Stepper Motor Phase Current with TB6600

Hardware
1

Hello,

I am not sure if this is the right Forum for this problem, but I'll ask anyway:
I want to control a (geared) Nema 14 Stepper Motor with a rating of 1,5A per Phase with a TB6600 Stepper Driver. The code and everything works as expected except for the "low" torque the Stepper had. I was using the Current Setting for 1,5A on the Driver. Since I was expecting more torque from the motor I measured the current through one Phase and got 0,65A which is a little below half of the 1,5A I was expecting. (I measured this current while the motor wasn't moving). So now my question is did I configure the driver wrong? Does 1,5A on the Driver mean 1,5A total and i would need to use the 3A setting, or does it mean that the current can go up to 1,5A when moving but it goes below that when not moving?

I hope someone can tell me if I misunderstood something in regards to using this driver or stepper motors in general.

2

Try raising the voltage. The driver can go up to 42 volts, as seen on an advertisement. The torque depends on how quickly the maximum current can be sent to the motor windings.
Did you measure the required torque before you built the project?

3

I am currently using ~24V as supply, since my project is battery powered I also cannot exceed this voltage (I don't want to use a DCDC-Converter to raise the Voltage). Also no I didn't calculate how much torque I really need. I am using a motor I had laying around for a prototype. I definitely will calculate the torque I will need after playing around with the prototype and if necessary change the motor for a bigger one.
But its not really about the torque I need, but about why only ~1/2 of the current, I set on the driver is going to the motor. I didn't work with steppers much till now and don't know if this is the intended behaviour of the driver or if I can up the current setting from 1,5 to 3A which would probably lead to me measuring twice the current which would be around the rating of 1,5A.

4

The current is in pulses. Unless you measure with series resistor and an oscilloscope, you cannot know the actual current during the pulse.

5

Oh right, that was a measurement mistake, now it makes sense, thank you

6

The current is NOT in pulses when the motor is not moving. But the driver may reduce the current in this case ( But I don't know if the TB6600 does so ).
How did you select micro stepping?

7

Good point! The documentation will or should tell this. OR perhaps the program disabled the TB6600.

8

I looked into the datasheet. In the features section:

※ Automatic semi-flow to reduce heat

From that I assume in standstill it's only half of the set current

9

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