Cooling fan on top of spindle died

[Greybarn]

The Papst multifan on top of my spindle has died. Temporarily, is it okay to continue to run the spindle without the fan? Or is this a fast path to killing the spindle? Seems like the fan keeps the dust away from the bearings in the spindle and may do a little cooling too. I can probably get a new fan within a few days but I would like to continue cutting parts in the meantime. Any thoughts would be appreciated.
Thanks for the help.
Regards
Peter G. Smith

[dana_swift]

Running without the expected cooling is very likely to destroy the spindle from overheating. You may have discovered that already.

The spindle is probably a simple three phase motor and not much else. No motor is 100% efficient, and the in order to get several horsepower delivered to the cutting edge, one or so horsepower has to be dissipated as heat from the internal resistance of the coil windings.

Not having a fan will probably run the core temperature above the limits of some internal component in just a few minutes.

So.. short term.. use your dust collector and duct tape some hose around the spindle top and keep air going through it, that way you can keep the temp down.

Beyond that, probably the first thing to melt will be the solder. Perhaps the enamel coating on the magnet wire, just moments after that the motor shorts out and destroys the VFD.

If you have any airflow going, such as the dust collector, or whatever to provide air flow, I would feel pretty free to keep cutting. The spindle doen't know or care HOW the air flow is generated! But the fan is there for a reason..

Good luck!

Keep the air moving through there..

D

[Greybarn]

Thanks. I cut one sheet of plywood today as a test to see how warm it would get and it did not seem abnormally warm. The fan is only 48 cfm...of course this on an area of less than 1/10 of square foot so the velocity is pretty high.
I think it is okay for limited cutting, or at least cutting soft material.
I can get a new fan delivered by Tuesday so I will take it easy until I get that installed.
Regards
Peter

[myxpykalix]

you could buy one of those $5.00 clip on personal fans and mount it on top in the meantime. I'm sure it won't be a substitute but I think something is better then nothing:eek:

[bleeth]

Replacing spindle costs a heck of a lot more than a day or two of cutting loss.

[srwtlc]

Do something to cool it and get a new one coming. I've had to replace two so far (on my third one). They aren't too tough to take apart and put some light oil in them if that's all it needs.

Best price I've found and quick shipping is from here...

http://www.alancomputech.com/8314h.html

You'll have to cut the connector off and solder it to the terminals on the fan shroud.

[Greybarn]

Agreed about the cost of the spindle versus waiting for a new fan. Found two fans on eBay almost for the price of one... Probably going that route.
Thanks for the replies.
Regards
Peter

[Brady Watson]

Make sure you get the correct fan. Some are 208/230, 240 and others are 24v.

-B

[Greybarn]

Got it. Mine is 24vdc.
Thanks.
Regards
Peter