Let's Talk VFD's

[William Batdorf]

Greetings All,

I recently scored a very nice Oliver wood lathe on a local school auction. I haven't yet got to the motor but I would be doubtful that it is any larger than 1-1/2 HP. Of course, it has a 3-phase motor and I don't have 3-phase power...not even along my country road. I don't wish to become an expert on VFD's, so I'm hoping one of the Creekers out there can tell me "go buy model XXX and you won't be disappointed". There seems to be lots and lots of off-shore manufacturers on-line. I'm suspicious of products that don't have a brand name. I'm not usually a lowest price buyer...The way my brain works, I'm wondering if it make sense to pick a make and model that would, say, handle up to 5 hp and use that one as a default standard for any future applications so the panel arrangement, operation, wiring, programming etc. is all consistent. That might be a fools errand, but I want to hear what you guys would do. A rotary phase converter install, while appealing, is not a practical solution at this point. I'm open to any and all suggestions. Thanks in advance.

[Albert Lee]

Greetings All,

I recently scored a very nice Oliver wood lathe on a local school auction. I haven't yet got to the motor but I would be doubtful that it is any larger than 1-1/2 HP. Of course, it has a 3-phase motor and I don't have 3-phase power...not even along my country road. I don't wish to become an expert on VFD's, so I'm hoping one of the Creekers out there can tell me "go buy model XXX and you won't be disappointed". There seems to be lots and lots of off-shore manufacturers on-line. I'm suspicious of products that don't have a brand name. I'm not usually a lowest price buyer...The way my brain works, I'm wondering if it make sense to pick a make and model that would, say, handle up to 5 hp and use that one as a default standard for any future applications so the panel arrangement, operation, wiring, programming etc. is all consistent. That might be a fools errand, but I want to hear what you guys would do. A rotary phase converter install, while appealing, is not a practical solution at this point. I'm open to any and all suggestions. Thanks in advance.

I have a VFD, it is a Danfoss VTL2880 series, I know it can limit the inrush current (which is what I am using it for) and/or change the frequency of the motor, I am not aware of it being used to convert single phase power to 3 phase or vice versa...

As far as VFD goes, I think you cant go wrong with Danfoss.

[Tom Trees]

I'm not too knowledgable about VFD's for lathes, but I believe you're after a specific one for your lathe compared to say a tablesaw or bandsaw,
as you need to have high torque at low RPM.
If I'm not mistaken, it is a "Vector" drive you're after, which won't have issue overheating things.
I fitted a pot before to my bandsaw for cutting plastic sheet, and the far Eastern VFD which is more than happy to run my saws without issue
didn't like it, and tripped out a few times, and took me some head scratching to figure out it was the pot (speed adjustment dial)
which was tripping out the drive.

Sorry can't give you a quick or good answer.
Best of luck
Tom

[Brian Holcombe]

A stand alone rotary is much easier than converting the machine to a VFD in my opinion. That said, I recently used. Hitachi WJ200 unit to allow a 3ph drill press to run on 120v. Small motor, still working out the details on the push buttons but I’m happy with how easily programmable
The hitachi unit is.

[Stan Blaszczyk]

In a single machine application a vfd is very simple and likely more cost effective to implement and you get the benifit of the frequency control. A rotary phase converter would be best for a multiple machine application or where balanced lines are required for a large cnc single phase power application (you would still need a vfd to control the spindle). With your application of a non-NC machine vfd set up is pretty straight forward and the only recommendation I would give is to get one with a knob (not button only) on the front so you can adjust speed easily. I have a 10hp eBay vfd on my single phase cnc for the spindle drive and it works great. The only issue I had was setting up the communication protocol to the machine controller(each manufacturer uses a different format). It just took a bit of trial and error with the manual.

don’t know if this helped but the size of vfd you are looking at is sub $100 and should not be an issue any way you go.

[Tom Trees]

Robert Minchin's free google document is the best information you will find on the subject regarding understanding what the parameters mean,
safe usage, and fitting a VFD
Pretty much the whole package for one to digest, and you will find information on Vector type drives there.

