Hot/slowing down steppers

Hi all, as I was doing a wood carving that was supposed to last an hour and 40 minutes the steppers began to get hot. I came back out to check on it later and they were really hot and my LCD showed that the project was only like 1/5 done, and that was after 2 hours of carving. My machine seemed to be going in slow motion. My Rambo board was also a little hot. I bought my kit from the website with series wiring. Some have suggested to lower the power to the steppers, but I don’t have the slightest idea of how to do that. Thanks

How hot, could you keep your hand on them? If you bought all of my hardware there should be no issue. If you changed anything than yes you need to set them appropriately.

The only thing that could make every single stepper too hot is over tightening everything or running with inappropriate settings.

I didn't adjust any of the firmware. But it is being kept in a warm garage if that effects anything. I left the machine on without the steppers moving and they still heat up a bunch.

That is hard to quantify. Yes they do get warm/hot. If they melt the PLA mounts…too hot, I can keep my hand on mine no problem.

@vicious1 tonight with my first successful test, I’m sure I was baby stepping the 1/8 endmill with multiple cuts but I did notice the steppers were all hot. Not like melting or anything but they were working but we had about solid 2 hours of milling. I’d assume we wanna push the tools a little bit but I didn’t wanna over due it. However now I’m concerned with burning up the stepper motors? Is there a solution or a temp they should be at ? I do have a infrared gun I could check and see. If we have a range they should be within.
Also within tonight’s run, did notice there is a pause function, guessing that wouldn’t help them cool down as they will be enabled the whole time?
Open to suggestions just wanna make sure I’m treating this unit right. As I’ve just gotten a handle on things and hate for something to go out

Try not to reopen these old posts (this one is 3 years old). Things change too fast to be adding to anything more than maybe 9 months old.

The motors start almost the same temperature if they are moving or staying still. The rule of thumb is about 50C. If they get too high above that, the plastic can bend. The main control we have for temperature is the current setting. If your motors are too hot, you need to reduce the current.

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Thanks @jeffeb3 Ill work on getting better at looking over the post date that way I don’t comment on the older stuff. I get so hung up on using search functions. Few other forums for other things I’m in, guys go wild over not using it.
Luckily you guys are not like that one! My apologies man. As for the temp, I will have to check mine and see eBay they were at. I mean they felt hot but like said, I think I was over conservative with depth of cuts which lengthen the machining time a ton.
Jumping the gun here, how would one reduce the current on the stepper motor it self? Longevity of those go for awhile? I thought about ordering a few to have them on hand.

Stepper motors are rock solid. They almost never fail. The drivers will fail first.

The current adjustment isn’t on the motors, it is on the drivers. TMC drivers and rambo boards are controlled with the marlin firmware. There is probably a setting in the menu to adjust it. Something around 900mA is a good starting place. If they are too hot, drop them by 50mA or so. If you go too low, you will skip steps.


The steppers will feel hot, if you got the steppers and control board from me they are set right. If you sourced it yourself you need to verify your temps.

The way they work is pretty crazy, once they are energized, can’t move them by hand, they heat up high load or no load.


Thanks @jeffeb3 and @vicious1
I’m gonna assume he got them from you directly . The guy I purchased the lowrider from. For the setting I’ll see if I can find it in the controller see what it’s set to.
I won’t worry too much as I figured they are designed to do what they need to do. Plus I wasn’t 100 on my tooling speeds so prolly ran much longer than it needed too. However from
This thread below

Time running isn’t really an issue, may source some ideas about the heat sink. Just not sure a good place for em on the lowrider