1 to that clot.

M110 and SS a few teeth.

[SAS Scott]

Re: help with extreme rof

M90 spring is FAR too weak for a high speed setup.
Its not returning the piston quick enough.

You want to get an m100 minimum in there, if necessary, short stroke it down to reduce fps slightly.

Ok thank you ,will order one tonight and I think its an m90 as it give m90 fps .
or does anyone know what spring standard acms take.


edit I know how to short stroke but does anyone know whats the max teeth you an take off the sector gear and the front of the piston?

[Montesa77]

Re: help with extreme rof

9-6 I guess. Just remember to take them off the right side.

[SAS Scott]

Re: help with extreme rof

9-6 teeth but that will leave near to none left and i do know that side to do them on i have short stroked my mp5 but only just to learn .

[Montesa77]

Re: help with extreme rof

So, just use a massive linear spring.

[SAS Scott]

Re: help with extreme rof

I know this might sound stupid but if i have a hot gun could I just make the air seal worse so I get less fps as I have heard some high rof guns dont have good air seal on the piston heads so they get higher rof .

[Montesa77]

Re: help with extreme rof

Yeah, but it could affect the shot consitancy.

[SAS Scott]

Re: help with extreme rof

Yeah, but it could affect the shot consitancy.

Oh ok that will be a last resort to get it under 330 then .

[SAS Scott]

Re: help with extreme rof

ok this thread will be updated in about 2 weeks (when parts come) to weather this has worked

[Montesa77]

Re: help with extreme rof

If its over 330 just take some more teeth off. What length barrel are you running?

[SAS Scott]

Re: help with extreme rof

stander 247 but it will soon be upgraded to a madbull tp barrel still 247 mm
it will also have tm hop unit ,fire fly rubber and fire fly nub.

[Montesa77]

Re: help with extreme rof

You could go to a MP5k cylinder to aid the piston coming back and forth. When you SS don't go so far that the piston doesn't reach the port though.

[richardy]

Re: help with extreme rof

after market cyclinders, nice ones have a teflon coating they help reduce friction increasein return time.

Smothing out the railigns is popular to help speed up the return time of thepiston..

Its definatly worth remvoing the gears and spring and clsoign the case back up and trying to test the movment back and forth of the piston in the casing..

You need smooth effortless operation... Just like youd pay attention to the shimming, you neeed to check the "shimming" giant airqoutes, of the piston, tappet plate, air nozzle.

Check how the gear connects with the piston you want to make sure that if it is a half tooth job its not touching it on one side slowing down its return time.

Basically this is the extra stuff which techys like too talk about when they say "fine tuning"

Try and locate all the point of contacts on the piston during the return process and make it smooth.

To meet the middle of the piston is uslaly more than simply a weak spring..

Which can be over come...