Hot stepper motors, how much is normal?

[handyman 0]

I notice on my Ultimaker 2 that during printing, the stepper motors for x and y axis get really hot, to the point you cant keep your finger there for more than 10 seconds without burning.

Is that normal?

Is there any mod to cool them with fans?

Thank you for your help!

Alfonso

 

[ian 32]

they can get toasty warm thats true. After maybe 20 minutes printing. they can get pritty hot.

You can of course go down to the electronics board and with a small screw driver turn the POTS to the left a tiny bit and that will reduce the power going to the motors.. ie cooler...

But id be a little slow doing that. Normally the POTS are set to a default by ultimaker for best overall performance..

But if you feel secure enough.. have a look and turn the POTS back a little.. just be careful with your electronics board !

Ian :smile:

 

[woofy 12]

@Ian, Does the UM2 have pots, I thought it was controlled directly from the CPU (using a filtered pwm).

@Handyman, In my opinion, if you can put your finger on the motor for up to 10 seconds then you have no problems.

 

[ian 32]

i think your right ! my bad.

actually since iv been testing and printing with my UM2... i never had to touch the electronics.. always just thought the old POTS were still there..

Ian

 

[IRobertI 520]

Yup, no actual pots on the UM2.

I've read on the internets (which is always right, right?) that you can go up to about 80C for most steppers before causing damage. If you're able to hold your finger on them for 10 seconds without screaming they're no where near that.

 

[ian 32]

does anyone have a picture of where exactly on the board can I manually change the current to the motors if I wanted to ?

or how does that work exactly ?

Ian :-)

 

[IRobertI 520]

It's all done in firmware now. So you can either hack the code directly or use Gcode. For example M907 E1500 to set the extruder current to 1500mA.

 

[gr5 2,176]

M907 X1300 Y1300 Z1300 E1250

should set them all to default currents. Values are in milliamps and 2000 is the max although I'm suspicious of some kind of bug as someone reported that the extruder gets more powerful up to around 1500 and then starts to get weaker again as you go above 1500 - I think this might be a hardware bug with the stepper drivers. I'm really not sure.

Also B is for the second extruder M907 B1250

I played with this and reported results here (see posts #1 for the photo and #19 for the current testing):

http://umforum.ultimaker.com/index.php?/topic/4222-pulling-force-of-um-extruder/?p=35887

 

[handyman 0]

Thank you very much everybody for the help!!