220v w/VFD or new 110v motor for lathe?

[Splat]

My new-to-me SB Heavy 10 (actually, my first lathe) has a 3/4hp 220V 3-phase motor in it. It looks almost new, though I know that doesn't mean anything electrically. I have access to 1-phase 220v but would have to run some wiring to get it to the lathe. I have multiple 110v outlets right next to the lathe. So, I'm wondering what my best bet would be. Either get a 110v 3/4hp motor or a VFD to go 110v to 220v 3-phase. I know the VFD would give me variable speeds without moving belts that much, but for someone who never worked a lathe before would it be worth it? Which way would you go? Thanks.

 

[brt]

I'd go with a VFD. In fact, I intend to, as part of CNC-fying my PM 1236. I'm basically going to apply most of what I see on my CNC mill (a square column from Tom Spada @ IHCNC) to the lathe. That's also what Tom recommended when I asked him about it.

 

[Splat]

My vote is for the VFD also. You get variable speed and as a bonus 3 phase motors are dead simple, unlike single phase they have no capacitors to go bad and no starting switch. They are very reliable and typically run smoother. You should look for a sensorless vector drive like a Teco JNEV-101-H1 (115V in) or Teco N3-201-CS (230V in) or Teco JNEV-201-H1 (230V in) other brands are available and work fine but these are the ones I know and the price is reasonable. The JNEV 1hp drives run about $131 and the N3 $177 plus shipping online. Here is one source that I have used: http://dealerselectric.com/default.asp Check the FLA (Full Load Amps) rating of the motor, make sure the VFD you purchase is rated at least that high, biggger is fine.

Thank you guys. Clueless, thanks for that link! That company is about 20mins away from me! :thumbzup: The prices are roughly what I'd pay for a good 110v motor anyway so looks like a VFD it shall be! Thanks again.

 

[burnrider]

Has anyone else tried one of the many KB electronics VFD's.

I'm powering up the drill press at the moment with a 3 phase 1 hp motor. I didn't know a VFD provided a reverse mode as a bonus. Currently, I bench tested it, went ooh and ahh, then went back to work on installation. Took pics, and it looks like a great plug and play- mostly cuz' the 1-800 tech department is on the spot with information to get the right product for your specific use and motor type.

The VFD delivered from FLA to west coast was $143. I bought, cleaned and lube bearings on a 1 hp Century electric motor from Ebay for $55 delivered. I can't vouch for long time use, but I did find some happy users on the PM website.

I will post pictures, and parts added to finish up. There is a need for fan cooling unless you use a TENV motor for extended use. The total conversion was about $200. I started to post until the website was blipping like the old black and white TV.

Excellent project for those of us w/ limited circuit board experience, because you need none.
It's about a 6 X 6 X 6 unit due to the huge heat sink. The plastic box housing the SPDT switch for fwd/stop/rev and 5K pot for speed control is mounted on the press next to main power switch. (Using 110 volts for primary power.)

I'd recommend checking on other vendors mentioned here. The VFD is more quality and affordable than a few years ago.

 

[jumps4]

let me know what you decide on for extra cooling I have read that is an issue for lathes or mills on long runs at low settings. I'm thinking about a sheet metal enclosure around the motor with a 110v fan in the top, it will turn on any time the vfd is on.
steve

 

[PurpLev]

I had a 110v motor on my old lathe, and now am running a same HP 3-phase motor on my current lathe, motor for motor I must say that the 3 phase motor is smoother, quieter, and seems more robust than the 110 single phase motor by far. using a VDF I did not have to readapt any new motor to the current lathe + replacing the pullies (which was a PITA doing on my first lathe when I swapped the AC to DC motor). control wise the VFD is great, and can give you VS when needed as well. I am using a 110v IN to 3phase 220V out VFD (FM50-101) and am glad I went that route this time around - so much easier, and I got to use the original motor

 

[Splat]

Guys, I figured I'd post this in this thread...Maybe if I wasn't a lathe beginner I'd be able to realize the answers but alas, I'm just a beginner. So before I get a vfd for my Heavy 10 I better ask these questions, please.

When you're using a VFD on a manual lathe how do you know what speed you're at? What about belt/cone changes... do you leave it on the middle cone or still use different cones depending what material and process you're doing?

 

[burnrider]

let me know what you decide on for extra cooling I have read that is an issue for lathes or mills on long runs at low settings. I'm thinking about a sheet metal enclosure around the motor with a 110v fan in the top, it will turn on any time the vfd is on.
steve

I've got a fan ordered. KB electronics has a diagram of a 100 cfm fan mounted under the motor which appears to be open on both ends for cooling. They show no enclosure, but the motor is mounted vertically, so the fan underneath works perfect.

Purplev,
The VFD does the same for me. This motor happened to be the same frame as my Baldor 1 hp. It will accept the same 4 step pulley as well. A good solution if the VFD works as advertised. This is a real nice improvement for a drill press, lathe or the band saw. I still favor a DC tread mill power, but VFD technology is a great second choice.

Anyone using one of these for rpm reading?

 

[DMS]

Guys, I figured I'd post this in this thread...Maybe if I wasn't a lathe beginner I'd be able to realize the answers but alas, I'm just a beginner. So before I get a vfd for my Heavy 10 I better ask these questions, please.

When you're using a VFD on a manual lathe how do you know what speed you're at? What about belt/cone changes... do you leave it on the middle cone or still use different cones depending what material and process you're doing?

If it is the original motor (or at least the same speed as the original motor), then look at the faceplate value for the pulleys you are set at (say you the faceplate reads 1200 rpm), then look at your VFD. If it is set up to display Hz, then at 60 Hz the lathe will be running at about 1200rpm, at 40 Hz it will be 2/3 of that, or around 800rpm, 30Hz = 600rpm, 6hz = 120rpm.

You can also set up most VFDs to be direct reading (in rpm), but if you are switching pulleys, I'm not sure how that would work out...

If it's an older motor you should be careful running at really low frequency for long periods. I hear the motors can heat up.

 

[Hawkeye]

I have a laser tach, but I added a MachTach to my shared VFD installation. Take a look at: http://www.machtach.com/

It's sold as a kit and is very easy to assemble. I'm using the Hall Effect sensors with mine. A VFD with a tach display built into the control head is about as easy as it gets to set cutting speed.