Z motor very hot

Is there anything that would cause the Z motor to get very hot? It is doing a fraction of the work of the X and Y but it gets very very hot. I cant figure out why. Everything is from you Vicious1 nothing changed on my end.

Has it always been “hot”. Can you give an estimate of what “hot” is. Theyvare rated to i think 50c over ambient. But since we use pla best to keep them under 60c.

My z gets warmer too for sure. My xy barely get warm, if at all. I think this is because of that thing about how steppers work, the way they deliver power in their phases. And apparently a moving stepper actually stays cooler. It also might have to do with only 1 stepper on z, which the xy have 2 set up so the current is limited. Or does the ramps send out twice the current for xy? Not sure

Hot to the point I can’t hold my hand on it tight for more than 3-5 seconds. Like very hot. I have a laser thermometer somewhere and will try to get an actual measurement. It’s just wierd and counterintuitive. I’m glad I’m not the only one though.

Not the motor that runs the extruder. The one that pulls the gantry up and down.

What is the voltage of your z axis stepper driver?

How would I know that? As in how do I test and get that number for you? It all came straight from you so I never had to learn how to do any of that.

Unplug all power sources and try swapping the y and z drivers see if that helps.

To check you need a multimeter.

OK I swapped them. If anything its hotter. I have a multimeter where do you want me to test?

From the power plug ground to the small silver pot on the drivers. 0.7V is what is should be close to.

Are you sure it is hot enough to burn your hand? Normally the driver will shut down from thermal overload long before that point.

Its hot enough that I cant hold it tight for more than 3-5 seconds before I am forced to let it go. Trying to find the laser thermometer to get you an actual reading. The heat sink on that particular stepper gets way hotter than the other 3 also.

If it helps at all, my xy steppers get to about 85f, and my z gets to 115f, running the stock vref. Check for binding in your z, and I found that putting some white lithium grease on the all thread made it a lot smoother.

Yep it reads .7

there doesn’t seem to be any resistance in the movement and I have Lithium on it. Shouldn’t matter either way as there is very little movement while printing. its .2 mm per layer at 28 mm/s so shouldn’t be taxed at all.

Found my infrared thermometer. Z is at 128 degrees. X is 99 and Y is 100. Does that seem right?

Fahrenheit btw

I really am not sure, since works and the setting are correct. Physically swap the steppers, and see if the problem follows.

Even though it isn’t moving the stepper stays powered up to hold it’s position.

That is much hotter than mine but well within specs, they are rated for I believe 50C over ambient.

You can turn the driver down as well that will cool it down. go down in .1 volt steps or less.

OK. I mean if its ok then its ok. Just seemed really extreme. I did the swap with the Y and it stayed the same. So not in the stepper. Guess thats just where it sits at. Thanks. Just had me worried.

Just turn down the pot on the driver. If you have a meter it only takes a second. Now that we have squashed the software bug we should not be having z axis issues anymore anyway.

I’m not. After much much much learning and tuning i am getting great quality prints. The heat just concerned me as it was so much hotter that the X and Y which do way more work. Does turning it down to say .6 or so change any settings or values?

No not at all. Turning it down should do nothing but cool it off a bit. too far and you will start to lose power but .5v or so I doubt would be a noticeable loss in power. Better than warping a mount from the heat.