Hardinge KL-1

[pauly45]

Everything seems to be fine with the main motor. No nasty noises.
The VFD indicates about 2A when running.

Now to re-do the wiring.

I wanted to use as many of the original switches and contactors as possible, but knew that most of the wiring would have to go.

The control box wiring looked like this when purchased:



I'll keep the original high/low speed switch, main power switch, and as many of the contactors that I need.
Wiring from the terminal blocks at the bottom will stay, and I'll just wire the new control into them

So, here is some of the top half removed. The new transformer mounted, together with two of the VFD's.
The top grey one is the FR-D740 for the main motor, the white one to the right is for the speed change motor.

[pauly45]

Well, the wiring is pretty much finished now.

There's a little tidying that's needed, but here is the control panel.
The original 'green' power on, and forward/reverse switches do the same job as before.
Theres a red indicator for the 240V_ac being available.
The small LED next to the forward/reverse switch is off when the main motor VFD is at 0Hz.
Theres a key switch to really make sure it can't be turned on accidentally.

I've put two fans in the front to get blow some air circulation in through the VFD's, and when I can get to the rear, I'll put two more in to suck air out of the cabinet.


And the cabinet wiring.



I think it functions quite well. I like the fact that I don't have to fiddle around with the vfd controls to work it, and overall, the lathe feels just like it would if powered from 3 phase.
The original lathe forward/reverse, high/low speed, faster/slower and pump on/auto switches all work the vfd's
The only thing I have yet to sort out is the brake.

A small niggle is that it is possible to have the high and low speed contactors trying to be on at the same time if I move the lever from high to low before the vfd has reached 0Hz.
It's not a big problem as they are interlocked so they cannot actually be on at the same time, but they buzz a bit if I don't wait until the motor has stopped.
Something to figure out later I think !

As soon as I can figure out how to save the circuit diagrams in sufficient detail, I will post them up.

[pauly45]

In the last photo of the previous post, in the bottom left is the inductor that's between the 240V_ac to 415V_ac transformer and the main motor vfd.

Based on the modelling, it's wound to be approximately 11mH.

The laminations are from a microwave oven transformer!
These transformers are great since they are an E-I configuration, welded together.
The weld can be carefully ground away to open up the laminations and get the original windings off. And the new ones on.

It is now gapped slightly, and held together with the clamps.

Unfortunately, it makes no noticable difference! Which I guess is good.
Only if I was to measure the current should I see a reduction in the peaks, otherwise I have to assume it is doing what the modelling says it should do...

[pauly45]

I've also decided upon some paint for the bits of the lathe I have cleaned up.

Trials of various paints seems to show this stands up well to the cutting fluid I have.

The paint is P383 Hi-Gloss one pack Polyurethane, manufactured by NEXA Autocolor.
I've gone for "Gun Metal Grey", code 2758.
Costs £26 per litre.

It's brushable, but can be sprayed if needed. although it brushes very nicely.

I'll let you know how it stands up to use!!

The collet closer is the first non-electrical bit I cleaned up and painted with the polyurethane.
From these grubby bits:


To this: