PDA

View Full Version : the motor on my lathe died



abunaitoo
06-30-2016, 07:13 PM
My old Craftsman lathe motor died.
Took it to the motor shop and it's to old.
No parts to be found.
He's looking to see what he has that would fit.

Has anyone bought a motor off of ebay????
I see two that might work.

Jedman
06-30-2016, 07:36 PM
I have a old Craftsman lathe and it was underpowered . I looked on Craigslist and found a seller with 2 , 1 HP motors at the same RPM and bought them both. The mounting base was only a inch wider and was able to mount one of the motors with only a small modification.
I was able to buy the motors for $ 30 each so a good deal I thought.
The original was only a 1/2 HP.

Jedman

country gent
06-30-2016, 07:36 PM
Also check Graingers, MSC and Mc MasterCarr

JSH
06-30-2016, 07:45 PM
You might look at the 3 phase that are converted to VFD. Sounds like a good time to upgrade to me.

bangerjim
06-30-2016, 09:00 PM
1725 RPM 120v single phase motors are everywhere! I would stick with 3/4 HP or so. Very common motor. Typically 1/2" shaft.

I converted all my tools to VFD's using 220v 1ø in and 220v 3ø out. Amazing control and power!!!!!

akajun
07-01-2016, 01:49 PM
Be careful not to put to big a motor on that lathe, I thin my old 12" craftsman was rated for 3/4 hp max.
That said now is the time to upgrade to a vfd and three phase, you will never look back

Mk42gunner
07-01-2016, 03:19 PM
You might check some appliance repair shops for an old fan motor. A lot of the older ones were ½ to 3/4 HP, 1750 RPM.

Robert

bangerjim
07-01-2016, 06:09 PM
Make sure the motor you get is a capacitor start. Normal fan motors are many times simple shaded pole induction motors with no start torque. Get a motor like this:

http://www.globalindustrial.com/c/motors/motors/belted-fan-blower-motors

LEADHOPPER
07-01-2016, 06:16 PM
Banger,

Are you able to use your tools as normal with the VFD. I have a old Logan lathe with the belts to change RPM. Would the VFD work with this set-up?

fg-machine
07-01-2016, 07:02 PM
If you do decide to go with a three phase motor and vfd .. a good upgrade .
don't buy a used older motor for use with it ... the varnish on the windings simply is not up to the task for long term use .

A modern vfd rated motor will give much better service As they have a much heavier coat of varnish designed for the extra heat a vfd controlled motor will generate .

but to contradict myself a bit ... most older American made quality motors hold up quite well with a vfd as long as you run the motor with in a reasonable range. . keep it in the 30-90 hertz range and they are usually happy .

Also with a step pulley lathe the vfd gives much better service when used with the step pulleys to fine tune the speeds for the work you are doing versus setting it on a midrange speed and using the vfd for your entire speed range

bangerjim
07-01-2016, 08:27 PM
I have not touched the flat leather belt on my SB lathe in 3 years. I keep in on the middle puly and let the VFD do all the control!

Yes, do watch the quality of motor. A VFD is very hard on the windings and cheap motors will burn out easily...they are made for 60 HZ and when you start going from 30-90 or so, it can cause problems long term. Spend a little more and get a quality motor that is VFD rated. All are NOT!!!!!!! Beware cheap Chicom motors on evilbay or Amazon.

44man
07-02-2016, 09:43 AM
Had my motor on my Smithy fail right away. I have the Granite. I took it apart and found the brush springs shot. I called and got new ones free but in the meantime I went through my scrap spring can and found two to fit. It has not failed in years since I fixed it.
If winding's short and burn, nothing you can do. I saved a few motors with a spray paint made for insulation. Soak the winding's with it and let dry. Some kind of lacquer.
I do funny stuff with cheap fans. I soak motors with soap like Simple Green and hose out. let dry and oil the felt for bushings.
Many motors have a centrifugal switch and contacts need cleaned but capacitor starts can have the cap go bad. It will not give the boost needed.

bangerjim
07-02-2016, 10:27 AM
OP - Most lathe motors are capacitor start/induction run motors and not universal AC/DC brush-type motors. Watch that when replacing yours. Every lathe I have ever had in 45 years used 3/4 or higher HP 1,725 cap start motors. The teeny little Sherline I have uses a sewing machine universal AC/DC brush-type motor. Some of the new solid state controlled smaller lathes & mills use 90VDC brush-type motors and have almost the same speed control and torque performance as a VFD. I have one of those smaller bench mills for small work and they perform GREAT! My big mill uses a 2HP VFD.

Good luck on your motor quest in HI! Around here I have several industrial controls salvage stores that are a good source for motors and controls.

banger

When you finally make the switch to VFD's and 3ø motors, all that capacitor and inertia starting switch failure garbage goes away! That is why industry uses 3ø motors.......hardly any maintenance/failure. I like that.

abunaitoo
07-02-2016, 11:01 PM
I almost sure it's a A/C motor.
It has a flat cap in the base.

Frank46
07-02-2016, 11:30 PM
The red varnish used for motor windings is called Glyptal my spelling may not be correct. Frank

bangerjim
07-02-2016, 11:59 PM
I almost sure it's a A/C motor.
It has a flat cap in the base.

