- devon, uk
According to that manual, the main motor is 3 hp. I couldn’t find a hp rating for the feed motor, but it’s probably less, maybe just a 1 hp.
If it was me I’d use an inverter for the main motor (but you might have to take it apart to dig out the star point so it can be wired in delta). For the feed motor, I’d ignore the higher speed (I’ve never used the high feed speed on any thicknesses I’ve used), and try it with a Steinmetz connection - wire L and N to 2 of the three phase terminals, and add a run capacitor between L and the third phase connection. You may have to play around with capacitor sizes to roughly balance the voltage between the phases. My 1 hp hacksaw motor has been running like this for years quite happily.
@doubleboost wired a pillar drill up with a Steinmetz connection a couple of years ago istr he did a video of it.
Edited to add: - I have a HuanYang 2.2kW vfd from eBay on my Harrison lathe - about £90 five years ago and has run perfectly. The hacksaw motor was much cheaper - £6 for a 35uF run capacitor!
I was thinking about this further -
The main motor, assuming the terminals can be bought to the surface, should be able to be handled by a vfd.
The secondary motor - is this impossible to run off a vfd, even if a cap is the cheaper option?
The reason I'm asking - the vfd are cheaper than I thought they were and im wondering if just throwing a (relatively small) amount of cash at it for a second vfd might not be simpler?