I've done a very stupid thing

Spetzcong

So, I decided to try and install a downgraded spring in my cyma 0.28S Ak-47S. All went reasonably well until it came time to open up the gearbox. By following the instructions on mechbox.com I finally (with great difficulty) got the new spring installed and the gearbox back together. Before I went to put the rest of the gun back together I decided to plug in the battery and see if everything was functioning, the AEG made a sound like it was trying to fire and then died and smoke started coming out of the battery :eek:

Decided to test another battery in it (never been one to learn from my mistakes me) and low and behold the same thing happens, only this time I can see the fuse getting totally fried. Not having a replacement fuse I had to call it quits, so here's some questions for you more knowlegeble airsofters. What do ya reckon caused the blowing of the fuse and burning of the battery? Did I muck up the electrics when I was tinkering around in the gearbox? Could it be something as simple as me having touched the fuse/wires with greasy fingers or do you reckon I've totally wrecked the electrics? Where can I pick up a new fuse? I'm gonna try some electric stores tomorrow, but if anyone knows of anywhere it could save me some looking.

Before I finished in the massacre of my beloved AEG I thought I'd try and put everything back together so that I don't lose any of the tiny screws. Unfortunately I found myself to be completely inept at getting the fire selector switch reassembled, I took pictures of where it was, and can get it all alligned properly before I try and slide the gearbox back into the body of the AEG, but as soon as I try to get the gearbox back inside it all goes to sh*te, any tips?

I think I've learned my lesson about trying to tinker around inside my AEG with absolutely no experience, horrible way to find out you're useless at something though, to be honest I'm not sure I'll ever get the thing working again, but I'm sure gonna try.

Fiach Dubh

Sounds like a short circuit. Check all the wiring closely and make sure the insulation hasn't been damaged anywhere, if the copper wiring is showing and is touching the gearbox you'll get smoke like that and the battery will heat up rapidly. Also check the crimp connectors at their terminals and make sure there isn't any damage.

Skatedude

the gears may be jammed,can you remove the motor and try to turn the cog in the gearbox that te motor connects to? just use a screwdriver to see if you can turn it a bit at a time.

Taking apart the gearbox is the only way to learn how to take apart the gearbox, you will get the hang of it after a while, and possibly a few new gearboxes

Spetzcong

I checked that the gears were moving before attaching the battery, the gears all seem fine, it seemed more like a short circut to be honest, it sounded more like the AEG just ran out of power rather than the gears running into resistance, also the sparks and smoke from the battery. I'll get myself a new fuse and give it another go tomorrow, I suppose I can mess around with it a bit now, if it doesn't work with a new fuse in it then I guess I'll have to take the gearbox apart and start over. Well I've nothing to lose by trying now I suppose, I'm AEG less till I either get this one working or get myself a new gearbox for it.

CrazyRabbit

Double, and triple check the wiring. Almost certainly a short circuit.

As for the fuse, well you don't actually need it. It can be bypassed, but make 1000064% sure that you've fixed the cross circuit first.

kdouglas

it's best to keep the fuse either way tbh, should something go wrong, it means the cheapo fuse will blow instead of your motor and/or battery

as everyone has said, most likely a short circuit

cant say for definite about the fire selector, but if it's like other ak's i've seen (where there's a little gear mechanism for the selector) it shouldnt be too much hassle, post a pic of the selector assembly and we'll see what we can see

Spetzcong

Thanks for all the advice, I've managed to get everything working again, picked up some fuses at lunch today but I still had to reopen the gearbox, turns out I'd forgotten about the spring which holds the part of the AEG which completes the circut when the trigger is pulled in place. I just had the circut complete the whole time, no wonder the fuse blew when I attached a battery

I also managed the fire selector switch, well kind of, I no longer have single fire, just safe, full auto and full auto. I really can't face opening everything back up to fool around with the selector gears though so I'm gonna leave it like that. I've got a drum mag on order so I suppose I can justify it as some sort of folding stock RPK hybrid monstrosity. I'll need to get myself a back up for CQB (because full auto at close range is a bit much) but that's just an excuse to buy more stuff so I'm not really complaining (the bank balance might though).

Fiach Dubh

Good to hear you got it sorted. You may want to consider fixing the fire selector though as after a days shooting you should fire a couple of shots on semi to loosen the spring tension.

There's no problem with putting a drum mag in an AK47, RS AK's can take them so you don't need to make any excuses