KSC HK33 blowing fuses
 

I have a KSC HK33A2 and it is blowing fuses like mad. The odd thing is nothing is broken or damaged in the mechbox. The gears turn freely and the motor still runs fine when pulled out of the gun. Also the gun can still be manually cocked and fired. I am a bit stumped on this one so any suggestions would be appreciated.

bad wiring or bad battery maybe

This happens in electric grinders, the shaft in your motor could be bent causing direct contact inside, making the fuse blow. Try a different battery first. If you need to get a new motor, a TM EG700 is a good choice.

tried 2 batteries, same thing. If the shaft in the motor was bent I would think this might make a distinguishable noise when the motor is run externally wouldn't it?

the motor runs fine externally off of the guns wires so i think the wires are ok.

What size fuses are you blowing?

15A and a 30A fuse

Your motor may run perfectly fine when it's not under load. But it may blow fuses as soon as you apply a load, even a small one.

Measure the current the motor draws with a DC-capable clamp meter or with an DMM rated for at least 10 amps DC in series with the motor. No-load readings in excess of 10 amps means your windings have a short from 1 pole to another. This often occurs at the crossover points at the poles ends, as the windings are pressed against their opposite polarity winding.

It requires you to remove the rotor and pull the windings apart just a bit at the pole ends. This is not for everyday Joe to do, and it's easier to buy a new motor.

If you lack the proper diagnostic equipment to perform simple draw tests, just buy a new motor. But it in-fact may not be the motor (less likely), so you will have to take a chance.

It's highly unlikely that the battery is the problem here, and it could easily be eliminated as a potential problem with a DMM.

Other sources could be motor position, motor height, chafed wiring near pinion gear.

thanks for the explanation. I do not have these diagnostic tools at my disposal but I can get my hands on another motor to test this theory.

The wires look fine all the way around so I dont think its that. Also with the KSC HK33 there is no way the motor can be out of position, its either in or its out. KSC built it so it has only one position it can sit in.

thanks for the help, it was the motor.

I know this is a pretty old thread, but out of curiosity what motor did you replace it with? Any standard short type will do? Looking to replace mine currently.