Water-cooled Nomad Pro

[bajcz (Max Bajcz)]

I’ve been meaning to share this for a while and just now getting around to it. I had always been a little alarmed by how hot the spindle and spindle motor got on longer jobs. I didn’t think that adding heat sinks would do much given the limited air flow in the enclosure and a fan would likely just get caked up with dust constantly. About a year ago, it finally cooked one of the limit switches. Of course Carbide3D overnighted me a replacement at no charge because they’re the best. Still, I didn’t want to have that happen again, so I decided to go down a different rabbit hole.

I had a few goals when I started figuring this all out.

1. I wanted the whole thing self-contained. I didn’t want to have to worry about knocking over a container of coolant or tripping over hoses. I also didn’t want anything that was too tempting for my pets to chew on. I sometimes take my Nomad with me to things like Science Olympiad practices, so it needed to remain portable without having to drain and refill the coolant.
2. I wanted to avoid modifying the enclosure any more than I had to. Minor changes would be OK, but the aesthetic should remain intact.
3. I figured this would be a good opportunity to add a tool tray to the machine.
4. I sometimes run the machine with the back cover off for longer pieces of material, so I didn’t want to lose any vertical or horizontal clearance.

Long story short, I purchased some computer cooling components from Amazon and put the whole thing together for about $100. Here’s what it consists of:

2 cooling blocks (40mm x 40mm x 12mm). They’re “temporarily” attached with a heavy-duty ziptie with a spacer in the front to keep the blocks from drifting toward the rear. I started making something more permanent, but this has been working well, so…

A bunch of silicone tubing and zipties to route it along the top of the drag chain.

It’s routed through the existing opening for the x-axis stepper motor wires and down to the underside of the machine.

It then exits through another existing opening to go to the radiator, which has a fan attached. I made the housing out of some scrap pieces of Ikea bamboo cutting boards, so it matches the look of the rest of the machine pretty well.

In the back of the machine, I attached the reservoir and pump.

And, it topped it off with a tool tray.

That’s it, really. The whole thing is whisper quiet and the spindle and motor just barely get above room temperature when it’s running. Now for the list of things I would do different if I were starting over.

1. The reservoir is much bigger than it needs to be. I later found a 1-piece pump and reservoir that would have fit to the right of the controller case that would have been perfect.
2. I would have put the radiator on the left side instead of the right because the USB and power cords are kind of in the way of the tools.
3. I could have used a third, larger cooling block attached to the aluminum structure of the machine instead of a radiator. That would probably be plenty adequate to dissipate the heat.
4. I really wanted to have a tool tray on the machine. It’s really convenient, but all of the bits rattle while the machine is running and I could do without the extra noise.
5. Items 3 and 4 above would also eliminate the extra chunkiness of having something attached to the side of the machine.

[bajcz (Max Bajcz)]

I should add that I considered using Peltier cooling, but thought that it might result in some electrical interference. Probably worth some experimentation. It would certainly be an inexpensive method and no coolant needed.

https://www.amazon.com/dp/B00M1PM7H6/ref=sspa_dk_detail_0?psc=1p13NParams&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExM0xFMTc0NVVYSjFZJmVuY3J5cHRlZElkPUEwMTY0MjI3MVE3NTZJTDlUWUtLOSZlbmNyeXB0ZWRBZElkPUEwMzA1MzY1MkpUVU41REYwUDBHVSZ3aWRnZXROYW1lPXNwX2RldGFpbDImYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

[Gerry]

This is pretty cool (pun intended) !

I’m a bit concerned now about my nomad! I’ve run it, sometimes for for six hour jobs, over a couple of years now, and never checked how hot it might be.

How did your heat-related problems manifest? Did the machine stop working? Was there a deterioration in performance?

[bajcz (Max Bajcz)]

The amount of heat produced depends on what you’re doing and how hard you’re pushing the machine. I would guess that there is at least as much heat generated in the bit as there is in the motor when you’re doing something like dry machining aluminum. As the whole gantry is aluminum, that heat is transferred readily throughout. If I recall, when I cooked one of the limit switches, I was working some aluminum with a #102 bit. A single-flute endmill will generally produce less friction and bigger chips, which sheds more of the heat than a multi-flute endmill.

There was no deterioration in performance at the time until I had to do a bit change and got an error when it tried to move to the bitsetter. I was able to isolate the issue by checking the continuity on each of the limit switches. I was happy to confirm that was the issue and not that the sensors in one of the servo motors.

On an unrelated note, upgrading to a 78W spindle motor was a huge improvement. You lose about a centimeter of z-axis, but it’s a plug-and-play upgrade and you can suddenly start using 1/4" endmills - in wood and plastics at least.

[Gerry]

Understood. I only really cut aluminium and brass on the machine and it’s never been to hot to touch or even noticeably hot. Perhaps my machine is blessed.

I looked at the upgraded motor but so far as I can tell it’s the same tall model as the one that is already in the machine - perhaps some later models already had the upgrade?

[bajcz (Max Bajcz)]

I’m still a very novice machinist, so my feeds and speeds may have been a contributing factor to the heat buildup. With the bigger motor, I’m more comfortable pushing it a bit harder. Lower runtime = less heat generated.

It’s possible that the larger motor became standard. The one I bought is linked below. My machine came originally with a ~50W motor and would frequently stall if I wasn’t particularly conservative with plunge rates.

# 42BLF03