IC overheated

After much work has been done to obtain all the parts I need, I have finally assembled the electronics 2.0. The Helix 1.0 has two problems to overcome before printing, however. The first is that when I turn on the electronics, the stepper controller's bigger IC heats allmost immediatly. After 30 seconds, it is almost scorching. Is this normal? If not, I tied my heatsink on with some solder (just the wire!), that may be causing this. I do not know. The second problem I will post after I resolve this issue.

It is normal for a stepper control chip to get hot. I've been burned by a few in my time. But you should use a large heat sink on the control chip and use some thermal grease between the chip and heat sink.

The chips will also overheat if the motor is drawing too much amperage. Make sure that your controller chip is rated for your motor.

And of course, there is always the possibility that you have a short somewhere or that you just got a bad controller chip.

---

Sleep is the evil brother of Death

Thank you for your help.

Got the same observation (hot steppers and stepper controller chips with Arduino electronics, stepper driver v. 1.1).

It seems to depend on what position the stepper is in - two of the steppers & their controllers got scorching hot, while one was relatively cool - I swapped around the steppers, and determined that it was the stepper that caused the temperature differences. I then turned the stepper motor axis of the cool stepper a bit when the power was off, and after that it heated up to hot temperatures.

I didn't repeat it, so not that reliable observation, but maybe a theory could be that different amounts of current can flow through depending on the exact positioning of the coils?

Anyway, I'll probably shop some heavier heat sinks for the stepper controllers, I don't want them to start melting the plastic of random wires that happen to touch them... :-P

-- zzorn

Edited 1 time(s). Last edit at 06/16/2008 06:33PM by zzorn.

... with half- or microstepping the count of enrgitized coils and the current per active coil vary in respect to the actual position.

The motors have different currents, torques and thus heating when staying energetized in a "fullstep-position" or between.

You can avoid excessive heating with reducing current in pause-mode - this is common in comercial stepperdrivers and is normally made by enabling this built-in function in microstepping-IC's ...

Viktor

Zzorn, the Arduino stepper driver boards I'm using have a pot to adjust the current; I think the idea is to turn it down to the minimum amount of current you need to run your steppers. My x axis only needed 0.3 A to run very nicely, but the other axis will need more current. At 0.3 A nothing really heats up, but at 1.5 A things do start to warm up.

Also, if you've got one motor that's always getting hot, check the coil resistance with your multimeter - maybe it was wired wrong, or perhaps it developed an internal short. I know I accidentally wired one of my steppers wrong, even though I thought I checked it.

Hope that helps!

Wade