Motor swap and VFD conversion for a Hardinge HLV

[dkmc]

As per DKMC don't over think it

The last Hardinge HLV-Hs had 5hp motor and VFD instead of the variator , essentially it could give about the same [edit] 50% more torque as the 0.5hp low range winding at the 100rpm minimum speed . Above that minimum it would have had a bucket load of power .

1332A_HLV.pdf

drive.google.com

Some years back I did a cnc gang tool retrofit on a Hardinge Chucker. Took out the VS drive, and fit a 5hp 1750 motor and 5hp VFD. Moved the motor plate up, cut Poly-V grooves in the OEM spindle pulley for a shorter direct Poly-V drive. External braking resistor. 4000 RPM max. Able to tap 3/8-16 in steel @ 200 rpm, no issues. 0-4000 and 4000-0 in 2.5 seconds. I'd expect the same performance with a similar equipped HLV.

The other thought is, how many people put 6 or 7" diameter parts in a HLV-H, and need to take 1/8" or 3/16" deep cuts at 150 rpm? Not what the machine was designed for. Use a larger engine lathe for such work.

 

[max.levesque]

Why did you decide to move the motor plate up, instead of using a longer belt ?

Also, can the spindle belt be replaced without removing the spindle and bearings ?

I've read so many warnings regarding spindle bearings removal, I don't remember exactly what they were, but apparently it's not for beginners !

What do you think of using a link type belt from the spindle all the way down motor pulley, to avoid removing the spindle, and to keep the motor plate where it is ?

Some years back I did a cnc gang tool retrofit on a Hardinge Chucker. Took out the VS drive, and fit a 5hp 1750 motor and 5hp VFD. Moved the motor plate up, cut Poly-V grooves in the OEM spindle pulley for a shorter direct Poly-V drive. External braking resistor. 4000 RPM max. Able to tap 3/8-16 in steel @ 200 rpm, no issues. 0-4000 and 4000-0 in 2.5 seconds. I'd expect the same performance with a similar equipped HLV.

The other thought is, how many people put 6 or 7" diameter parts in a HLV-H, and need to take 1/8" or 3/16" deep cuts at 150 rpm? Not what the machine was designed for. Use a larger engine lathe for such work.

 

[Mark Rand]

What do you think of using a link type belt from the spindle all the way down motor pulley, to avoid removing the spindle, and to keep the motor plate where it is ?

Pretty sure that no one makes link belts in the profile used by the variator/reeves Drive that the Hardinge lathes use.

The belt change procedures are documented out there on the interwebs and in the Hardinge manuals.

 

[dkmc]

Why did you decide to move the motor plate up, instead of using a longer belt ?

Also, can the spindle belt be replaced without removing the spindle and bearings ?

I've read so many warnings regarding spindle bearings removal, I don't remember exactly what they were, but apparently it's not for beginners !

What do you think of using a link type belt from the spindle all the way down motor pulley, to avoid removing the spindle, and to keep the motor plate where it is ?

A 4ft center distance on a 1" wide poly-V belt is a harmonic symphony waiting to happen. Moving the plate up was worth the effort.
On the Chucker no need to remove spindle bearings.
Those link belts might be less precise than either a poly-V or the OEM hardinge belts. And that long, it might cause much vibrations and harmonics. Perhaps a couple idlers half way would help? But just as much or more work than moving the plate.

 

[max.levesque]

I'm now convinced that installing a 5hp motor makes the most sense.

I went on emotorsdirect.ca, and the criterias are encoded in the following link, which gives 18 candidate motors :

Search Store - Page: 1 | eMotors Direct

www.emotorsdirect.ca

I don't see much differences in the spec sheets, but perhaps I'm not looking at the right ones, prices range from $500 to $1200, are there any at the lower end of the price range that are good choices ?
Any brands I should chose or avoid ?

I hope my questions are not too much of a disturbance, and I want to thank everyone for their inputs !

For the VFDs, I think i'll manage to do my homeworks alone ;-) I find that with their feature lists, programming manual, spec sheets, etc, it is easier to get an impression of their quality.

A 4ft center distance on a 1" wide poly-V belt is a harmonic symphony waiting to happen. Moving the plate up was worth the effort.
On the Chucker no need to remove spindle bearings.
Those link belts might be less precise than either a poly-V or the OEM hardinge belts. And that long, it might cause much vibrations and harmonics. Perhaps a couple idlers half way would help? But just as much or more work than moving the plate.

 

[dkmc]

I'm now convinced that installing a 5hp motor makes the most sense.

are there any at the lower end of the price range that are good choices ?
Any brands I should chose or avoid ?

