p90 semi fire problem

[solidgear34]

so i got a ca90 pro line and after some small tests i noticed that on semi auto if you pull the trigger too fast repeatedly that motor/ piston will jam and all i can hear are the motors attempting to pull the piston but to no avail... is there any way to fix this? i really do need a fast firing p90

[iKliiu]

What battery are you using? This sounds semi-auto locking.

[lurkingknight]

definitely sounds like semi auto locking... you need to fully pull the trigger and wait for the gun to cycle before pulling again to avoid this. What's going on is you're partially cycling the gun and it will stop somewhere in the middle of the cycle where it usually requires a lot of power or torque to turn over and pull it off this spot. A full auto burst will sometimes unlock it for you. Sometimes on a p90 it will mechanically jam the trigger device on the cutoff lever so it physically blocks it from being able to close the circuit.

You can't fully eliminate this problem, my p90 with amazing trigger response will still lock up from time to time.

You can make it less of an issue... there's a few options...

First is more efficient power delivery... lower resistance wire, better fuse setup or no fuse at all. A simple mosfet will also create better electric efficiency/delivery. This will increase auto rate of fire.

You can put a bigger battery on, higher discharge lipo or higher mahl nimh... this increases rate of fire... increases wear on trigger components without a mosfet.

You can put in a faster/higher torque motor... shs, jg blue, element, lonex... any neodymium magnet motor. This drastically increases torque and rate of fire... lower power springs might self destruct your piston.

You can put in a lower ratio gearset... so the gun mechanically completes a cycle faster... this increases your rate of fire.

The problem becomes that when you put all of this in... you get ridiculous rates of fire... but super short trigger response... in fact.. you get disgusting rapeworthy rate of fire if you know what you're doing. For most people that's too fast.. talking in the 30-40 BBs a second out of the front of your gun.

You can get into specialized expensive mosfets that control your rate of fire and retain your super fast trigger.

But you're looking at an extensive list of upgrades at that point, not to mention really specific tuning so the gun doesn't assplode on itself. Lots of supporting reliability mods need to be done if you want that kind of fast trigger response. They're not hard to do if you take your time to read up and do them, but not everyone wants to do that.

There's not much you can actually do if you leave your gun as is to fix it... just complete the shot before pulling the trigger again.

[solidgear34]

well what i run is a techenergy 8.4v maah battery. though i don't know what battery options work for the p90. i, don't really want to change anything in the gearbox so im wondering what motor / battery do you guys use to eliminate the problem completely?

[Short Round]

I run a 7.4v Lipo and a G&P M120 High Torque Motor

For a P90 that fires fast on Semi though your going to have to re-work/upgrade you gearbox. This would include switching to deans, a mosfet, prometheus trigger arm, new motor, and a lipo (either 7.4v or 11.1v)

[solidgear34]

i was hoping for a 9.6v and a new motor... wondering if that will be decent enough

[Short Round]

Originally Posted by solidgear34

i was hoping for a 9.6v and a new motor... wondering if that will be decent enough

New motor will help, switch over to deans though if you have not already.

A 9.6V won't really do anything though.

EDIT well actually a 9.6v would be better then a 8.4v but a Lipo is your best bet

[solidgear34]

i see, i don't think i can change to deans... i suck with wires. and my budget is killing me alive since i already invested in a REM-T3

[solidgear34]

i might go for a new motor though, what would you suggest that might make the piston more responsive when i pull the trigger multiple times?

[iKliiu]

Yeah, but it also destroy your piston if it is not setup properly (AOE correction, PE). Another helpful part for semi locking is an AB mosfet, but that wears your motor brushes down quicker.

[Short Round]

Originally Posted by solidgear34

i might go for a new motor though, what would you suggest that might make the piston more responsive when i pull the trigger multiple times?

What Lurkingknight suggested pretty much covers it all haha. He knows what he is talking about, he for sure has more experience with P90's internal then I do. Whatever he suggests is what I suggest (he reads my mind before I can even post 90% of the time)

He is right though, your gun will lock up on semi not matter how great it is. I have a pretty decent one (will post video tomorrow showing my semi), but my gun will lock up from time to time, its just how the thing was built.

[solidgear34]

ohh boy... i dont get half of this stuff...

[lurkingknight]

gots to start reading somewhere...

AoE (angle of engagement) correction and shimming are probably the most important factors to a reliable gearbox whether it's shooting 12rps on an 8.4v battery or 50rps on a dsg monster. Smoother turning gears create less resistance and allow the gun to function more efficiently.

If you don't want to mess with lipos since they require a bit more attention to upkeep, a 9.6v L battery build for p90s will be better than your 8.4. They cost around 30-40 bucks. That and a wiring upgrade are probably the first things you should try to help your issue, but you need to slow down your trigger pulls and make sure you pull completely rather than halfway. It's really the only safe bet to not encounter the semi lock issue.

My gun fires in a matter of milliseconds, I can still lock the gearbox with really fast semi auto trigger pulls or if I try really hard. I can pull the trigger faster than the gearbox can cycle, even at 30rps so you'll never eliminate the problem completely.

this is what 30rps sounds like My m4 - YouTube I don't have video of my p90, nor do I currently have my team chrono to show and measure exactly.

note the trigger response on semi. This guy used a different combo of parts to achieve this number than I did. Not to mention running a hotter spring. Even with a trigger pull that fast, I have locked up my p90 a few times in one game, so it doesn't really matter what you do to your gun, it WILL lock up if you don't let the mechanics finish doing their work before letting the trigger go or pulling again. Shoot, full cycle, shoot again.

It's a problem with AEGs that you have to live with. A new high power motor like an SHS high torque or lonex A1 will do it for you, but the lonex is closer to 60$ while the SHS is maybe 40. While I have not tried G&P motors, I can't justify spending the same amount on an older ferrous magnet motor rather than a newer higher power neodymium magnet motor. Look at the price of the guarder extreme torque up motor vs lonex A1... 85 vs 60$ and the lonex can pull a much stronger spring with more power efficiency at a higher rpm. More torque, more speed, less money.


Also, for all intents and purposes, most 7.4v lipos will perform similarly to a 9.6 but in a smaller package. Not exact, but similar. Power delivery is completely different. I ran my p90 before all the upgrades on a 9.6v nimh at about 16-17rps on stock gears.