Evening all, nice out, isn't it?

I'm hoping to pick some brains, I recently acquired an ancient and abused
[1] Challenger lathe[2], mainly for the tooling and motor that came with it,
and I think I'd like to get it running to get back in the hang of machining
while I find what I'm actually looking for (a Holbrook would be nice...) at
a price I can afford!

Being a fan of skips, the dump etc. I came across an old Audi air-con pump
complete with electromagnetic clutch for two quid[3], dismantled it and
found it's pretty simple to adapt (apart from the spline in the hub, would
have to bore it and cut a keyway) - I believe that these are called on to
transmit upwards of 5HP (certainly putting 12V at 4A up it locked it pretty
firmly), it occured to me that I could use this as a drive clutch for the
3HP (eek! possibly a bit over-sized for a small lathe...) single-phase motor
that came with the lathe, on either the motor output shaft or the
countershaft-that-needs-to-be-built, can anyone see any glaringly obvious
snags that I haven't?

I've had the motor connection box open, and have sussed out how to reverse
it, should I want to, but would like the added safety of braking it - I've
seen a few references to DC braking, wonder if anyone has had any practical
experience of it? I assume that it's just a case of dumping Several Amps
into the motor coil and letting back-emf/induced current in the rotor drag
it to a halt?

Thanks in advance for any help!

Dave H.
--
(The engineer formerly known as Homeless)

"Rules are for the obedience of fools, and the guidance of wise men" -
Douglas Bader

[1] broken teeth on the bull gear (known weakness), missing backgear
shaft... may not bother fixing that can of worms
[2] 10" swing, 24" b.c, changegear screwcutting and longitudinal feed but
not many gears!
[3] and a pair of half-ton machine skates for another two quid )