the motor issue

[leeanneT]

hello people,

Gunsmithing is a hobby for me, bought the pre-used lathe last year. Now I figured out that something went wrong with the motor when I noticed the smell. Surely I brought it to the mechanic .Verdict: the motor is not worth of repairing. Who is familiar with the electric motors. I’ll be buying a new. This is unwanted expense for me, although I realize that good motor can serve during the years. So what to take? 3phase or single phase motor? What company?
thanks

[elk hunter]

Most areas don't have three phase power available and to convert single phase to three phase can be costly. Unless you have commercial three phase available at your site single phase is the easier way to go. Talk to your local electric motor repair shop and ask what you need and should buy.

[akajun]

More info is needed. What lathe, what size , hp, what phase is it now, additional electronics such as coolant pumps, apron controls, etc.
first get an NEMA book and a tape measure and figure out what motor class you have now. If your currently single phase but want to go three phase, you can get a vfd drive up to 3hp for about $200, less hp makes a less expensive vfd. Advantages of a vfd/ 3phase are smoother motor operation and fingertip speed control via the potentiometers. If you have apron controls you will have to do some work to keep those working.

[Der Gebirgsjager]

Sound advice from elk hunter. My equipment originated in Taiwan, and the lathe has a straight 220V motor that runs on regular 220 house current like your clothes dryer. The mill has a 3-phase motor, and uses a phase converter that tricks it into thinking that the regular 220 is 3-phase. You might contact one of the machinery companies that imports machinery from overseas and ask about motors, Grizzly for example; they might sell them as replacement parts and maybe you could get a straight 220V motor. You didn't say in your post what the motor is that went bad, so I'd go with something as close to the original as possible to avoid wiring issues.

[fg-machine]

im with akajun

3 phase motors are the only way to go on a lathe , the improved surface finish alone is worth is . the variable speed as an added bonus is icing on the cake with the vfd.
vfd's are relatively cheap for smaller motors and easy to install .

[rancher1913]

there should be a plate on the old motor with all the items needed to replace it, frame size, hp, phase, hz, voltage, fla. you will need to match this or be willing to do trial and error fitting. 3 phase is nice but you need to stick with what you had, most critical is spindle diameter and rpm so it does not screw up your lathe.

[leeanneT]

Most areas don't have three phase power available and to convert single phase to three phase can be costly. Unless you have commercial three phase available at your site single phase is the easier way to go. Talk to your local electric motor repair shop and ask what you need and should buy.
Yes I understand it, and I have a single phase. But I think that using VFD will give me additional control over the motors rmp.

This is my lathe Grizzly G4003G - 12" x 36" I was lucky to buy it in a good condition after the closure of one workshop.

After reading the net reviews, I decided on thos model https://www.mrosupply.com/motors/ac-motors/general-purpose-motors/26523_vm3546_baldor/
It is baldor, however i can not be 100% sure as for the tech specs. What is the quality of this manufacturer?
What VFD is to choose?

[akajun]

Absolutly go 3 phase with that machine. CHeck on youtube, there is a guy that converted one to 3phase with vfd that did a really good tutorial on it.
The motor you have is a foot mount, the one you listed is a face mount. Baldor makes very good motors, as does lesson. Also dont discount older/used American made motors. 3phase motors last forever, generally all you need to do on a small one is replace the bearings if even that.

[oldred]

Another vote for 3 phase, consider too that 3 phase motors are usually quite a bit cheaper than a comparable single phase of the same quality and power rating, that will at least somewhat off-set the additional cost of the VFD. The VFD controlled 3 phase motor opens up a whole new dimension of capabilities! Smooth variable speed in both forward and reverse, dynamic braking etc, you will not regret the extra money spent on the set-up.

[oldred]

Also you might want to check Surplus Center for that motor, if you don't see what you need you can call their tech help line and often they will find what you need. These guys have saved me a bunch of cash on electrics and hydraulics.

www.surpluscenter.com (http://www.surpluscenter.com)




Also for those who might be interested they are a great source for surplus QUALITY motors, gas engines, hydraulic components of almost every description, small tractor items from fittings to complete drive systems, etc. The cost discount on name brand electric motors, gas engines, etc is often substantial compared to normal dealers since these are limited supply surplus (but brand new) items.

[iraiam]

I have a Rotary Phase Converter and converted my lathe to 3 Phase with a VFD. If you don't want to add the cost of a phase converter, you can buy a VFD that will run on 220 single phase and put out 3 phase at a somewhat de-rated specification. I bought the motor I used from Surplus Center. I initially had a used ABB VFD installed but that one eventually failed, I replaced it with an Automation Direct VFD.

Converting my lathe to 3 phase with a VFD was the best thing I ever did to it, I get much better torque, the ability to turn the material at the exact required RPM gives great results. The ability to switch spindle direction by flipping a switch and the addition of dynamic braking were also very useful.

[DCM]

If you can afford it 3Ph and the proper freq. drive that is rated to have a 3Ph output from single phase input.

A 3Ph to 3Ph drive can be used on single phase but must be Heavily derated unless you want it to live a very short life, they are not normally rated for or warranted for this type of use.