The Shop > Tools
micro mill electricals problems, help please!!
Stilldrillin:
And? :scratch:
Awwww....... Come on! It's my bedtime!
David D
steampunkpete:
I can't stand not knowing any more, the bells, the bells, the sand, the heat, the flies! :loco:
DOES IT WORK?
pmdevlin:
sadness abounds, and here is the proof.
yi9-g
so, at first all is well, although a lot of "pot" movement before anything happens. When the first fuse blows, the motor emitted a big spark at brushes end. I did note when running, it was like having a small misfire in an engine, it wasn't real smooth. It was noisier than before, however the belt was slack, and I don't know if it was on the correct pullies at this time.
You can see what happens after that. I have put a 60w bulb on the output of the control board, its gone back to how it was prior to Johns repair (real sorry John, I wanted it to work as much for you as for me!). With pot turned off, bulb is very bright, turn up pot, brightness stays constant, John tested this and he has a proportional brightness with the pot.
So back to square one unfortunately, and I have probably blown Johns repair, however, I can solder John, and thanks to you sending the part back, could probably change it out again.
So peeps, I don't know what is the cause, change motor, its not motor and keeps blowing board, change board, and its the motor??? I stripped motor again, cant see any sinister goings on.
I am thinking change the thingy John did, and the pot? try again, hopefully the video will give up a clue, now where is the thrashing thing, this machine needs a dammed good John Cleese style thrash :D
PS..., Just watching video back again, when first turned on, you here the motor, but see its not turning, so no real slow drive, then up to 0.34 you can here the speed isn't exactly constant. For reference, when it first went bang last year, fuse just blew, I had slowed the motor down
John Rudd:
Sparking from the com like that is indicative of either an adjacent short or open circuit.......there should be little or no sparking....assuming the brushes are in good nick...
So, to the controller,advancing the pot quite a way before anything happens points to the motor...(I'm not trying to exhonerate myself here... :( ) the lamp I used lit more or less straight away...albeit at reduced brightness, which is what you'd expect...
If you attempt a repair, unscrew the bolt securing the heat sink to the mosfet(an IRFP450 you can get them from Ebay at reasonable cost), remove the heat sink from the board, then cut the mosfet legs with side cutters, then remove the remains from the board gently.....don't overheat the copper pads on the board else there's a risk of it delaminating.....reassemble, test with a lamp bulb to see all is well....decide what to do about the motor...
lordedmond:
That motor has released its magic smoke :zap:
As John said its looks like a short , windings or comm I cannot be sure.
If it was me in your place I would repair the board as per Johns post and get a new motor .
Stuart
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