Ok so I've built lots of CNC machines. I still have all of them. A First Mill, Bridgeport knock off - one of the best from what H&W says. Anyway, I've did my own conversion on that, jeez, maybe 15 years ago. A CNC lathe from a harbor freight machine - ok don't have this one anymore gave it to a friend. A CNC Router that I engineered and built from scratch, accurate as all get out. A CNC Plasma, again completely engineered and built by me. A 1978 Mori Seiki Lathe that I gutted and completely rebuilt with all new electronics and motors. I did all the programming and stuff.

Anyway, came across a variable speed head Bridgeport the other day and bought it cause it was a steal. I wasn't looking for it, don't need, but it was priced so good I couldn't go wrong. Looks in good condition.

So the First Mill I built I used 1200 oz./in. Stepper motors direct drive. I've never had a problem. I mean it's mis steps before when I screwed up and the end mill crashed and broke, but never lost steps from normal operations. Now I usually cut at 10 ipm as that the correct speed for most steel I cut.

So my question is:

Most people would recommend servos for the closed loop feedback, well now Automation Technologies, whom I've been using for decades, has closed loop steppers. The 1128 oz./in stepper and drivers are $209, the 1600 oz./in stepper and drivers are $299, but on Ebay I found some generic 1.5kw servos and drivers for $285.

So anyone have any problem with direct drive for the steppers?

Also, what would you do, generic servos or closed loop steppers?

I'm leaning toward the steppers so I can do direct drive which is way less time building the machine. I have the CAD for the same brackets I made 15 years ago.

But if I choose the servos I have to do a 1:3 or 1:5 reduction and that requires gears, belts, brackets and machining time.

Let me know your thought.

Similar Threads: