Unipolar/bipolar

[mocnc]

Once again.....I am probably going to ask an other dumb question that I should know the answer too. I tried a search on here and couldn't find my answer, so I am once again hoping that you bare with me and help me out. What is the difference between an unpolar and bipolar stepper motors and boards? What are the pro and cons of each? I have purchased the hobbycnc 205 oz.in 23-205-ds8 (8 wire) stepper motor. From what I can see/read that it can be hooked up either way. So I guess before I get my boards, I would love to know which way I should go. Also, does anyone have the wireing colour code for these steppers?

[dertsap]

hobbycnc is a unipolar board , you can only run unipolar motors , on a bipolar board you can run bipolar or unipolar motors , hobbycnc has a user forum that you can go to in order to get the proper help to connect your setup

[steve323]

The motors will produce about 40% more torque in bipolar mode, but you will need a bipolar controler board instead of the HobbyCNC. The HobbyCNC board is a great unipolar board. The Gecko 540 appears to be the favorite bipolar board.

The HobbyCNC web site should have wiring diagrams for the motors.

Steve

[hgk]

stepperworld.com has good tutorials on uni and bipolar motors which will answer some of your questions.

[Crevice Reamer]

Your motor is 8 wire, so can be wired in ALL 4 methods. It will produce best power at 48V wired either Bipolar Parallel, Unipolar or Half coil. It will draw 3A and produce 205 oz in. of torque in Unipolar. It will draw 4.2A and produce 285 oz in of torque wired BPP.

There are 2 Phases of 2 coils each in most stepper motors. Bipolar motors use both coils in a phase at the same time. Half coil uses one coil at a time, and reverses direction using the same coil. Unipolar uses one of the two coils for forward direction and the other coil for reverse.

This is covered in my Basic CNC Primer under stepper motors:

http://cnczone.com/forums/showthread...709#post572709

CR/