I have an Amadeal XJ12-300 mini mill, bought used.
I took off that spring thing and fitted a gas strut, then fitted three DRO's. It was the bees knees, I thought. But I was truing of a hole using an 8mm end mill as a reamer, I went too deep, the end mill jammed and teeth flew everywhere.
I bit the bullet and ordered a belt drive upgrade kit from Amamdeal, Great service, ordered it on Sunday through EBay and had it fitted on the milling machine on Tuesday morning. Wonderful, for two days 
It started kicking and farting with a grating noise from the top end, I thought that I had pulled the belt too tight and knackered the bearing on the motor, so took off the end cap, and the bearing on the pulley end looks and feels perfect. I ran it under power and it still kicks with no load on it and every time it kicks there are blue sparks from the brushes. If I turn it by hand there is a slight squeaking noise from inside it.
Now I know next to nothing about electricery, is the motor caput or is it the circuit board, and where is the best place to get replacements.
Edited By John Durrant on 14/08/2014 16:22:36