Hardinge HC Spite Lathe

[Jehannum]

Purchased a '70s vintage Hardinge HC at auction. My bid was supposed to be a thumb in the eye of whoever won it, because usually tool auctions around here go to the moon, so I figured $1500 was reasonably low, so I'm calling it the Spite lathe.

Tested the spite lathe yesterday with a "digital phase shifter" from amazon and after repairing the rotary switch for speed range, reseating a wire in the brake solenoid switch, and fixing a switch detente spring, and it works almost perfectly. The only thing that doesn't work right now is the variable speed control motor, and possibly the coolant pump (didn't want to try running it dry).

Hardinge lathes from that era use a sheave pulley system for speed control, kinda like a CVT. When one of the speed control rheostats on the control panel is adjusted faster, the speed control motor turns a carriage (carrying the main countershaft) on a jackshaft towards the headstock, forcing the motor's belt deeper into the sheave pulley, forcing the countershaft to turn faster. The only wrinkle is that the motor itself has two three-phase windings, a 0.5HP and a 1HP. It has a switch lever on the front to go between those ranges (1 is low, runs on the 0.5 winding, 2 and 3 are high and run on the 1.0 HP winding, but have separate sheave pulley ranges). Anyway, I can hear relays clicking away in the cabinet when I turn the appropriate rheostat, but the jackshaft doesn't rotate.

I've just about convinced myself to give up on all of that, throw a VFD on the main motor's high power winding, figure out a 1 phase coolant pump, and a 115VDC converter for the power carriage and crossfeed motor.

It hurts a bit though, because it is so damn cherry in the electrical cabinet.

Here's where it will rest, once I figure out the electrical issues (currently working to move the material rack out to a shed).

 

[tool_scrounge]

Buy or build a rotary phase converter and be done with it. If you start with a used 3 phase motor it can be built for pretty cheap. It will fit nicely underneath the tanker desk to the right of the lathe. Then you can get more three phase powered tools for cheap and run them too.

As you know, VFDs do not want any switches or relays between it and the motor.

 

[Jehannum]

Buy or build a rotary phase converter and be done with it. If you start with a used 3 phase motor it can be built for pretty cheap. It will fit nicely underneath the tanker desk to the right of the lathe. Then you can get more three phase powered tools for cheap and run them too.

As you know, VFDs do not want any switches or relays between it and the motor.

At this point though, I don't know if the motor is dead on the speed adjuster or not, so I guess I should work that out before I go whole-hog either way.

 

[tool_scrounge]

You might consider wiring your static phase converter directly to the unloaded motor and see if both windings work. It is a pain I realize.

 

[TurnipTruck]

I thought @DocsMachine posted a Hardinge sheave drive lathe restoration series, but I can’t find it. Maybe Doc will post a link when he gets back from wombat emasculating class.

 

[RoninB4]

-Hope you get that sorted out. The Hardinge lathes, among a few others, were one of my preferred machines for that size work envelope.

 

[cvairwerks]

Should be able to find some good advice on dealing with the Reeves drive on it, over on Practical Machinist.

 

[DocsMachine]

[

At this point though, I don't know if the motor is dead on the speed adjuster or not, so I guess I should work that out before I go whole-hog either way.

-The speed control motor is 3-phase, too, and you're using a static phase converter. A static starts the motor with a burst of voltage from a set of capacitors to briefly simulate the third 'leg', but runs the motor on the two single phase 'legs'. The sheave motor relays aren't working because that leg isn't there to engage the relays.

As noted, you really need a rotary converter or a Phase Perfect. A VFD won't work unless you want to gut all the speed and reversing switching, so you need proper 3-phase.

I can easily recommend American Rotary for a phase converter- add up all the motor HP combined (pump, spindle, speed control) and pick up a rotary that's the next size up from that.

It'll be FAR easier and cheaper than trying to swap motors and buy VFDs...

Doc.