Craigslist, Marketplace, and my favorite......scrap yards, for lowest end good choices.
Not kidding. Doing things the easiest & lowest cost way has always been more fun for me anyway.

 

[max.levesque]

Craigslist, Marketplace, and my favorite......scrap yards, for lowest end good choices.
Not kidding. Doing things the easiest & lowest cost way has always been more fun for me anyway.

That's always my first choice, but I'm a bit eager to get that lathe running, and even though there's a constant flow of motors on marketplace, I haven't yet seen one that has all the right specs (230v, 5hp, 3 -phase). So getting one delivered on my doorstep in the next few days is very tempting !

 

[beckerkumm]

I've lost track of whether you are leaving the variator installed? 5 hp with the variator is a lot and way more than the machine was intended to push so you do want the vfd to limit the output. Without it, 5 hp is a good choice but as I posted earlier, the hz range you want is very wide so a vector duty motor is much superior at low speed to a regular inverter duty motor like the Baldor ECP. With the variator, decent 3 or 5 hp motor ( both have the same frame ) that you get a deal on will work. Teco makes a decent motor. the smaller Leeson are Chinese but decent as well.

Dave

 

[max.levesque]

I've lost track of whether you are leaving the variator installed?
Dave

I was going to leave the variator, but it would only function as an intermediary pulley shaft from the motor to the spindle. I would adjust it only once, so that the RPM range of the motor (ex. 0 to 1800), translates into a spindle RPM range of 0 to 3000. Then all speed variations would be done with the VFD.

The reason I would do this, instead of linking the motor pulley directly to the spindle, with a motor pulley of a diameter to achieve the same ratio:

1. I don't have a lathe to make the pulley (my other lathe is also not functional, waiting for the Hardinge to make it's missing part ;-) )
2. I can keep the current spindle belt. This might sound dumb, but for my 1956 HLV, the only way to change the spindle belt is to remove the spindle, *AND the bearings*, and I've read so many warnings that this was NOT a "beginner friendly" operation !
3. I can always remove the variator later if later chose to.

 

[beckerkumm]

If I had a working variator, I at least use it partially. A standard duty motor has a constant torque speed ratio of 10-1 and that is what I'd use with at least some variator adjustment to limit the hz range needed on the motor. Without a variator, a Vector duty motor with a 100-1 or 1000-1 CTSR gives consistent torque over a wider range. I've found NOS vector motors fairly cheap but they run in the 1500-2000 range at retail vs a standard duty 3-5 hp runs 500-750. I run a 5 hp AB CM202 ( same as Baldor IDNM 3665T ) on my Smart Brown 1024 with a 4-1 speed reduction through a clutch and while the motor is really sweet, smooth, and quiet, I keep the flat belt a tad loose so as to not overwhelm the machine if I get into a problem. You need to be careful that the motor torque is matched to the drive train. Someone here mentioned you can also program the vfd to limit output. A working variator really gives you a lot of motor choices. Unless I got a screaming deal on a 5 hp, I'd go 3 with a variator. You will only use the variator at the extremes but still nice to have.

Dave

 

[dkmc]

If I had a working variator, I at least use it partially. A standard duty motor has a constant torque speed ratio of 10-1 and that is what I'd use with at least some variator adjustment to limit the hz range needed on the motor. Without a variator, a Vector duty motor with a 100-1 or 1000-1 CTSR gives consistent torque over a wider range. I've found NOS vector motors fairly cheap but they run in the 1500-2000 range at retail vs a standard duty 3-5 hp runs 500-750. I run a 5 hp AB CM202 ( same as Baldor IDNM 3665T ) on my Smart Brown 1024 with a 4-1 speed reduction through a clutch and while the motor is really sweet, smooth, and quiet, I keep the flat belt a tad loose so as to not overwhelm the machine if I get into a problem. You need to be careful that the motor torque is matched to the drive train. Someone here mentioned you can also program the vfd to limit output. A working variator really gives you a lot of motor choices. Unless I got a screaming deal on a 5 hp, I'd go 3 with a variator. You will only use the variator at the extremes but still nice to have.

Dave

Lets see.....use a $1500 3hp 'fancy' motor to make up for lost torque, but a regular much-lower-cost more common 5hp motor would be too much power? That's confusing.

IMO the typical Hardinge spindle/headstock on any HLV/HC/xx59 can easily handle 5hp and even 10hp. The HLV carrage/cross slide assembly might not. But again, who's taking .250-.300 deep cuts on a HLV? I have a cnc lathe with a very similar (to the Hardinge) 5C spindle, the 8hp OEM DC drive blew up years ago, and I replaced it with a 15hp AC motor and VFD, no issues in 15+ years of use so far.

