# Lathe running backwards



## ToddMR (Aug 11, 2010)

So just a couple weeks ago we found out the big old Montgomery Ward lathe my wife had been using is now running backwards.  Just to give you an idea this thing is old for the 30's.  The motor I can't even find online.  We have had our ups and downs with this thing too.  I am not even sure when it started turning the wrong way.  Anyhow, my buddy's dad has helped me out so much in the garage with stuff.  I was wondering if anyone has an easy method to try to reverse the motor direction.  I have no diagrams that I know of for the motor.  Worst case we end up using a different motor, but if I can simply flip some wires around I am all for that.  I know I am lacking some serious information here.  Just thought it a shot in the dark here.  Would the positive and negative wires being reversed cause that, or would that not matter?

Thanks in advance for the help.  I have not tried jumping the switch yet to see if it spins differently or not.  When I say backwards it spins up towards you instead of down and away from you, or counter clock wise instead of clock wise.


----------



## glycerine (Aug 11, 2010)

I would assume that swapping polarity would reverse the motor (like you already said reverse the positive and negative).  But, some motors have a start capacitor and that might not work.  Can you tell if the wires go directly to the motor or of there is any other circuitry in between?


----------



## Smitty37 (Aug 11, 2010)

*Switch Starter winding*

Usually if an AC motor is running backwards it is because the leads in the starter winding are reversed. There can be other causes. Any motor repair place should be able to fix it for you and it shouldn't cost much. I don't remember how to identify the starter winding but anyone working on motors will....such things have really not changed all that much since the 1930's.



The tag should tell you it it is an AC or DC motor...if it is a DC motor there would need to be some sort of a power supply to rectify the AC input. On a DC motor reversing the input leads will reverse the motor. I doubt that it is DC but it could be..


----------



## ToddMR (Aug 11, 2010)

It is the following:
Fairbanks Morse & CO. Chicago BY Wagner Electric Corp
AC Motor     TYPE  RA        FRAME 57X
MOD. C2973 K3323        1/4 HP
1725 RPM  1 PH   60 CYCLES
110 VOLTS  4.6 AMP     220 VOLTS 2.x AMP (hard to read)
WOUND   CONT.        RATING 40 degrees C
CODE G  SK Protector   2F33

 That is all the information I can make from the plate on the motor.  I think that answers some of the questions asked.


----------



## bad (Aug 11, 2010)

Why don't you just stand on the other side of the lathe


----------



## Gary Max (Aug 11, 2010)

Heck a 1/4 hp like that would be less than $20.00 on Ebay----unless you want that motor -------I would just replace it.


----------



## glen r (Aug 11, 2010)

More questions for you.  Are you using it on 110 or 220 volts?  Also did it ever run in the proper direction - since you've had it?


----------



## LarryDNJR (Aug 11, 2010)

bad said:


> Why don't you just stand on the other side of the lathe




I already suggested that, I told him we could turn the bench around.


----------



## ToddMR (Aug 11, 2010)

Well money is tight.  Also it is gravity tension, so being able to get a motor with the same frame is almost not possible.  Flipping it around would have the head stock on wrong end and the back 1/2 of the headstock doesn't have a cover so pulley plus belt would be exposed in front of turner.  It is running on 110 volts.  It did run the correct direction.  It has had the cover removed and cleaned out.  So I am thinking without us knowing it might have been wired back wrong to the cord.  Just trying to save some history.  I use my Jet all the time as for one it is MUCH quieter and has MT2 instead of MT1.  

Besides like most men out there, I want it to work the way its supposed to lol.

I really appreciate the help.  I think it might be one of those things where I will see if the wiring diagram is on the inside plate, if not I will try reversing the two wires and stand back why I flip the switch with a broom handle. lol


----------



## penmanship (Aug 11, 2010)

HA, that's the first thing I thought of too........(must be a Canadian thing:biggrin



bad said:


> Why don't you just stand on the other side of the lathe


----------



## KenV (Aug 11, 2010)

Two thought -- what changed???  It was running in one direction, and changed.  

I suspect the starting winding is having problems if you have not been working with the mortor wiring.   

For that size motor the amps suggest it would be rated closer to 1/3 or 1/2 HP today -- and you probably can adapt the PSI variable speed replacement motor to work for about $100 and have variable speed.  (2.5 amps at 220 is a nominal 1/2 hp)


----------



## hewunch (Aug 11, 2010)

If it was wired back wrong swap the black and white wires. (or just not the ground wire).


----------



## hilltopper46 (Aug 11, 2010)

Sometimes the wiring schematic for the direction is on the inside of the cover.  Have you taken it off again to see if you can see anything in there?


----------



## ToddMR (Aug 12, 2010)

hilltopper46 said:


> Sometimes the wiring schematic for the direction is on the inside of the cover.  Have you taken it off again to see if you can see anything in there?




