RK05 spindle pulleys - trade 50Hz vs 60Hz?

[Paul Koning]

> On Jul 25, 2018, at 9:50 AM, GerardCJAT via cctech <cctech at classiccmp.org> wrote:
> 
> Why don't you simply power it through an inverter that will output 60 Hz, eventually even "down to" 120 V , true sine wave, of course ??? They are not that expensive by now. 

I wouldn't worry about "true sine wave".  That seems more of a marketing thing anyway, and motors don't care.  Just feed them with a variable frequency motor drive and all should be well.

> And be carefull : motor designed for 60 Hz, running "under" 50 Hz, OR THE OPPOSITE, I do not recall  !!!, display a significant reduced life time.
> I have to check which is which, but I know this is a question of saturated magnetic field. Better check first.

That doesn't sound right.  If you run the frequency up high enough you might get into problems with magnetic materials not designed for it.  And much lower probably gives you reduced torque.  But 50 vs. 60 Hz is a trivial difference for a motor, I can't see any reasons for that to cause trouble.  I routinely run my lathe at half frequency if not less, and it doesn't complain.

	paul