Hi all,

I've had a Interact 1 Mk2 milling machine for several years, and it's (mostly) been fine. However, after a long lay up, 18 months, it blew a capacitor on the KTK drive thyristor board. Well.. I say "blew" - it caught fire.... I've replaced all the caps on the THY-1 board, but now it's popping the main supply breaker almost every time I try to start the spindle; and if I do get any life out of the spindle, it's only a few rotations before it stops. And I think it's going backwards.

I suspect more damage somewhere else, but I have very little knowledge of how the drive actually works. Replacement KTK Thyristor boards seem to be unobtanium, and the top control boards are ridiculously expensive (although I think mine's OK, I'm pretty sure it's the thyristor board that's toast).

So - my question to the knowledgeable here: Is there a sensible alternative (i.e. NOT priced at £2k+ - this is a hobby machine, and I can't afford that sort of outlay on a machine that's otherwise full of 40 year old electronics/wiring) to the KTK drive? Is there any other way of driving that BFO motor?

Everything else seems fine - the machine references fine, the axes all move fine, coolant comes on/off... I just can't get the spindle to spin.

Thanks in advance!