Renovating a Hardinge HLV-H

[BillTodd]

Not much to photograph ATM, but...

I fitted a 4 jaw chuck (so I can make a backplate for a 3jc) which exacerbated the braking time problem; Essentially, the braking time for all speeds is determined by the time it takes from the highest speed, with the extra flying mass of the chuck I had to extend the brake time - I don't mind a ~6 second stop from 3000rpm, but the same from 125rpm is silly.

I emailed Siemens for advice on adding a braking resistor, to allow the VFD to brake harder, unfortunately my model VFD does not have the brake transistor fitted, so I can't do that. They were kind enough to suggest an alternative; an MM440 (@ £467), Keypad (£28), Brake resistor (£112 - expensive, even for a big resistor, I think) and a class A filter (£61). I thanked them for their help, but I won't be going down that road.

This morning I found, buried in among the 'JOG' parameters, in the Siemens VFD is an option to use the jog up/down ramp times instead of the normal ones; switching between the two settings with one of the digital inputs. A quick re-wire and now I have ~2s stop times from low speed and ~6.5s from High speed with chuck :)

It makes the whole lathe feel better. (must redo the youtube video)