You will be able to hook up your swtchgear like start, stop, jog (pulse), reverse, and hook up a speed control knob and whatever else you want, say a breaking resistor
for instant braking if you wished.
Most of those things are standard on any VFD
bar the breaking resistor abilities which you might not want, as there is built in breaking anyway, this would be for huge 4' bowls or something that one might need that.

I will say that I cooked a VFD before when I bogged down my bandsaw, the motor got quite hot aswell.
so read up on vector drives
https://drive.google.com/file/d/1dBTVXxPUa4dTeCREIph-c0I4X8fdzdtS/view

[Patrick Kane]

I just bought a self-enclosed VFD from automation direct, and I love it. The whole thing is dust proof, easily programmable, things are labeled well and the manual came in English. Furthermore, the customer support is there in aces for you if you need it. Mine was for a 3hp Oliver 232, and my VFD was maybe $360 total?

I’ve purchased other VFDs and this one is head and shoulders above the rest.

[Terry Therneau]

Some of the Oliver lathes had multiple speed motors; a rotary switch chooses which winding to use. If that is the case using a VFD is harder; since it acts as the motor protection, as well as on/off, the VFD really wants to be direct to the motor, without a switch. A picture of the motor nameplate would confirm that.

I've used VFDs from ebay (used), new Chinese from ebay, and units from a regular US seller, and I vote for number 3. It will cost you more (around $200), but it is worth it. I still can't get my latest Chinese one to do variable speed correctly, since the manual is so bad as to be unreadable. Since it is on an edge sander I can get by on single speed, but for a lathe you will want variable. Look up Wolfe Automation, call them with the nameplate info on the motor (full load amps is more important than HP), and they'll tell you what to get. A 3 HP Fuji ( FRN0012C2S-7u) for instance is $232 and it's a great drive. Easy to read manual, and they'll answer questions if you get stuck (phone or email).

Wiring is pretty simple: 220 power to the VFD, 3+ground from VFD to the motor, and lightweight wire from a switch to the VFD control. I use speaker wire and an ordinary light switch for one of mine (dust collector, with multiple switches around the shop, wired the same way as a multi-switch light bulb), but for anything that can hurt me I use a switch that can be turned off without looking. Not the full 12" square STOP paddle you see in an OSHA shop, but the same idea. However, that is a personal choice.

Terry T.

[Bill Dufour]

The no name haung yang VFD I bought from ebay was typical of many. It had labelled brake resister terminals that did not electrically connect to anything on the other side of the circuit board. Many purchasers would use as is or even attach a brake resister and think it was doing something.
Bill D

[Curt Harms]

I have a VFD on a drill press. This was my first experience with them so went with a Teco-Westinghouse from Dealers Electric in north Jersey. I had it shipped but could drive to the seller's office if need be. The drill press required a new 3 phase motor as well. It was fairly straight forward, just required a modest amount of electrical smarts. The only programming I've done was to change the acceleration/deceleration times. The default was I think 10 seconds, I changed it to 3 seconds. At least with Teco-Westinghouse you can download the manual and get a feel for what you're getting into without spending a dime. Don't be intimidated by the 'advanced topics', you probably won't need them.

The question I would have would be regarding low RPM torque. I found with the drill press the really low frequencies really reduced the torque. I believe lathes sometimes require low RPMs (not a turner) so that would be something to check into. I don't know that lathes require high speeds so changing pulleys?

[Phillip Mitchell]

Another option is to order a VFD from Jack Forsberg and he or his partner Matt will literally talk you through each step of the parameter programming specific to the machine you have and what you want from it.

Last I remember, the 2 hp drive is around $250 shipped. He also has an optional remote control switch with a long cord that you use to control the on/off and frequency that you can conveniently mount in an easily accessible location and have the VFD out of sight. I’ve had a 5 hp drive of his on my Oliver jointer for about 3-4 years and am very happy with it.

As to the built in variable speed of the Oliver lathe, I don’t know how well that would play with a VFD or not, but you may find an answer on that searching on Owwm.org if not here.

[Jared Sankovich]

You can use a vfd on a multi winding (multi speed) motor. You just need to have the rotary switch between the motor and the vfd.

That generally is a big no-no. However if you only switch between windings when the vfd is idle there is no issue. It's not ideal in any way but it works. If you forget and switch under power you will let the magic smoke out.

