On 3/13/23 12:51, Leonardo Marsaglia wrote:
[...]
Well, I tested it for almost an hour with no load at 15000 RPM and
the temperature settled at 55ºC in the bottom side where the bearings
for the tool holder are, and almost 65º in the body part where the
stator is.
According to one of the Chinese suppliers of these spindles, 75ºC
it's a pretty common working temperature. I'm still waiting for a
detailed answer from the factory. This time, the VFD worked fine, no
whining with no rotor spin. Now I need to cut some wood while
monitoring the temperature during the process and hope the temperature
doesn't go too high.
Anyway, I'm looking for new VFD drives just in case. From what I can
tell the problem could be the VFD as Gene and Jon pointed out.
One other point. The big supply caps in the vfd, according to some docs
I've read, can develop excessive ESR, and recommended replacement time
is 5 years.
If you had it running hard for those 5 years, that is another possible
problem. That, given the cap makers are learning, might be a one time
thing. That will give itself away if you can see the cap terminals with
an IR thermometer. They will be HOT. You say its hit 45C, so I'd suspect
anything over 50C. I have not had to do that, yet...
Capacitors are the highest failure rate of any electronics parts
assembly by a large margin. That and fuses that look good, until
inspected with a microscope. The fusible element will be found to be
crystalized, and eventually breaks due to bending fatigue, but isn't
blown in the classic sense. Looks great, till you check it with an
ohm-meter.
Cheers, Gene Heskett.
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/>
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