Crazy Idea - converting Air Cooled spindle to Water Cooled

[BanduraMaker]

I realize that this is a completely nutty idea but I thought I'd throw it out there anyway.

I have a 2kW air cooled Teknomotor spindle and it's much louder than I expected. It turns out that all the noise is from the impeller mounted at the top of the spindle. This is borne out by the fact that covering the inlet with your hand eliminates about 90% of the noise from the machine.

The air cooling is accomplished through 4 through ports running from the top of the spindle and exhausting out the bottom. I think that by making plastic plugs for the 4 ports with an inlet/outlet for a tube, I could probably convert the spindle to water cooling and, it would be reversible. As a side benefit, I'm sure the thing would run a lot cooler too.

The most difficult part would be removing the impeller I imagine.

Am I totally off my rocker or is this something that sounds kind of feasible?

[JerryBurks]

I don't know that spindle but if it is not designed for it I doubt you can seal it properly. Electricity and water don't go well together.

Funny enough, I am going to air-cool my water cooled spindle
But I am going going to use the dust extractor air stream to do that.

[BanduraMaker]

I think it's already sealed - the spindle body is a rectangular extrusion with a cylindrical inner portion for the electrics and 4 channels for the air. I think it would be rather easy to seal up the top and bottom. There are a couple of screw holes going in there as well which would also be cake to seal.

You did give me another cockamamy idea which would be to use my dust collection to cool the spindle and the ports in the bottom to actually suck up the chips! - I think that the holes are probably too small but the idea is kind of neat.

[ger21]

Our 15HP SPindle at work is cooled by the dust collection. It's a 12" round duct, that incorporates the spindle clamp centered inside. Trying to suck dust through those small opening would probably lead to clogging.

Imo, I'd deal with the fan noise. Is it really louder than the combination of cutting noise and your vac or dust collector?

[JerryBurks]

I think it's already sealed - the spindle body is a rectangular extrusion with a cylindrical inner portion for the electrics and 4 channels for the air. .......

Hm, don't know maybe possible. The easiest way might be to route some copper tubing through the channels and pot them in place with heat conducting epoxy. That is, if you really want to risk ruining a perfectly good spindle....and if you are at it you could just grind off the impeller vanes if you can not take it off easily. Or you could sell it and buy a cheap Chinese water cooled spindle.

For my dust extractor cooling I am just planning to do what Ger21 wrote. There will be a shroud for the dust extractor around the cylindrical spindle body and I am quite confident that the high air velocity and volume should keep the spindle cool. Additionally the spindle is mounted on a massive aluminum plate that should also contribute to cooling. After all it is only 1.5kW.

[RomanLini]

There is someone on the forum (maybe in NewZealand? I can't remember) but he took the fan off the shaft, and used an external quiet square fan (like one of the new PC fans) to blow air down through the router.

You could do the same to the spindle, provided it is not pushed to the limit where it needs big cooling.

[BanduraMaker]

Yes, that's also a definite possibility. Teknomotor even makes one like that straight from the factory but I didn't know about it at the time I purchased this.

That would probably be a heck of a lot easier than making plugs and plumbing etc and also has the advantage of a constant airflow even when running the spindle at low speeds.

A buddy has one of those infra red thermometers that I'll have to borrow to see how hot it runs. I actually bought a large heat sink that I cut in half to mount to the sides to help keep things cool too - between that and a cooling fan I might just be in business.

Dum question - To make life simple, I'll probably just have the fan running when the VFD is plugged in. There's no risk in pulling a 120v line from one leg of the 220 going to the VFD is there? I mean, the legs are already randomly balanced anyway right?

[JerryBurks]

FWIW, the IR thermometer will not read correctly when aiming at a bare metal surface (should be painted or plastic).

If you want to see the temperature real time without fuss you can buy a pack of stick-on thermometer film strips (e.g. McMaster # 59485K26).

They are cheap so I put one each on the spindle, all steppers and the drive heat sinks.

[zool]

There is someone on the forum (maybe in NewZealand? I can't remember) but he took the fan off the shaft, and used an external quiet square fan (like one of the new PC fans) to blow air down through the router.

You could do the same to the spindle, provided it is not pushed to the limit where it needs big cooling.

Roman I think this is what you are talking about:

http://www.youtube.com/watch?v=OHd9dAIs85I&feature=mfu_in_order&list=UL]Experiment in spindle cooling Twin Turbo Router - YouTube

[BanduraMaker]

FWIW, the IR thermometer will not read correctly when aiming at a bare metal surface (should be painted or plastic).

If you want to see the temperature real time without fuss you can buy a pack of stick-on thermometer film strips (e.g. McMaster # 59485K26).

They are cheap so I put one each on the spindle, all steppers and the drive heat sinks.

Good idea on the stick on thermometers. I need to order some stuff from McMaster anyway.

Another idea I had on cooling is to simply make a Y joint on the dust collector. I've got a Kent dust skirt but hopefully there would be enough airflow to suck chips and air through the spindle.

[RomanLini]

FWIW, the IR thermometer will not read correctly when aiming at a bare metal surface (should be painted or plastic).

If you want to see the temperature real time without fuss you can buy a pack of stick-on thermometer film strips (e.g. McMaster # 59485K26).

They are cheap so I put one each on the spindle, all steppers and the drive heat sinks.

That's a very cool idea (pun intended). I'll have to look out for those stick on thermometer strips. As another solution to getting the infrared thermometer to read the temperature of metal, one trick I have used on the workbench for years to read the temperature of heatsinks etc is just to stick a white paper sticker (printer label etc) on the metal, then read the temperature of that.

Zool- Thanks yep I think that's the guy. Pretty clever setup.

[Phy6]

Bringing this post back from the dead. I came across this looking for a water cooled version of the square spindles, with the thought of converting one to water cooled as well. After looking at the open end of the extrusions, one solution would be to run some flexible copper tubing (as big as you can fit) through the extrusion holes, and then run water through that. You'd want the copper to have maximum contact with the aluminum to transfer heat. (Not sure if you'd get enough galvanic corrosion to be concerned with, but definitely more secure than several o rings.)