[DonFrambach]

Just bought my first water cooled spindle. 1.5 kW from UGRACNC. Also bought a small pump and two radiators (figuring that I'd use only one). Naturally all the tubing connectors are different. The connectors on the spindle itself appear to be "push to connect". The connectors to the water pump are barbed and measure about 5/16" and the connectors on the radiators are also barbed but measure about 1/4". The water pump came with two clamps to secure tubing to its connectors.

I see a real potential for a disaster if I make a tubing connection that fails. The spilled coolant won't be great but a burned up spindle will be even worse.

I would sure appreciate suggestions and photos of successfull tubing connections. I'm also confused about what would be the best coolant.

Thanks. Don

Here's some photos:

[Jim Dawson]

The critical dimension is the push-in fittings on the spindle. Are they 6mm or 8mm or 10mm or maybe 1/4, 5/6, or 3/8? The black push-ring normally indicates inch sizes, but no guarantee of that. The tubing must fit the push-in fitting correctly. Then depending on what tubing you are using, it will stretch or clamp down OK on the barbed fittings on the pump and radiator. If you need to stretch it a bit, hot water works well to soften it. Go buy some good hose clamps.

I would use RV water system antifreeze, it's non-toxic and has some anti-corrosion properties. Available just about anywhere: Auto parts, hardware stores, Walmart.

[DonFrambach]

Took more careful measurements and found that the push-in connectors are 5/16", the pump connector needs 3/8" ID tubing, and the radiator needs 5/16" ID tubing.

Bought the appropriate connectors, hose adapters, and PVC tubing from McMaster.
Attachment 346028

Put everything together (except the hose clamps) and ran the pump for about 12 hours with no leaks
Attachment 346030

Kind of concerned about what coolant to use so picked up this at my local Frys. It's designed for cool looking water cooled computer setups. Don't care about its color but hope it will protect the spindle and radiator from corrosion and prevent microorganism growth.
Sure would appreciate comments about this.
Attachment 346032