Dealing with too much heat

How do we deal with the motors getting to hot?
Has anyone designed a fan mount to cool the motors at all?

Just for information purposes. It has been extremely hot here in Australia (35 degrees Celsius maybe more). Inside the shed I’m guessing hotter.

Hopefully you guys can see in the photos how the plan parts are starting to warp. Z more so than Y

Ouch. Hopefully it was limited to those parts.

The stepper motor max current is set (in the default firmware) to keep the motors under about 50C at steady state. That assumes some ambient temperature and should leave some room before the PLA gets squishy at something like 65C.

Some solutions from easiest to hardest:

You can drop your motor current a bit. Even 50mA makes a big difference.

You could reprint those parts in PETG.

You could attach a fan. I haven’t seen one on the LR3 yet.

You could move to a more temperate climate :slight_smile:

I may be able to do 3 if those 4 options haha.
Looking at fan clips on printables at the moment.

I’ll also look into dropping the voltage.

If those two dont make alot of difference I’ll try reprinting in petg. (Only ever used pla)

Thanks for the quick reply mate

Those are not my steppers, they look much shorter, did you turn the current down in your firmware?

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Hi Ryan,
No not yet I’ll look into that first.
All parts I had to source from either Amazon Australia or AliExpress.

I’m planning on building 1 more lr3 possibly 2.

I’m in love with this thing.

I’ll try purchase from you for the others (minus the printed parts, nuts and bolts etc)

I’ll also add that this has been a massive learning curve.

I have no experience with CNC, no idea about electronics, soldering, wiring etc)

Never used and of the software. Never flashed anything.

So basically everything to this point I have done via your instructions and some forum searches.

So thankyou for making this all available!

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Very Dali!

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So I figured I can make these fan mounts work for the y motors. Now trying ato look for a solution for the z
Uploading: 16746206779161516868222318477742.jpg…

So after searching the forums i have come up with the config file need to be updated?

//#define DIGIPOT_MOTOR_CURRENT { 135,135,135,135,135 } // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)

is that the correct line? I have an skr 1.2

then reflash?

No, that’s for the rambo.

You can change it with M906:

If you like the new setting, save it with M500 or else a reboot will reset it.

Thanks again Jeff. Was still reading the forums to work it out. I’ll take another look in the morning. Still trying to learn on the fly. Ill go through the commands and see what its currently set at.

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so I set using command M906 X850 Y850 Z850 (when i checked it was set at 900)
Havn`t tested under load yet but run some air cuts and left sit at idle for about 30 minutes.
So far seems they not heating up (i can keep my hand on there now atleast)

Ill keep monitoring temps and let you know the outcome.

Thanlks again for the help so far!

I took a look at the motors themselves as well…Seems i purchased the wrong ones.

That does not seem right. If you are using a SKR it drops the heat at idle.

I would assume you are at 700 and that might still be hot. Run an air cut for 45 minutes to see where you are at. A drop of 50 is not going to be that drastic.

Hi Ryan. Yeah the heat is going down at idle. I actually thought the Z may continue to heat up while holding the gantry. Ill keep an eye on that too.

So the motors I have (42shdc3025-24b)
Specs here

Not sure how. Must have messed up when sourcing parts and then didn`t ever check. Just installed.

Ill order new ones over the next day or two. (the recommended ones)

Those will work just fine you just need to tune the power to them. Not a big deal.

ahh ok good to hear. Everything seems to run fine. Everything moves and cuts fine.
I thought maybe the ambient temp may have added to the heat build-up. However, It’s early morning now, and it’s quite cool inside the shed.

Any advise and how-to accomplish this would be awesome. I`m extremely new to all of this.

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so I ran an air cut for 45 mins. dropped current to 700 and motors still run hot. (maybe touch them for 3-5 seconds before it gets too hot to touch.

I have a roll of petg coming as well as heat sinks and fans. Just incase i can`t get the temps down

That is what I expected. Drop to 600, keep dropping until it stays around 50C. I did all this for our steppers, you are using different ones so you need to figure out what they need.

If you do not want to melt your parts, start at 300 and only increase it by 25 every 20 -30 minutes until you hit 50C.

Thanks Ryan. I`ll get started at 300 and post back results.