Wiring cooling fans for steppers

[sam-skovgaard 0]

I have noticed that the stepper motors run kind of hot, and I had a really big print skip a step on the x stepper about 5 hours in, angering me profusely. I want to add some additional cooling to my stepper motors to prevent this sort of thing from happening in the future, and I imagine that it would probably be good for the longevity of my steppers.

I was thinking that I could just wire three little fans like these: http://www.directron.com/ec3007m12ca.html?gsear=1

in parallel with the fan that cools the electronics, that way they will always be on if the machine is powered up. For me, the arduino is a magical black box that I have almost no understanding of; is there any problem with this approach? Will there be enough excess current to power these fans, or will I end up destroying my magical black box? Is there a better (but also relatively simple) way to go about this?

 

[joergen 2]

simply dial down the current used on the stepper drivers by a tiny bit: http://wiki.ultimaker.com/Electronics_build_guide#Tuning_the_stepper_motor_drivers

there is no need to run them any hotter than 60C, mine work fine at 45-50C, and there is no need for active cooling either.

 

[msurunner 2]

Check in with Snowygrouch, as he has cooling EVERYWHERE!

 

[snowygrouch 1]

You dont NEED to cool the steppers. They will work perfectly well without fans on.....however I always operate on

simple principles for all electronics (which is because Im a mechanical engineer..not an electrical engineer)..which is that for 99% of electronic components if you were to draw a graph of Temperature vs Component happiness....as temperature rises the happiness of your chip/motor/board/resistor/capacitor/battery goes down. When your components are eventually so hot as to be miserable they often decide to bail out and die.

So...I play safe and opt to keep all the components at maximum happiness... :mrgreen:

There may be exceptions where this is not REALLY needed. But its a rule that works for me...so I stick to it.

These steppers are probably not exactly industrial automation grade....so if I get 4 years out of them instead of 3.6. I will be very happy with the extra effort.

C.

 

[sam-skovgaard 0]

Thanks snowygrouch, I have a similar philosophy on component happiness. So would wiring the fans in parallel with the big cooling fan that cools the electronics be the best way to wire it?

 

[snowygrouch 1]

I run all my cooling for steppers and hotend from an external PSU. Which is annoying because

it means an extra cable - however I like having independant control over the fans.

If you want to wire it into the standard electronics, you need to ask someone who knows about that (not me !).

C.

 

[kristen 0]

Looking at the components in Eagle, the drivers For the hotnend and board fans should definitely handle a few more fans in parallel, but I'm not 100% sure about the traces or how that might affect the board temps. I'm planning to run my stepper fans and some led lighting off my second power supply for the heated bed.

It definitely aucka to miss a step on a big print. I've only had it once, it at 8hrs in it is super frustrating.

 

[joergen 2]

I find active cooling of the stepper motors unnecessary. i think it's easy to dial in the correct stepper current, and let them run warm, but not boiling hot, without missing a single step.

if you are still missing steps, you have mechanical problems: too much belt tension, miss-aligned axis, not enough proper lubrication.