Second Stepper Motor Hot Not in Use

[iceman 0]

I recently installed my dual extrusion kit and everything went fine. I haven't actually tried it out yet because I haven't got my ultimaker calibrated really good yet so I have just been using one extruder for my test prints. However, everything for the second extruder is plugged into the electronics and while printing only with the first extruder the second extruder motor gets very hot (to the point you can't touch it long). All the other motors don't even seem a slight bit warm. Is something wrong? I am stumped on this one

Thanks,

Hunter

 

[anon4321 16]

Unlike other motors, steppers use current for holding torque when not moving so will also generate heat when not moving. You should be able to test this. Without filament in the second extruder, try turning the gear during a print then with the power off. During the print, you will probably feel a lot resistance because even though it isn't in use, the driver is enabled and the stepper is powered.

Steppers can take a lot of heat so you might want to just leave it alone.

If it really bothers you, you can dial back the current.

NOTE: Others including myself have damaged drivers while adjusting them !!!!!!!!!!

DO THIS AT YOUR OWN RISK.

See http://wiki.ultimaker.com/Electronics_build_guide

You don't need to use a multimeter, Just use the information above to determine how to reduce the current and then

just reduce in small increments WHEN THE POWER IS OFF.

Be careful and note that the drivers get HOT. Make sure you replace the fan/electronics cover after adjusting.

I would unload all filament and try to match the force required to get the second motor to skip against the first and then adjust a little HIGHER so you don't skip steps on the second extruder causing bad prints.

GOOD LUCK! HEED THE WARNINGS!

 

[iceman 0]

As long as its normal that's fine with me. Thanks!

 

[Dim3nsioneer 479]

IMHO it is not necessary that the unused feeder motor is active. I developed a switch-off-unused-feeder-motor-option for Marlin which works absolutely fine on my dual extruder Ultimaker Original. I'll see it finds its way into standard Marlin.

 

[drayson 74]

 

@Dim3nsioneer: Have you already opened a pull request for this?

[Dim3nsioneer 479]

@Dim3nsioneer: Have you already opened a pull request for this?

 

Nope, not yet. Maybe I'll do this tomorrow. I first have to get the most present Marlin version and incorporate my changes...

 

[Dim3nsioneer 479]

Ok, it's merged to ErikZalm/Marlin...

 

[drayson 74]

:-) great news!!

Just a question: it disables the stepper if not used - more detailed, not heated at the beginning. So no disabling when switching nozzles - correct?

[Dim3nsioneer 479]

It's not just that simple...

Every time the extruder is changed, it enables the motor of the new extruder and disables the motor of the old extruder. You never have the inactive stepper motor enabled again.

But it's only the stepper! There is no change for the heating of the hotend.

 

[drayson 74]

Ok - so worst case (if you dont know what you do) it is possible to move the filament by hand as there is no counter-force from the stepper.

Ok, nevertheless very sensefull feature - thank you for implementation!!

B.t.w. Do you have news about the "pause" discussion we had a while ago?

[Dim3nsioneer 479]

B.t.w. Do you have news about the "pause" discussion we had a while ago?

 

not yet...