Finishing my CNC controller

Ok, I know I said I would start this several months ago. But the fact is that I’m beginning just now… and the first task I need to accomplish is to finish my long-delayed cnc controller.


I build this thing around three years ago. The chassis (11″x9″x3″) was a from an old optical reader; I love it, it’s very high quality (it’s nice to bring new life to scratch). The motor drive was the STK672-050, a Sanyo 3.0 Amp unipolar stepper drive. I did use 6 pin mic connectors, they are pretty cool. I got the 5 volt supply from a cell phone charger. Currently It’s a 3 axis controller, but there’s room for another axis if needed.


Please note I’m aware that bipolar driving are the preferred choice for cnc equipment, but I’m confident this will do the work. Supposedly one advantage of unipolar over bipolar driving is better torque at higher speeds (look here). My choice was driven mainly by availability of this driver years ago. Now chinese TB6560AHQ red boards seems to be a better option (after reading this, I realize first generation boards where a pain in the ass); in fact, I plan to order one of these for backup and/or testing.


This controller works very well (fast movement, not strange* noises, hard to burn), but I need to remake the pcbs due to a positional error, and after that, I need to mount the heatsinks and finish some details. So I need to start cutting some pcb board… guess have the perfect tool for this :D.

* No strange noises, but the typical noise when idle.

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  1. hi friend,
    well done it seems clean job, i want to learn did you compare with allegro a39xx series drivers which each axis provides 2.5A but the stepper speed is up to 900rpm

    1. Thanks. Well, all my motors are 3.0 Amp., so that limits somewhat my options. Regarding speed, I guess that depends more on the inductance of the coils (the lower, the better). Anyways I’m planing to use Allegro A4983 board from pololu for another cnc projects I have in mind.

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