Holbrook Minor DC moor speed controller

Hi,
I had first posted this request for help in the Sales forum by mistake, and although I got one answer, I'm hoping to get more details here, my not being electrically knowledgeable.
The controller is toast, burnt all around and shorted internally, needing replacing.
I found one on E-bay for 300$, but wandering if there are alternatives as Thermite assured me, and at cheaper prices.

Anyone knows of a source? It's identical to the older HLV-H except for voltage: 240-280vac, 2.25 amps max, to control a 200vdc, 1.5 amp., 3500rpm and about 1/4hp. motor.

Thanks a lot.

Have you joined the holbrook group I O ? There are a couple of Hobrook Minor owners there who seem to have a lot of experience tearing into their machines. Dave

Good morning Thermite,
That is one complete and nice answer, but not being an electrician, I soon got lost in the terminology; as an example, I hired a commercial electrician to hook up the phase converter, transformer, switch boxes, add a relay and fuses for the coolant pump; 10 hrs. later and 1,000$, the lathe doesn't work' the overload heaters in the 240v box, kept melting; so he installed bigger ones; now the forward contactor arcs and rattles rapidly; all voltages are within limits and properly hooked up; so he went away scratching his head. I then called the guy that had sold me the transfo. for my HLV-H which, by the way works the Holbrook nicely; within seconds of explaining my dilemma, he tells me my transformer is hooked up backwards: what I have is as commercial transformer, meant to hook it up to a 600vac shop supply, to give me a 240v output for a motor that runs on that; so your voltage is too high, hence the arcing etc.I need a step-up transformer, which I'm still looking for.

So, I ordered the only available variac. on E-bay; at least that should work.
Thanks again for the explanation: like you said, you've been pushing electrons too long, and I've been pushing wrenches too long
Best regards, Herman

beckerkumm said:

Have you joined the holbrook group I O ? There are a couple of Hobrook Minor owners there who seem to have a lot of experience tearing into their machines. Dave

Click to expand...

I am a member of that group, but there's not much action on that site; the last post regarding the Holbrook Minor, goes back to May...

Also, you're not allowed to post any picture of your lathe unless it's a Holbrook; had one of my picture removed... I much prefer this site, as it is a user friendly site, and lots of knowledge to be had.
I'm just a hobbyist, having fun renovating whatever turns me on; I've never had a machining course ( none available); my bits of knowledge comes from watching videos, and reading this site...
Thanks for the suggestion,
Cheers,
Herman

Your challenges are inside the Holbrooks "zone".

So it is akin to asking a tires, wheels, brakes, and suspension guru to sort ... the motor's ignition or fuel injection system.

He may, or may NOT, understand those bits.

Seems to me this particular one got it badly enough wrong, you'd best start-over. There can be damage, and in more than one place.

Best if you can enlist the aid of a person - IN Blighty - who is more experienced with the whole-Holbrook.

Specifically.

Thermite,
As I mentioned, the lathe works well with the Hardinge power supply, except for the DC motor, awaiting the autotransformer.
The other issue, is the spindle only runs in the reverse selection: the electromagnetic clutch for forward, is inop. That clutch is inside the 2 speed gearbox, which will require the motor/gearbox removal; that is a wrench job; hopefully, I can save the clutch...