If it uses a capacitor, it is an AC motor. It will also have the inertia start switching as described above. That is what turns off the starter windings as the motor gains it's speed.

abunaitoo
07-08-2016, 09:49 PM
I found one for a reasonable shipping price on ebay.
Couldn't find anything on this rock.
Looks to be a newer model.
Label reads that it is reversible.
If it fits, I have a barrel switch I'll have put on it.

bangerjim
07-08-2016, 10:52 PM
Just follow the wiring diagram to reverse. I had a barrel switch on several lathes B4 I went to VFD.



Glad you found a solution!!!!!!!!!! Many options out there.

banger

woodsxdragon
07-09-2016, 11:20 AM
My old south bend came with a ge washing machine motor. I put a vfd with a 3 phase on it last spring. I bought the drive and motor as a combo unit from eBay. It wasn't too hard to wire up and make a control panel for.

W.R.Buchanan
07-10-2016, 03:02 PM
I have a A/C Tech VFD on my new mill and I have it setup to run off the Bridgeport Switch so the machine runs just like it would on 3 phase. I have the control setup to go from 0-60 Hz. in 1 second. The start is smooth, and I can reverse for tapping with the switch just like you normally would.

http://www.actechdrives.com/AC-Tech-Drives.htm

I could setup 7 different frequencies/speeds (20-72HZ) with that control, but chose to set it up as a one speed and just continue to use the Reeves Drive on the machine like you normally would.

My old Step Head Bridgeport uses a 90V DC motor and a Minarik DC Drive that runs off 110VAC.

https://www.minarikdrives.com/

It has 0-100% Varispeed in both directions, in addition to the steps on the pulleys and the back gear. In low low I have actually twisted off a 1" pipe tap in a piece of SS with this mill.

It also has the capability of running between limit switches which allows me to tap holes at a very high rate. I can do 20 per minute on most anything that can be loaded that fast. This mill is a very useful piece of equipment, currently setup as a precision Chop Saw with a Right Angle Head and being used for cutting .375 Guide Rods for my Hand Presses. If I need to tap lots of holes this is the machine as it is much faster and far more versatile than a Tapping Head. I can tap any size tap that I can get in a chuck or collet or endmill holder,,, It has that much power!

These machines are in my Shop that I make my living with. I don't know if I would go to the trouble or expense of setting up a VFD for a Atlas or other Hobby type machine unless it was going to get used ALOT. That said, if you could find a brush type motor that was big enough you could control it with a Variac or other large Potentiometer.

I'd shop around a lot before I dove into this project. Plenty of ways to spend a bunch of money and get screwed. Outfits also don't like returns on Electronic goods.

Randy

Char-Gar
07-10-2016, 05:14 PM
There is no such things as no parts, just people who don't know how to repair electric motors the old way. My Logan came with a cast iron motor that was about 100 years old. I took it to a local shop where the same old gent had been working at the same bench for 45 years repairing motors. He installed new bushings and a new cord and it ran like new. The shop wanted the motor and offered to trade me a brand new one for it. I declined and it is still on the lathe.

bangerjim
07-10-2016, 05:45 PM
I have several of those very old CI frame motors in my antique tool collection. They never wear out. 2 of them actually use brushes & commutator but are AC only motors. That IS old!

I figure they are at lease 100 years old and still run great. It is amazing how big a 1/2HP motor was in those days. Compaired to all these Chi-Com cheeeeeep imports today.

abunaitoo
07-11-2016, 03:47 PM
Being on this rock, we're at the mercy at what's here.
Old timers are retired or gone.
Any web page that would show how to test the motor????
I'm thinking the cap is dead. It's a flat cap.
I've seen them replaced with the round ones.
I'd like to test the winding.

KCSO
07-11-2016, 05:41 PM
I have never felt the need for a VFD on my od Atlas as it has 16 speeds and is easily changed and has torque at low rpm that I found missing on the vfd units I tried. I still have the OLD Craftsman 1/2 horse motor but it is the old one with the copper windings and is way heavier than the modern motors, once it's going it takes a lot to stop it.

abunaitoo
07-16-2016, 02:42 AM
Working on installing the new/old motor.
It's 1/2 hp, 1725rpm, newer Craftsman model. Looks like it came off some kind of wood machine. Saw dust all over.
Cleaned it off and it works great.
Have to modify the mount a little. Waiting for the paint to dry.
Replaced the power switch. I'm going to try it before wire the drum switch on it.
Hopefully all works good and I can get the lathe back in service.
Don't really use it much, but....
"it's better to have a lathe, and not need it, than to need a lathe, and not have it."

rbertalotto
07-16-2016, 07:24 AM
Somewhere on my web site is an article I wrote on converting my lathe to DC drive. Best thing I ever did!

www.rvbprecision.com

abunaitoo
07-19-2016, 04:51 AM
Lathe back in service.
Need to pick up some wire for the drum switch.
Running great. Very smooth.

comdiver
07-26-2016, 02:19 PM
I have seen a couple of small lathes converted to DC motors with a AC power supply that offers variable speed. There are a number of internet pages about taking a motor and controller from a treadmill putting it on a lathe. Free, garbage picked treadmill.

Hinnerk
07-26-2016, 02:56 PM
When I was a kid (decades ago) I used a scrounged washing machine motor to get my dad's old Craftsman lathe running.

cheese1566
07-26-2016, 04:27 PM
I have seen a couple of small lathes converted to DC motors with a AC power supply that offers variable speed. There are a number of internet pages about taking a motor and controller from a treadmill putting it on a lathe. Free, garbage picked treadmill.

I picked up two treadmills the last few weeks. I am planning one for my little Craftsman baby lathe and the other for my drill press. I found a cheap digital LED 12v tachometer on eBay for $10 to indicate speeds.