My recommendation is the Fuji frenic line of vector drives. Fantastic manuals, and well designed features. Surprisingly reasonable price for a name brand product.

[Robert Hayward]

Another option is to order a VFD from Jack Forsberg and he or his partner Matt will literally talk you through each step of the parameter programming specific to the machine you have and what you want from it.

+ one on Jack and Matt. I knew nothing about a VFD when I ordered from Jack. Jack asked for a picture of the motor data plate and took it from there. After delivery Matt emailed and we set up a time for a phone call type installation. I had it all wired and ready to go prior to the actual phone call. Matt had me up and running in less than an hour and on a Sunday afternoon when it was convenient for me. Including being able to use the factory machine buttons for on, off and kill with the VFD mounted up high on a wall out of harms way. Matt's instructions were so thorough I believe I could have later done more VFD's with no help. Been a couple years now so I might need a little help today. My VFD also went on an Oliver jointer, the modern 10" one with a Baldor motor.

[ray grundhoefer]

go to a website called factorymation.com. Get yourself a teco vfd. I put one on my 3 hp dust collector was easy to wire up and works great.

[Jeff Bartley]

I have no first hand experience with VFD’s but I do have an Oliver lathe. William, does your lathe have a Reeves drive and a main power switch? I would definitely study the wiring of the lathe to make sure you get the connections correct. Otherwise, like Jared said, you see the magic smoke!

Also, let’s see a pic of that lathe!

[Tom Bender]

For my TS I went with a TECO VFD and a VFD rated TEFC motor. Not the cheapest option but solid. Good tech support too. After a few years the VFD died, probably lightning. Of course the replacement TECO was a little different but works well.

A motor only provides one level of torque and can stand rpm turndown to about 30% for a proper motor. And cooling is reduced. For a lathe which needs to deliver full torque at high and low speeds for long run times, keeping the motor at or near full rpm is best. And a wide speed range is needed, more than 30%. So mechanical speed reduction is required. Reeves drive or belt changes combined with a VFD is good.

[David Kumm]

If you need a wide speed range with a vfd, consider a vector duty motor. I have a Baldor TENV on my lathe that will deliver constant torque to -0- and can be run over 120 hz. The high end of course loses hp and torque but the motor is much better suited than the 25-75 hz range of a normal inverter duty motor. Having a back gear on a lathe helps a lot as does the reeves drive mentioned above. 3-5 hp Baldor IDNM or Marathon Black Max motors can be found used or NOS as many don't know much about them. I have two NOS Vector duty duty 5 hp motors that new cost in the 1500 range and both were under 400 delivered. Not a bad option. Dave

[Bill Dufour]

David those 5hp motors can I assume you are running them at 3hp or less? That way you get the hp at low rpm where it would be reduced.
Bill D

[ChrisA Edwards]

This might be of interest


https://www.youtube.com/watch?v=DJfiOqaeFDg

[scott lipscomb]

Here is my Oliver 159 with a VFD, Teco FM50, though I think that model has been replaced with another one. It works well.
466173

[Malcolm McLeod]

Lots of mentions of torque at low RPM, but keep motor cooling in mind as well.

Typically, I won't run a TEFC motor at less than 25% (15hz). This keeps some minimal air flow for cooling, and is suitable for motors at >80% duty cycle and >80% loading. ETA - Use some common sense here - 25%rpm/80% duty cycle/80% load won't fly if you put it in a 4sqft pumphouse in the Mojave. Keep sufficient air space around any motor :: don't bury it in sawdust and expect immortality.

If you need still lower spindle speeds than offered by 25% motor rpm, then you can either use mechanical reduction to spindle, or add supplementary cooling (i.e. a fan operating at its rated rpm).

[David Kumm]

David those 5hp motors can I assume you are running them at 3hp or less? That way you get the hp at low rpm where it would be reduced.
Bill D

I run with a full sized vfd. The 5 hp motor gives extra hp at the low end but still loses torque and hp at the high end. Without a reeves or a backgear. the motor size for a lathe is often doubled from what was originally offered to compensate for low and high limitations. Dave