prevent motion

[cosmund]

We are using the MID-7604 Power Drive to the motor system.

[AnalogKid2DigitalMan]

Can you attach a sketch of how you wired the motor to the drive.

Have you referred to the manual, have you set the DIP switches for peak current accordingly (pgs 13-15)?

Have you tried setting DIP switch 5 off to disable current reduction?

http://www.ni.com/pdf/manuals/372454e.pdf

-AK2DM

[cosmund]

Yes, the DIP switches have been set to current reduction mode. How does that impact holding torque?

Anyways, there seems to be some holding torque now! It seems enough for our purposes at the moment. I'm not sure what changed recently to cause it to work now, but no complaints.

[AnalogKid2DigitalMan]

The manual states:

You can configure the MID-7604/7602 stepper drivers in a current

reduction mode on a per-axis basis. This configuration is useful to

minimize motor heating when you are not stepping. With current reduction

 enabled, the current decreases by 50% when no stepping has occurred for

approximately 500 ms. DIP switch 5 controls current reduction on a

per-axis basis. When this DIP switch is on, current reduction is enabled.

When this DIP switch is off, current reduction is disabled. The factory

default setting is current reduction enabled.

[CWolf]

Cosmund,

Having current reduction mode enabled on the drive will reduce the holding torque.  This is because the current drawn by the motor is what causes it to stay at its present position.  (This is how you can tell if a stepper motor is properly powered; it is be a lot easier to turn when it is not powered.)  So, if the amount of holding torque that you are seeing right now is not enough, you should change the dip switch setting to disable current reduction. 

-Christina

[cosmund]

Christina,

Thanks for specifying the relationship between current reduction and holding torque. It was not very clear from the manual.

cosmund