It's been a few years since I've posted, but I have been lurking for
most of it. I am resuscitating a B&S 2A universal mill to which I will
mount a Bridgeport head. What I would like to do is use the 5HP mill motor
as the idler in a RPC for the Bridgeport head, while still using it to power
the table feeds and pump, and horizontal arbor when required. Yes, I could
use a separate idler motor, but don't see the point as I will never need
anywhere near 5hp on a mill. It has 32 spindle speeds and 32 feed speeds so
I really don't need a VFD. (The bridgeport head is a VS off some kind of
hydraulic driven mill)

I managed to start the mill motor using Hanrahan's self starting model,
but I needed about 12x 50 uf run capacitors to do it. According to
Hanrahan's article, it should only take 120-150 uf to start. I had to
remove the chain drive to get the motor to come up to speed. With the chain
on I could only get it up around 200 rpm (ran out of capacitors). The mills
electrical system contains all the essentials for Hanrahans RPC. I just
added the capacitors on the output of the contactor between line 1 and the
non-fed line 3.

Hanrahans RPC with the separate starting circuit using start caps calls
for around 50-100 uf per idler hp, yet the self starting version calls for
25-30 uf (per hp). Why so much more for the self starting version??

Wayne Sippola
Moose Jaw, Canada