 

[max.levesque]

Interesting..., my first thought was that speed variation via mechanical means (like changing pulley ratios with the variator), made life much easier for the electronic side (VFD and motor), and allowed powering with more modest means. Then I figured, why not go overkill with an 5hp and leave options open, given that 5hp motors are not that much more expensive.


Now I started to explore the "unconventional territory", with servo motors, because why not ;-)

I'm particularly impressed by this motor:

https://teknic.com/model-info/CPM-MCVC-N1434P-RLN/?model_voltage=230VAC1ph

The ClearPath-MCVC model is used mainly for velocity (speed) control replacing AC induction motors, synchronous motors, DC motors, and more expensive (and non-integrated) servo systems. But it also has a torque mode,...

This video shows all the features, for applications where speed control is the main requirement:

If I had a working variator, I at least use it partially. A standard duty motor has a constant torque speed ratio of 10-1 and that is what I'd use with at least some variator adjustment to limit the hz range needed on the motor. Without a variator, a Vector duty motor with a 100-1 or 1000-1 CTSR gives consistent torque over a wider range. I've found NOS vector motors fairly cheap but they run in the 1500-2000 range at retail vs a standard duty 3-5 hp runs 500-750. I run a 5 hp AB CM202 ( same as Baldor IDNM 3665T ) on my Smart Brown 1024 with a 4-1 speed reduction through a clutch and while the motor is really sweet, smooth, and quiet, I keep the flat belt a tad loose so as to not overwhelm the machine if I get into a problem. You need to be careful that the motor torque is matched to the drive train. Someone here mentioned you can also program the vfd to limit output. A working variator really gives you a lot of motor choices. Unless I got a screaming deal on a 5 hp, I'd go 3 with a variator. You will only use the variator at the extremes but still nice to have.

Dave

 

[beckerkumm]

I didn't mean to confuse or get into the mud here. I understand and agree that with no variator, you typically oversize the motor to deliver low end torque and end up with more hp on the top end than the machine may have been designed for. The Hardinge may be able to cope but someone with little experience needs to be aware. A variator even if used partially eliminates the need for better speed control on the low end and the need for additional hp on the high end.. I do understand that if you are aware of the possible issues, a 5 hp motor will work either way and gives you some flexibility if the variator craps out. In that case I'd not go the extra route of the vector motor. I've been lucky and sourced two 5 hp and one 10 hp vector motors for less than $350 each delivered but it is getting harder to find them since Covid. I did find two NOS Baldor ECP 5 hp( for use on a gear head lathe and vfd ) this year for $200 each so it is still possible.

Dave

 

[jccaclimber]

I've found at least one brochure from a later HLV-H that lists a 5 hp motor, and seems to imply VFD control. If Hardinge thought it was sufficient I'm inclined to agree. My Sharp clone is also a 5 HP motor on a VFD, and it's mounted halfway up the cabinet, not on the floor. The motor does have a somewhat noisy built in fan to avoid overheating at low speeds. There isn't the seemingly instant switch between high and low speed that you get on a native 3 phase machine (I'm also running the VFD derated on 240V residential input), but it's still pretty quick. The high/low switch simply redirects an input to the VFD to command different speeds rather than swapping windings. Braking speeds (with a braking resistor) seem similar to an actual HLV-H though I haven't timed either and have only used one HLV-H.
One perk of the VFD is that it was set up with a knob to change the ratio between high and low speeds. I usually leave mine closer to 2.5:1 or 3:1 rather than the 2:1 original. Wouldn't make or break my decision, but it is nice. One downside is that mine reads actual spindle speed from the VFD, so I don't know what speed it is until I turn it on. Not a big deal, I don't often have it over 2k rpm (can do 4k), so there's not a big risk of leaving it set at 4k, forgetting, putting on a chuck, then overspeeding it. If I'm not sure a quick start in low speed answers the question as well.

If I already had a mechanical drive in good condition I'd certainly consider keeping it. A 1 hp motor and drive are cheaper than a 5 hp drive, and 5 hp drives that run on 240V split phase are less common. The VFD that came in mine is a Yaskawa, though a recent chat with them advised that one of their microdrives would likely be sufficient for this application, and they're much lower priced than their fully featured drives.

