3040 CNC Engraver / Mill Motor Heatsinks

Last year I got a 3040 CNC machine. It's worked pretty well over the past year. The only thing that bothered me was that the motors got pretty warm on very long jobs....

You only need three things. Heat sinks, Thermal Grease and Dryer Hose Clamps

I looked around and found some pretty cheap ($1.25) square heat sinks that were just a little larger than the motors themselves. I had the thermal grease and with a quick trip to Lowe's for some clamps it's time to start assembling....

Step 1: Z Axis First

I figured I'd start with the Z axis since it was going to need some special relief cuts on one of the panels to clear the spindle when it come up. I could have just nipped off the lower half of the fins but why not use a mill to make it easier. If you don't have a mill that can cut aluminum a Dremel will work just fine....

I used a 1/2 inch end mill and carved a simple pocket by hand and checked it for fit before painting everything flat black again. The wire slot was simple too just a notch to clear the wires on the motor.

Step 2: Dry Fit

I put everything together with some clamps to see how it was going to fit. When I had everything in the right place I bent the Lowe's hose clamps to a matching square shape...

Step 3: Disassemble and Add Thermal Grease

I disassembled the heat-sinks and added some thermal grease to the back side. I couldn't find a squeegee so, yes, I used a saw blade...

After reassembling them I pulled one panel to see if there was good contact with the motor. It looked pretty good so everything went back together and I did the same for the other two motors.

Step 4: All Motors Done

All the motors are done. I never had the spindle even get warm so nothing was needed there.

Step 5: Temperature Display

I looked in my PC spare parts bin and found some CPU temperature meters. They run on 5V so i tapped off the supply in the controller box. Most of the ones I have allow you to switch between Fahrenheit and Centigrade using a switch on the back. A couple of them did not have this switch but I opened the case and, sure enough, there were the pads on the board. A little solder blob jumper and they all read in Fahrenheit now.

Since these were PC heat sinks the sensor clipped right in without any effort. You could slide it under the clamp but I tried to pry one out and its in there pretty well.....

I have to mill a nice front panel for these. I may add a 4th for the spindle just for the heck of it....