Hi Doddy

I'll be wiring the transformer for 36 volts, I hadn't thought about the upgrade to a 4th axis. I'll use a heatsink (they aren't so expensive and fix it to the case ) I'll have a look at the thermistor. I'll be using a couple of fans in the case for good cooling. My old control box has a switching power supply and for some reason the inbuilt fan in the power supply really gets on my nerves with the noise it makes.

Cheers

Andrew