The Meddings pillar drill which I have been working on is fitted with a
1/2hp Newman 3phase dual voltage motor. After some dismantling and cleaning it is now wired for 3 phase delta operation rather than star.However, I'm not sure of the best way to run it from a single phase supply. My memory of three phase theory suggests that a rotary phase converter is basically a 3 phase motor run on 2 legs with some auxilliary starting arangement (e.g. a single phase motor coupled to the shaft). Therefore I suppose one option is to obtain a large surplus 3 phase motor and use it in this way (but at the moment my only 3 phase motor is the one I am trying to run!) and the necessary collection of contactors for the starting arrangement are likely to be somewhat pricey.
Another possibility would be to buy a digital inverter drives, but there seem to be a lot of manufacturers and variables and the provision of additional speed control doesn't really seem that useful on a 5 speed pillar drill (although it would be very nice on my lathe!).
The simplest solution would be to replace the motor by a suitable single phase one of suitable power (e.g. 3/4hp).
Judging by other posts in the newsgroup it seems that the inverter drive method is quite common. Is there been a good introductory article on this approach? Google seems to throw up a lot of manufacturer's publicity, which while useful isn't exactly objective.
Alan