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Stepper Drivers.

The first stepper driver I used were "Single Step" drivers bought from Oatley Electronics. The K179 comes in kit form, very cheap and works fine for small stepper motors. To get the best results, the K179 should be used with a constant current source, and fortunately Oatley also sell a constant current supply in kit form.
The K142C constant current driver kit includes a fan cooled heat sink and easy current adjustment. I ended up building my own constant current supplies from scratch, but for under $30 each these K142C kits would make life a lot easier.

Useful Links  
>> Oatley Electronics
>> K179 PDF
>> K142C PDF including wiring diagrams

Transformer based power supply, with three K179 controllers and home made K142C current regulators

The K179 is what we call a single step controller. While a single step controller is fine for small stepper motors, if you want to get more speed and smoother operation, you need to invest in a half step or micro stepper controller.

I found my stepper motors would work fine at low speed, but became unresponsive at higher step speeds. To get more speed, I needed to spend more money.


Along with some larger stepper motors, I bought a couple of half step controllers from Ocean Controls, the KT-5191. The KT-5191 has half step stepping, and built in PWM current limiting. So a single KT-5191 would replace the K179 and K142C boards.

Half Step stepping made a big difference to my CNC table. Motor movement was much smoother and quieter.

The next step was microstepping. I had read about microsteppers, but they were priced out of my range, usually several hundred dollars or more per axis. One day while I was browsing the Ocean Controls web site, I discovered their new range of cheap microsteppers. The SMC-002 M325 was the cheapest at only $99+gst. The M325 has inbuilt current limiting up to 2.5 amps, up to 8 steps of microstepping, and would run at up to 32volts.

Useful Links  
>> Ocean Controls
>> KT-5191 PDF
>> M325 Microstepper PDF

When this photo was takes I was running the two AT power supplies, two M325 microsteppers ( X, Y axis ) and one KT-5191 ( Z axis ).


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