CA m15 motor issues?
 

got a CA m15a4 in for a friend today. hooked up a battery, and the motor turns, but gun doesnt fire. so i turn in the set screw, and nothing works.

I start dissassembly to find the problem, and the motor is jammed so far up the grip, i cant pull it out. motor issue fixed. BUT, now it doesnt work at all. I can hear the motor begin to turn, then lock up.

make shure that its set right, and that the gears wernt dammaged,

and i know this sounds like an idiot question, but did you make sure you put the leads back on correctly?

the red goes on the + side

Mechbox could be locked up... if thats the case im surprised you didn't blow a fuse yet.

hell only blow the fuse if hes stupid enough to hold the trigger for more then a second

It isn't hard if you give the trigger a couple pulls to test it out each time. Anyways thats beside the point. Crack your mechbox open if you're comfortable doing that kind of work.

well... this gun is a barrel of fun. Among the stripped threads ill have to re-tap later on, the wiring is backwards. the battery plug had the wrong shapes on the wrong sides. brilliant.

not for CA guns, or echo1, at least in my experience

its the only 2 brands me and my friends have, so

your right. never as an electrician for advice :)

Now, it cycles once, then locks up.... the situation is slowly turning good. any suggestions?

Just an update: this thing is alot of fun. Ill have to replace all the wiring inside the mechbox, its full of stripped insulation. It has temporarily been shrink wrapped.

Shimming was horribly horribly done. Ya, the gear to gear placement was nice, but the gearbox to gear ratio was horrible. i could barely squeeze the mechbox together with the gears in, and the gears barely moved there was so much pressure on them. it has been reshimmed properly.

Gearbox is still jamming up at the spring's most compressed position. It was suggested that an aftermarket spring was installed that was too long, ill be swapping out the spring/cylinder assembly to test that theory.

how long is it? cuz i dono how a sniper spring would even fit in it,

it still could be shimming, how many shims did you use, if its over 8 its prob to many, theres only 5 in mine

its probably not the spring, but rather the travel of the spring is too short. my bet is on this funky spring guide, nothing like ive ever seen. ill try to dig up a picture of it. it has a huge plastic "bushing?" on it, takes about 1/4" of space away from the spring, enough for me to assume the spring reaches its full compression before the gears can rotate enough to the last tooth, thus jamming. I dont have a regular v2 spring spring guide to test this theory.

Can anyone confirm that CA stock spring guides do not have a huge-ass cylinder surrounding the guide? Anyways my bets on that.

Shimming I may check again, although im pretty happy with it as ive rearranged it.

Dude, I just saw this post...I've got a complete stock CA piston, cylinder, spring and spring guide for an Mp5.
I replaced the stock internals with a Hurricane 120 upgrade kit.
You're still going to FNG day tomorrow?

G&G used to make a black spring guide with round steel tabs to lock it in the mechbox shell. They used a plastic spacer about 1/4" thick, made out of the same black plastic, most likely ABS or similar polymer.

Kev: ya ill be there. ill bring the m15 just for kicks.

Mcgyver: sounds like thats the win there, pretty much exactly describes it. G&G and CA probably dont mesh together 100%.

take the plastic thing off, but it should have worked anyway. my CA got upgraded by someone else before i learned how, a long time ago. so i don't have any info on what its supposed to have, but mine now just has a thin piece of metal, the thickness of a shim, around the guide, and it works just fine

Just an update:
It works!!

I want to extend a huge thanks to Kevorkian for hooking me up with the correct stock CA internals. It most definetly was the spring guide, as the correct one looked nowhere like the one that was in the mechbox. A little bit of work and time and this gun will be up and running very well!

PS: i broke the spring to the anti-reversal latch... I remember there was a thread debating the need for the latch. Is there any repercussions for going without it for a long time?

I had something like that happen but It just turned out that the hop-up was cranked to far :D

I've got a spare spring kit for a complete mechbox...if you're interested!!! BNIB !!!

oh the irony! i broke the anti-reversal latch spring! ill take it!

there is no additional damage in not having an anti reversal latch, but when firing on auto, after firing you hear the spring push the piston forward again, spinning the gears backward, making an annoying noise.

It is annoying, very much so. either way i hope itll be good to game by sunday, maybe i can take some friends to black mamba... we need more insurgents.

i think i have an extra spring laying around, would you like it?

well... i did have it all back and working, now i have electrical problems, its shorting out.... this is really really pissing me off!!!

how do you know its shorting

connect the battery, motor and everything, pull the trigger and nothing shoots but the wires and battery get very hot. The wiring on this thing is the shits. insulation is cut everywhere, so im really not surprised, i was just hoping id get away with not having to replace the wiring.

I've got a stock trigger/switch assembly????

i think once i get new wires and get everything nice, ill take it to a gundoc to assemble it nicely.

if it was a short, wouldn't it be getting hot before you pull the trigger?

does your motor buzz?
and check your trigger tabs, the ones that touch the selector plate, make sure they aren't touching.

no motor buzz, its possible its in the trigger.

I have no experiance with v2 mechboxs. all my experiance is with the v3 with, in my opinion, a much more simple trigger mechanism.

I know it must be me, since i had it firing on full auto. Its only when i took it apart to fix semi-auto that these new issues occured.

but v2 and v3 are similar, and from this point id just send it to a gun doc

Just an update:

short was found and repaired, was in wires, so no biggie. Shoots full auto strong and straight. very good performance.

semi auto still not working. by checking continuity, i have connection for the last half pull of trigger on semi auto, followed by an audible *pop* (defiently a spring) then a loss of connection on the last bit of travel of the trigger.
Connecting the motor to the gearbox and battery produces like results: motor engages at the 50% trigger mark until at about 90% trigger, where a spring sound occurs and the power is cut. Fully assembled, the cylinder doesnt budge, no signs of motor turning over, but audible pop is still there.

Mostly, I know this is a trigger mechanism improperly assembled. (by me or previous owner, who knows!) Or perhaps broken. Does anyone have a detailed diagram of a v2 trigger assembly, focusing on how the indiviual parts work together in semi- auto use?

theres only one spring on the tirgger mech, and it deals with the retraction of the contact, so i dont know if it is the spring your hearing, unless it slipped off

lets see if i can describe it verbally.

there are the two trigger contact parts, and then on the one that is mobile, there should be a spring from the top of that to a post a little behind it.