Talk to me about VFDs.

I have just grabed myself a bargin,:eheheh: in the form of an old cast iron lathe.....you can just feel the quality.....I'm realy going to feel the quality when I have to get it off the trailer:sweat:......its more or less complete, less motor.



So I've managed to ebay myself :tiptoe:a near new, 1.1Kw GMC 3 phase motor & i'm doing my homework on VFDs.



If I can lay my hands on a 2hp motor..I'll do so and I'll probably sling the GMC on my drill press.



I know this in the CNC part of the forum...but it seems to be the repository of VFD information.



So a couple of questions.:think:



Who are the reputable VFD suppliers on ebay these days.....I'm watching one of these http://ift.tt/1DkwUhn.



I know the VFDs will vary from about 0Kz to 400Kz, but what is the reasonable limtation.



I gather there are cooling issues at the low speeds and no doubt there will be balancing and spinning distruction issues at the higher speeds.



Are there limitations caused by the induction in the motors in particular the larger ones.



I gather there are now motors, like these spindle motors that are specifically designed to be run by VFDs......what is the effect and limitations on stock 3 phase motors not specifically designed for use with VFDs.





cheers