[obscurity]

I have read somewhere on cnczone that you can drive 4,6, & 8 wire steppers with a bipolar drive (L297/298 in my case) but not a 5 wire. Last night I hooked up a 5 wire stepper to one of my driver boards and it worked. I left the center tap unconnected.

Now it was not in a machine set up since my table isn't complete yet so it may not have had good torque or I may have been slowly destroying the motor or the driver.

I guess my question is should that have worked and can you drive a 5 wire stepper with a bipolar drive and expect reasonable performance from the motor?

Thanks
John W.

[pminmo]

You can make a 5 wire step with a bipolar driver, but don't expect it to operate correctly over hundreds of steps and direction changes.

[jeffs555]

You could also damage either the motor or the drive.

[RotarySMP]

I think you are confusing five phase steppers and five wire steppers. A five phase stepper can not be driven with a bipolar driver. A five wire Unipolar stepper can be driven fine with a bipolar driver.

[jeffs555]

Mark,
A 5-wire unipolar stepper cannot reliably be driven from just any bipolar stepper drive. The center connection between the two phases will cause problems with many bipolar drives. It might work with some simple full or half step bipolar drives if both ends of each coil are always switched to opposite polarities. However, to control current decay many chopper and microstepping drives at times only switch one end of a coil when chopping or even worse connect both ends together. On a 5-wire unipolar motor, this will cause current to flow through the center tap to or from the other phase coil and drivers. This would cause eratic operation and could exceed the current handling capacity of either the motor or the drive.

Read the data sheet for the l297. It is rather simple and does not include mixed decay modes like more modern drives. It describes the modes that are compatible with unipolar motors, but is capable of and does describe modes which are not compatible with unipolar motors.

Jeff

[RotarySMP]

Thanks for that info Jeff. The only time I have used five wire motors was with a simple halfstepping L2997/298 driver, as john was asking.

[venomx999]

The L289 driver seem to be the best compared to my *3axis-self contained www....still can't get it to work.

Troubleshooting a self-contain board is a pain in the ulcer

[pminmo]

Not it's actually really simple. But admittedly you have to have some basic understanding of how to make a dc voltage measurement, a continuity reading, not install chips backwards, supply a dc voltage and read and answer a question. I will make this offer, send the board to me with a return package and costs for shipping it back to you, and if the board is in good enough shape to get it to work, I will fix it at no cost unless I have to buy some parts.

[pminmo]

Looks like your motors are 6 wire motors so they can be run either uniploar or bipolar:
http://www.mitsumi.co.jp/Catalog/com...fo/text01e.pdf

[venomx999]

Phil,
Sure I will send it to you. That is my best hope....

What is your addy ?
Ps: send to my email @ [email protected]