Yeah that is what I was planning to do actually.  I am going to take a closer look at it this weekend actually.  Might even take some "inside motor" pictures to post up on here.


----------



## Parson (Aug 12, 2010)

bad said:


> Why don't you just stand on the other side of the lathe



Or just flip the plug over? :biggrin:


----------



## snyiper (Aug 12, 2010)

Dont laugh flipping the plug will reverse polarity on a older plug. It may have been unplugged one way and plugged in the other.


----------



## ToddMR (Aug 14, 2010)

Ok so I went out to the shop today and opened up the end of the motor.  I guess you call this the bell.  I have pictures below.  Two of the inside of the cover, and one of the inside of the motor.  Now I did try to reverse the positive and negative wires but the motor still spun in the opposite direction.  On the inside of the end cover there is a small metal arm and another small metal piece that holds it in place on the left side.  I am not sure what that is for or what it does.


















Here is a picture of the plate as well.


----------



## wee willie (Aug 14, 2010)

you could always use the tools upside down. I saw that once


----------



## jimm1 (Aug 14, 2010)

bad said:


> Why don't you just stand on the other side of the lathe


 
Turn your chisels upside down.:biggrin:


----------



## AceMrFixIt (Aug 14, 2010)

bad said:


> Why don't you just stand on the other side of the lathe


 
Yea, it may fit better on the other side of the room any way......Or is it a left hander?????


----------



## ToddMR (Aug 15, 2010)

Its all good guys.  Thanks for all the recommendations.  I am not about to start trying various wires etc, other than when I reversed the two.  I would if the motor told me what to do.  My friend's dad is more experienced than I am on this matter.  He actually wired the inside of my garage and was the one who rewired the motor to connect it to a switch.  He even said it was reversible at the time.  All was working fine, until a couple weeks ago.  I noticed it when trying to help my wife work on something and was micro meshing a piece and noticed the pads kicking up towards me.  I was trying to salvage the motor as it is the original that went with this 1930's lathe that was my grandfather's when he was a boy.  I was trying to make sure I wasn't missing something simple is all.  Thank you all very much for your input on this matter.  I think at this point it is something where I just need to shelf this motor, and use the one my friend's dad has for me sitting over at his house.


----------



## randyrls (Aug 15, 2010)

ToddMR said:


> I am not about to start trying various wires etc, other than when I reversed the two.




Todd;  An AC motor will turn in either direction.  They normally have a "starter winding" and a "centrifugal switch".  The starter winding gives the motor a kick in the preferred direction.  After a few revolutions the centrifugal switch disconnects the starter winding and the motor spins on it's own.

Try this.  Spin the motor in the preferred direction and then turn it on. If it keeps spinning in the correct direction, The starter winding is likely open.  

Late for church.....


----------



## dalemcginnis (Aug 15, 2010)

I posted your problem on another site and this was the answer I got.
 Posted: Sun Aug 15, 2010 6:24 am    Post subject:	  
"Dale, 
It's been about 40+ years since I've rewound and rebuilt electric motors and motor control circuits, so my 'memory' and CRS might affect my answer.

Since we're talking about a VERY OLD MOTOR, I'm not sure of the design of the commutator or slip rings on it. Most 'reversible' motors used a commutator and brushes to accomplish this 'reversible feature, while 'capacitive start' was used with 'slip rings' since this is a SINGLE PHASE motor. 

If it is of SPLIT COMMUTATOR design, then it is possible that either/both the brushes and commutator segments have worn to the point where either the brushes are so short they have tilted in their holders and contacted the wrong set of windings in the commutator OR the commutator has worn to the point where it is 'bridging' (shorting) between commutator segments. 

Normal procedure would be to replace the brushes and recut (undercut) the commutator gaps in between the segments (providing enough commutator material is left to do so). 

He would have to have the knowledge and skill to disassemble the motor to this point to do this. I'd think taking it to a specialist who deals with electric motors would be more appropriate since they could check out the stator and field windings to determine if the lacquer/varnish use for insulating the windings had 'broken down' allowing windings to short out internally. This is more likely to be the case, especially if the motor was run 'hot' under heavy load. 

Many 'earlier model' electric motors used permanent magnets in them too, and some used multiple magnet setups to determine speed and direction. CRS is really 'fogging' my memory here, especially since I can't see the motor itself. 

Motor direction and speed is controlled using the theory of MAGNETIC ATTRACTION & REPULSION using either permanent or electro-magnets to control the magnetic field. A commutator controls this by selecting a different set of windings to constantly change this. 

Whoo, now by brain is getting tired!  "


----------



## ToddMR (Aug 16, 2010)

All is good now.  My friend’s dad came over yesterday and modified a  motor he had.  We got it mounted and wired up.  Running correctly now.   Just shelfing the old motor.

Thanks for all the assistance on this!


----------

