Anybody using a VFD and 1hp motor?

[doug kawallski]

I have access to a 1hp three phase motor and have been considering putting it and a variable frequency drive in place of the single phase 1 hp motor currently on the lathe. My only reason to do this is for lower speeds. I have been reading different posts about vfd's and reading spec sheets. Between all of these there is a lot of information to absorb. Rather than try to extrapolate from all of this whether or not I will get adequate power at low speeds I thought I would just ask those who may be running this configuration. I know some folks have replaced the motor with a higher horsepower model when installing a vfd to improve low speed performance and I am curious if that was a necessity or just that Tim Taylor instinct kicking in. As stated previously it would be a 1 hp motor. The lathe has a Reeves drive which will let me run down to about 350 rpm with the current motor. I do turn the occasional 10 or 12 inch bowl and while I do not need unlimited horsepower I do not want it to bog down either. Please let me know your experience.

[Reed Gray]

I know there were old lathes with 1 hp motors and 3 phase motors. Seems like they had the reeves drive as well. If I was going that route, I would get rid of the reeves drive and put in pulleys. Not sure how that could be done though. Need an electrical friend and a tinkerer master.

robo hippy

[Mike Cruz]

My understanding is that there are good and bad Reeves drives. Mainly, that depends on the manufacturer. Powermatic's Reeves drives are good. I would expect HF and Grizzly's to be not so much.

If your swing is 12", and you have Reeves drive that will bring you down to 350rpm, I don't think you'll have too much issue with slowing down past that with the VFD (power wise). I mean, how slow do you need to go? And for what? You shouldn't need to go TOO much slower than 350 for a <12" bowl. Unless you doing for slow speed sanding...but then you don't need all that much torque.

Bottom line is that when you reduce the torque by slowing down with a VFD, that just means you can't hog out. You can still make light/normal cuts.

I suppose I should have asked this earlier, but what lathe are you turning on? Depending on the lathe, even if the motor is free, purchasing a VFD and putting both of these onto a lathe isn't "worth" a lot might not be cost effective. Kinda like tricking out an AMC pacer, if you get my drift. Hey, and I don't mean to offend you (or anyone else)... If you are turning on a small/old/junky lathe, that's okay. Just don't know that it is "worth" it to put the motor and VFD on it.

[doug kawallski]

Mike, the motor is basically free. It came with another machine that I bought for other parts. The lathe is a Powermatic model 90 and I guess I had a couple of objectives in mind. The Reeves drive on the Powermatic is bullet proof but a little stiff on the deceleration and a little inconvenient for starts and stops. I thought if I could find a VFD for a reasonable price I could quite often use it to go from stop to the desired speed without touching the Reeves drive. As a perk I could get some slower RPMs if I ever wanted them. I have seen so many wood turners praising this sort of mod that I thought there must be something to it. If I don't do this mod I will likely spend the money on some Cragar Mags for the Pacer.

[Roy Turbett]

Mike, the motor is basically free. It came with another machine that I bought for other parts. The lathe is a Powermatic model 90 and I guess I had a couple of objectives in mind. The Reeves drive on the Powermatic is bullet proof but a little stiff on the deceleration and a little inconvenient for starts and stops. I thought if I could find a VFD for a reasonable price I could quite often use it to go from stop to the desired speed without touching the Reeves drive. As a perk I could get some slower RPMs if I ever wanted them. I have seen so many wood turners praising this sort of mod that I thought there must be something to it. If I don't do this mod I will likely spend the money on some Cragar Mags for the Pacer.

I have two Powermatic 90's with 1 hp 3 phase motors and vfds and do just what you want them to do. I added riser blocks to both of them and don't have any trouble rounding out 15" bowl blanks. Check out OWWM.org and you will find multiple posts on the Powermatic 90 including Mike's rebuild and several of mine.

[Dale Winburn]

I had a 1 HP 3 phase motor and a VFD on my old Delta for over three years, it also had a 4 step pulley system, worked great. I just bought a new ONEWAY 1224, it has a 1 HP 3 phase motor with VFD. I'm in the process of replacing the 1 HP motor on my home built bowl lathe with the 3 phase motor and VFD from the old Delta. The bowl lathe also has a 4 step pulley system, should give me a wide range of torque vs speed. It will be nice to have variable speed on the bowl lathe.

[Mike Cruz]

Doug, the Reeves drive on your PM90 should be a good one. What year is it? That will determine if it has the jackshaft. Like Roy said (he's done the rehabs, too), look at my and his threads on our PM90s. I don't have mine anymore. But, honestly, I loved the ability of changing the speed with the Reeves drive for 350 to max, and using the pot for slower than 350.

On the start/stop issues. I disconnected the switch in the headstock that requires you to have the Reeves drive in the start/stop position. That was a major PITA to have to always do each time you wanted to start or stop the machine. PM90s were built to be in schools. That safety feature was to prevent a kid from walking up to the lathe with a 12" blank, mounting it, and turning on the lathe without checking the speed control (you know, how it was still set to 3000 rpm from the last kid that was turning a spindle). Well, I'm not a school, and I pay attention to the speed that my lathe is set to. So, I didn't need that "safety" check.

[Dennis Ford]

If you keep (and use) the reeves drive; 1 hp will be adequate. By keeping the motor rpm up and using the reeves drive, you will have a lot of torque.

[doug kawallski]

I really appreciate the feedback. Any recommendations on brands for a reliable but not too expensive vfd?

[Dennis Ford]

I prefer Hitachi drives.

[Roy Turbett]

I really appreciate the feedback. Any recommendations on brands for a reliable but not too expensive vfd?

I don't know that brand matters all that much but you will want to make sure the VFD is rated for at least the hp of the motor. I bought a used Reliant VFD that is rated for up to a two HP motor on Craigs List for $60 that works fine with a 1hp motor. My second one is a new Teco that I paid around $150 for and is rated for up to a 1 HP and works equally well. Check out the "Everything Electrical" section at OWWM.org and search "VFD". You will find all kinds of information on what to look for in a drive. You will also find different ideas on where and how to mount the drive, external controls, etc. I have mine set up with external on/off/fwd/rev switches mounted in magnetic boxes that I can position anywhere on the lathe. Some guys also put a potenometer in an external box and skip the fwd/rev. I only use rev. for sanding at slow speeds.

[Roy Turbett]

On the start/stop issues. I disconnected the switch in the headstock that requires you to have the Reeves drive in the start/stop position. That was a major PITA to have to always do each time you wanted to start or stop the machine. PM90s were built to be in schools. That safety feature was to prevent a kid from walking up to the lathe with a 12" blank, mounting it, and turning on the lathe without checking the speed control (you know, how it was still set to 3000 rpm from the last kid that was turning a spindle). Well, I'm not a school, and I pay attention to the speed that my lathe is set to. So, I didn't need that "safety" check.

My other PM 90 (yes, I have three of them) is a 1 hp single phase motor without a VFD. I kept the safety micro-switch on that lathe because the motor will immediately accelerate to full speed which may not give an aging baby boomer like me enough time to react should something be wrong. I don't need this feature with the lathes that have VFD's because I programmed them so it takes 5 seconds to accelerate to full speed. It also takes 5 seconds to decelerate. Unlike Mike, I have friends that come over on Friday and Saturday mornings who also use the lathe.

[Mike Cruz]

The TECO FM50 is a great VFD that works great for this application. Factorymation.com has them. I think, for a 1 hp motor, they run about $100-125.