TB6560AHQ locks steppers when power applied.

This is for a DIY wood milling machine that I've been building. I'm using LinuxCNC 2.6.7 with the above mentioned TB6560 and NEMA 17, 76 in-oz steppers, but the issue with the TB6560 happens when I first turn on the power. The x and y axes are locked, i.e., I can't turn the motor spindles by hand. The z-asix I can turn by hand. When I fire up LinuxCNC and load a g-code example file and run it, everything seems to work fine. When the g-code program finishes the x and y steppers are locked again. This wouldn't normally be a problem except the steppers get a little too warm after a while of not being used.

I'm assuming this is an issue with the parallel port settings. Nothing I do in stepconf helps the situation. I can provide the .ini files if that will help.

Any help to solve this issue will be greatly appreciated.

Thanks in advance.

How hot? Yes, they get uncomfortable to touch. I used a Harbor Freight infrared thermometer to check the temp. The starting temp was 16.2C. After about 30 minutes it was 62.2C and still climbing. That's well done for my pot roast. Aside from the waste of power my general rule of thumb is that hot things don't last as long as cool things.

Thanks for all the comments till now. The problem I'm trying to resolve is to NOT have the steppers under power unless they are commanded to be under power. When I first turn on the power supply to the driver board (TB6560AHQ) some steppers are randomly powered on by the driver board, sometimes it's the x axis, sometimes the y-axis, and sometimes both the x and y axes. The z-axis has never been powered on randomly, yet. This happens when LinuxCNC has not been started yet.

Logically (to me) they should be set to an idle state (none of the stepper coils powered) untill LinuxCNC or some other software control program tells them to do something. After that "something" is finished they should be set to an idle state meaning none of the stepper coils should be under power.

As mentioned in my original post, I think that Linux is randomly setting some of the pins on the parallel port such that it's telling the driver board to power the stepper(s). If I fire up WIndows 8.1 on the same computer then power the driver board, none of the steppers are powered. Now if LinuxCNC worked under some version of Windows life would be great.

I don't have a breakout box for the parallel port so I'm stuck unless someone knows how check and set the pins on the parallel port through LinuxCNC or someother program.

Again, thanks for all comments!

richard5008 wrote:

Thanks for all the comments till now. The problem I'm trying to resolve is to NOT have the steppers under power unless they are commanded to be under power. When I first turn on the power supply to the driver board (TB6560AHQ) some steppers are randomly powered on by the driver board, sometimes it's the x axis, sometimes the y-axis, and sometimes both the x and y axes. The z-axis has never been powered on randomly, yet. This happens when LinuxCNC has not been started yet.

Until a device has claimed the parallel port and set its pins to meaningful values, it is in an unknown state

Your machine should not be powered until Linuxcnc starts and EStop and Machine - On are pressed
That is also what charge pumps etc are for

You need to change your wiring so that the drives are not enabled until under control

Logically (to me) they should be set to an idle state (none of the stepper coils powered) untill LinuxCNC or some other software control program tells them to do something. After that "something" is finished they should be set to an idle state meaning none of the stepper coils should be under power.

Wrong, if that happened your axes could move and you would lose your position.
More sophisticated drivers do power down to reduced amperage after a period of no movement, but the holding torque of the motors is required to keep the axes true

If I fire up WIndows 8.1 on the same computer then power the driver board, none of the steppers are powered.

Yes but then you have windows hate

I don't have a breakout box for the parallel port

Then you are just asking for trouble, buy a decent BOB with charge pump protection and buffered inputs.
All your motor movements will go away and you won't be able to short out your parport as easily

If your motors continue to run too hot, try reducing the amperage to the next setting down, but as people have said, they can get hot when working

regards

Until a device has claimed the parallel port and set its pins to meaningful values, it is in an unknown state

Your machine should not be powered until Linuxcnc starts and EStop and Machine - On are pressed
That is also what charge pumps etc are for

OK, this is a piece of information that I missed reading through all the documentation. I followed your power-up instructions and when I turned on power to the stepper driver all 3 axes locked up, even the z-azis which till now had remained free to turn by hand. From what you stated, this is to be expected and will keep stepper alignment to a reference point and not drift because I bumped something or in the case of the z-axis, gravity causing a shift. Now I get it!

A breakout box as you described is not in my future. This is a DIY project on the cheap.

Thanks for the comments.