Renovating a Hardinge HLV-H

[BillTodd]

I had to finish the worklight before I could post these :)


Progress has slowed while I'm awaiting the 240-415v step-up transformer to arrive from Airlink Transformers. Meanwhile, I've found another, much smaller and neater, Variable Frequency Drive to power the main motor ( A 1500W Siemans MM150).

I'm bidding on a couple of low power (100W) VFDs to run the coolant pump and speed change motors at the moment, with the intention to completely rewire the control box.

The plan is to use the interlocked pair of contactors (currently used to control the speed adjust motor) as a new speed selector relay. This new relay pair will only change speed (thus disconnecting the VFD) when the VFD is stopped. I'll keep the original speed change lever and switch, but it will be used at 24v to control the VFD.

I could use a microprocessor to control all this but, at the risk of being called a luddite, I intend to use simple relays in the interest of fixability (by others).

I'll post a circuit when I've worked out the details.