TB6560 + Vexta PK266-02A

[maltamirano]

Hi everybody!
I'm a CNC newbie wanting to build a foam cutter. I have very little knowledge of eletronics, but a strong will!

Already bought some parts...
-TB6560 4 axis driver board (3A stepper drivers)
-Vexta PK266-02A 2 phase steppers (6 wires)
-24V 14.6A 350W switching power supply

...which I would like to test.
I guess the power supply is OK, but I'm not sure how to set DIP switches 1 and 2 (current) correctly for my steppers, and don't want to blow something away.

According to the stepper .pdf specs:
Current/phase = 2.0A for unipolar and 1.4A for bipolar.
Same specs recommend 24 Vdc 2.8A for bipolar and 4.0A for unipolar.

This is when I get confused, when trying to calculate current for driver settings:
a) Current = Current/phase * phases ? (4A unipolar - 2.8A bipolar)
or
b) Current = Current/phase ? (2A unipolar - 1.4A bipolar)

If answer is a) then I wouldn't be able to provide 4A because the driver supports 3A max (supposing unipolar connection)
If answer is b) then I would be OK with the driver current output, but should set DIP switch accordingly. In this case, I can only set 100%, 75%, 50%, 25% of 3A, which gives 3A, 2.25A, 1.5A and 0.75.

What setting should I use? 2.25A? 1.5A?


Perhaps I'm missing other information relevant to my question. If so, feel free to ask.
Any help will be appreciated.

Regards,
Martin

[H500]

Answer is b. But try using the bipolar half coil configuration and set the current to 2 amps. It will likely give you higher speeds.

[maltamirano]

Thanks for your answer.

Using bipolar (series) connection the current requirement will be 1.4A, so setting 2A will not burn anything?
Nearest setting through DIP switches is 75% * 3A = 2.25A. Will this be OK?

Regards,
Martin

[H500]

Bipolar parallel at 2.25a should be fine. If the motor is mounted on metal, a lot of heat would be conducted away. You could also use a small cpu fan if the motor gets too hot.

But don't put 2.25 into bipolar series. The motor will overheat.

[maltamirano]

Now I'm even more confused...
Specs at http://www.interinar.com/public_docs/PK266-02A.pdf say nothing about bipolar parallel connection. Only unipolar or bipolar series.

Is this possible?

[H500]

I actually meant bipolar half coil. It has the same current rating as unipolar.