 

[Jehannum]

-The speed control motor is 3-phase, too, and you're using a static phase converter. A static starts the motor with a burst of voltage from a set of capacitors to briefly simulate the third 'leg', but runs the motor on the two single phase 'legs'. The sheave motor relays aren't working because that leg isn't there to engage the relays.

As noted, you really need a rotary converter or a Phase Perfect. A VFD won't work unless you want to gut all the speed and reversing switching, so you need proper 3-phase.

I can easily recommend American Rotary for a phase converter- add up all the motor HP combined (pump, spindle, speed control) and pick up a rotary that's the next size up from that.

It'll be FAR easier and cheaper than trying to swap motors and buy VFDs...

Doc.

I'm not certain that I'm using a static phase converter. They lay claim to being a low-cost clone of the phase perfect stuff. When the motor is running, there is 208V between each of the legs.

in any case, if I keep that to run the coolant pump, put a VFD on the 1HP spindle motor winding (or keep the drum switch to swap between .5 and 1 and put it in before that), and put a 90VDC rectifier in, it gets everything but the speed range motor running, but I get speed control through the VFD by default, and it's about $500 less than American Rotary.

 

[tool_scrounge]

I'm not certain that I'm using a static phase converter. They lay claim to being a low-cost clone of the phase perfect stuff. When the motor is running, there is 208V between each of the legs.

phase perfect: $3800 and weights 102 lbs for the up to 7.5hp version

American DPS Digital Phase Converter 7.5HP​

$170, weighs 3 lbs.

from what I can find, it is a digital controlled static phase converter.

 

[DocsMachine]

I'm not certain that I'm using a static phase converter. They lay claim to being a low-cost clone of the phase perfect stuff. When the motor is running, there is 208V between each of the legs.

-I'm not familiar with those, but keep in mind that if it were a static, and the motor were running, you'd be getting voltage on all three "legs" simply because the motor itself is generating the third. (Which is of course how a rotary converter works.)

in any case, if I keep that to run the coolant pump, put a VFD on the 1HP spindle motor winding (or keep the drum switch to swap between .5 and 1 and put it in before that), and put a 90VDC rectifier in, it gets everything but the speed range motor running, but I get speed control through the VFD by default,

-Just keep in mind that the VFD doesn't like switches between it and the motor. You can have the high-low control, and just be sure the motor is off before switching speeds.

I'd personally recommend keeping the stock Hardinge controls, well, stock. They're very handy and intuitive, especially for turret work- which is what that machine is. Fast speed switching for drilling, instant reversing for threading, etc.

Doc.

 

[Jehannum]

-I'm not familiar with those, but keep in mind that if it were a static, and the motor were running, you'd be getting voltage on all three "legs" simply because the motor itself is generating the third. (Which is of course how a rotary converter works.)

-Just keep in mind that the VFD doesn't like switches between it and the motor. You can have the high-low control, and just be sure the motor is off before switching speeds.

I'd personally recommend keeping the stock Hardinge controls, well, stock. They're very handy and intuitive, especially for turret work- which is what that machine is. Fast speed switching for drilling, instant reversing for threading, etc.

Doc.

If I'm getting volts on all three legs because of the main motor backfeeding, then the motor for the speed change drive is surely borked, as it'd be getting the same.

I'll likely wire the VFD to the high speed winding, knowing what I know now, and use the speed control from the VFD, as it'll provide just as fast switching and reversing as the electromechanical stuff that was there originally.

The threading is a different ball of wax, as it doesn't have the threading attachment, or a lead screw. That'll likely be another bit of electronics, with one of the Clough42 electronic lead screws.

I'm not planning to trash anything that I can't put back to stock in the future, for sure.

 

[DocsMachine]

The threading is a different ball of wax, as it doesn't have the threading attachment, or a lead screw. That'll likely be another bit of electronics, with one of the Clough42 electronic lead screws.

-Actually, it's a turret lathe. I was thinking releasing tap holders and die heads.

Doc.