The overall cost of designing the driver that I’m using for the lathe still came in under the cost of what I was looking at for an alternative to building ( The KB electronics one was $100+, though I know you can buy the MC-60 treadmill boards on ebay and modify them for cheaper possibly ). It’s amazing how big those boards are, mine fits on a 2″x3″ circuit board and the number of components is drastically reduced – making it easier to fix if need be ( for me ).

My main problem with Mosfets burning out was primary due to heavy load, or stall situations, where the Motor was pulling as much current as it could ( most likely many times more than the fet could handle ). If I was to design another driver like this from the start, I would do it right and add ‘Currently Limiting’ from the beginning. It took me quite a few iterations of the driver to get it right, but at this point I haven’t blown another mosfet since adding ‘Current Limiting’ to the driver / controller. I’ve also been able to use cheaper mosfets which is an added bonus.

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That being said, most people I have talked to, that have used treadmill motors, either uses the MC-60 ( or equivalent ) board from the treadmill themselves ( or sourced on ebay ), or they buy a more expensive controller from KB electronics. Most of them simply add a pot to set the speed and that is it, but I really wanted to make a nice interface for my lathe with an LCD screen, etc, and I think I achieved that fairly well, and it might have been a bit more painstaking to try and hack together a bunch of different products and put them in the same box if you know what I mean.

Cheers,
Morgan

I have been doing a little reading and googling over the last few days. I was wondering if you had considered using a treadmill motor controller and/or display/input module, and if so why did you decide not to do that? You have made a few comments about burning mosfets, I wonder if using at least the motor controller would eliminate that, since it would be designed for the max power of the motor (assuming you found one that matched). Prices for controllers seem low on ebay. I am using the term “controller” a little loosely here, but I am talking about the module that both converts AC to DC and accepts a PWM signal from another device and applies that to the motor output. Some have more functions, like a tach or a temperature cut-off for the motor – you probably know more than me about all this, I just started looking. Anyway, I would appreciate your thoughts – Frank Spillman.

Cheers,
Morgan