Denford Novamill Mach3 conversion

**Miller** · 19-10-2014

No worries Eddy, and thanks everybody especially John. The circuit looks easy enough, I should be able to test it sometimes next week.

Alternatively, I have found an off the shelf converter from Axiomatic:

http://www.axiomatic.com/TDAX13020X.pdf

But I have a feeling it's going to be much more expensive than the diy version John proposed, so not really an option.

On another note, can somebody confirm a 24-28v 10A power supply would do, and what voltage do you feed to stepper drivers?

**JohnHaine** · 19-10-2014

Hello Miller,

Let me know if it works and any questions.

On the PSU, the one I use in my Novamill conversion is similar to the 36V one here: but I got mine direct from China via ebay for rather less money IIRC. Look for topengineer1989 as the seller. I use the common 2M542 drivers. 36 volts is fine to drive the steppers assuming the drivers are rated up to 40 or 50 volts. I think I have set the X and Y currents to just less than 2A and the Z probably 3 but could check those.

John.

**Miller** · 19-10-2014

Yes, that's the seller I bought the BOB from. It came as a complete package with 3 x 2M542 drivers. Still in the post but should be getting it quite soon.

The motors are rated 1.5A and 3A at 30V, so I will keep about same amp rating and feed 36V then.

What I had in mind for power supply is this. It shouldn't make more than £30 posted and looks nice quality and DIN mounted, but if it's less than ideal because of the lower voltage, I'll go for the 36V as you suggested.

Just to confirm, your circuit has 2 x 470K and 3 x 47K resistor. I have selected this for C1, and this for C2, and this for the op amp.