Hot Steppers

[Xnaron]

I've got 4 gecko 203V's driving 4 hobby cnc 425 oz/in steppers. I am using a 56V DC power supply. The steppers get quite warm with the controller on and the steppers not moving. I just ran a program that cut for about 30 minutes and the steppers were hot. I couldn't hold my hand on them for more than 2 seconds. Is this normal? Is there something I can tweak in mach 3 to allow the geckos to drive them cooler?

thanks,
Brendin

[Crevice Reamer]

If you are running those motors Bipolar Parallel, then they should only be drawing 4.2A. What size current limit resistors are you using?

CR.

[Xnaron]

Originally Posted by Crevice Reamer If you are running those motors Bipolar Parallel, then they are drawing 4.2A. What size current limit resistors are you using? CR.

I am running them in bipolar parallel and the current set resistor is limiting it to 4.2A.

Brendin

[Crevice Reamer]

So what size resistor did you use?

CR.

[Xnaron]

Originally Posted by Crevice Reamer So what size resistor did you use? CR.

I believe the value was between 63 and 68K.

from the manual

Here are the current set resistor values for motor current in .5A increments. Round the appropriate answer to the
nearest 5% resistor value.
a. 1A – 7.8K
b. 1.5A – 12.8K
c. 2A – 18.8K
d. 2.5A – 26.1K
e. 3A – 35.25K
f. 3.5A – 47K
g. 4A – 62.67K
h. 4.5A – 84.6K
i. 5A – 117.5K
j. 5.5A – 172.33K
k. 6A – 282K
l. 6.5A – 611K
m. 7A – OPEN

[Crevice Reamer]

Are you absolutely sure that you have wired the motors Bipolar Parallel and not Bipolar Series? What is the measured output Voltage of your PSU?

CR.

[phungi]

Does your motor/mount setup allow for any kind of heat dissapation?

[Xnaron]

Originally Posted by Crevice Reamer Are you absolutely sure that you have wired the motors Bipolar Parallel and not Bipolar Series? What is the measured output Voltage of your PSU? CR.

Yes...54V measured. I got some responses on another board and these motors run HOT and max temp is 200F.

[Xnaron]

Originally Posted by phungi Does your motor/mount setup allow for any kind of heat dissapation?

No...I am going to cut some aluminum mounts for them as apparently that helps and they will only run warm.

[Xnaron]

I measured the temp and it was 143F. I was told that the max temp for these is 200F and that I could run them at a lower voltage to reduce the heat and I wouldn't lose that much power.

I'll probably make some aluminum mounts to replace the HDPE or perhaps put som heat sinks on them. I am not too worried though as they were well below the max temp.