 

[max.levesque]

I've found at least one brochure from a later HLV-H that lists a 5 hp motor, and seems to imply VFD control. If Hardinge thought it was sufficient I'm inclined to agree. My Sharp clone is also a 5 HP motor on a VFD, and it's mounted halfway up the cabinet, not on the floor. The motor does have a somewhat noisy built in fan to avoid overheating at low speeds. There isn't the seemingly instant switch between high and low speed that you get on a native 3 phase machine (I'm also running the VFD derated on 240V residential input), but it's still pretty quick. The high/low switch simply redirects an input to the VFD to command different speeds rather than swapping windings. Braking speeds (with a braking resistor) seem similar to an actual HLV-H though I haven't timed either and have only used one HLV-H.
One perk of the VFD is that it was set up with a knob to change the ratio between high and low speeds. I usually leave mine closer to 2.5:1 or 3:1 rather than the 2:1 original. Wouldn't make or break my decision, but it is nice. One downside is that mine reads actual spindle speed from the VFD, so I don't know what speed it is until I turn it on. Not a big deal, I don't often have it over 2k rpm (can do 4k), so there's not a big risk of leaving it set at 4k, forgetting, putting on a chuck, then overspeeding it. If I'm not sure a quick start in low speed answers the question as well.

If I already had a mechanical drive in good condition I'd certainly consider keeping it. A 1 hp motor and drive are cheaper than a 5 hp drive, and 5 hp drives that run on 240V split phase are less common. The VFD that came in mine is a Yaskawa, though a recent chat with them advised that one of their microdrives would likely be sufficient for this application, and they're much lower priced than their fully featured drives.

The 5hp motor solution seemed like the best choice, but then I stumbled on a "like new" 2HP Baldor SuperE motor at 1/5 the cost, at 20 minutes driving distance, and bought it.

According to the calculations below (based on the principle that HP degrades proportionally to RPM below 60hz), the 2hp motor "becomes" a 0.5HP, once it's at 438 RPM

Hz	RPM	HP
60	1755	2
30	877.5	1
15	438.75	0.5
7.5	219.375	0.25

So, it's actually a slight improvement (in terms of HP at low RPM), over the stock motor, that has 0.5HP at 530 RPM written on its plate for low speed configuration.

Now, I'm going down the VFD choice "decision tree".

The Dura Pulse GS23-25p0 seems very will thought out. It's packed with features, the manual inspires confidence. : https://www.automationdirect.com/ad...y_drives_(vfd)/general_purpose_vfds/gs23-25p0

If I could somehow predict I will be forever happy with the 2HP motor, I would get it with no second thoughts.

The downside, is that it's derated to 2.5HP when fed with single phase input, and should I ever want a bigger 5hp motor and stumble on great deal for one, I'll have to replace the VFD, and my 2.5HP will have been an expensive "temporary" solution.

If on the other hand, it turns out that 2hp does every thing I want, then the DuraPulse VFD will have been an excellent choice.

As a hobbyist who doesn't have to be "productive" (taking aggressive cut make things faster), I'm inclined to think that a "low power" lathe will suite me just fine, and that if the stock motor was "good enough" for tool room machinists in 1956 when the lathe was designed, it should be plenty good enough for me !

Another reason to think that I'll be happy with low power, is that I obsess much more about precision that I do about productivity, in fact my obsession with precision is probably anti productive to the point that I would get me fired if I was on a payroll !

 

[dkmc]

You're gonna wish you had 5hp.

 

[max.levesque]

You're gonna wish you had 5hp.

Possible !

And now that I've looked around, I noticed that good deals on 5hp motors are more common than I thought.

As for VFDs, it's another story, the ones that can drive a 5hp while fed single phase current are pretty expensive, unless I get one of the Chinese brands that sell on amazon, and I've read plenty of warnings about those.

 

[dkmc]

I have several of the cheep-azz EBAY VFD's running with no issues. Oldest is just under 5 years.
Step up one size if it worries you, > 5hp motor, 7.5hp VFD

 

[jccaclimber]

A 2 horse motor and VFD is probably fine if you put it behind the original transmission.

 

[max.levesque]

I have several of the cheep-azz EBAY VFD's running with no issues. Oldest is just under 5 years.
Step up one size if it worries you, > 5hp motor, 7.5hp VFD

I have nothing against going cheep-azz, in fact I'm quite tempted by this ATO 5HP : https://www.ato.com/5hp-vfd
judging from the manual, it seems pretty good : https://www.ato.com/Content/doc/gk3000-variable-frequency-drive-user-manual.pdf

Besides being half the cost of a DuraPulse, it could power my 2HP, and give me the option of waiting for a great deal on a 5hp to show up.

If anyone here has any experience with the ATO brand, I'm listening !