Motor spinning wrong direction.

[Joe Hillmann]

I finally got my lathe running this weekend. Ibuilt a cabinet to mount lathe and a motor with a variable speed pulley on it (Push down and it opens up and slow downs, lift it up and it closes and speeds up, kind of like a snowmobile clutch.) The problem is when I turned it on the motor spins the wrong way. At the moment I just put a half twist in the belt but it gets hot and the belt wears very quick.

Is there any way to make the motor spin the other direction? The motor has 3 wires coming out of the coils. A blue and yellow come out close to each other and a black comes out a couple inches away and they go to what I am guessing is a start capacitor but it is a black square box with 6 connectors on it.

[Mikail Khan]

What kind of motor do you have? The direction of rotation of 3 phase motors is changed by interchanging any 2 of the 3 wires.

MK

[Joe Hillmann]

It is a 1 HP, 110 volt AC brushless motor. I don't know what it is originally from but it doesn't have any type of cover on it. It is just the laminations and the windings to mount to and all the wiring is exposed.

[Anthony Whitesell]

Which lathe do you have? My first thought is the motor is not the original. If you can mount it facing the other direction it will be rotating the other way. Any motors I have wanted to spin the other direction, I could not make happen. It may be possible, and I don't know how. You buy single phase motors with the direction specified. Check out surpluscenter.com. If you can't remount it. You may need to replace it.

[terry mccammon]

In general the direction of a single phase capacitor start motor is directed by the polarity of the capacitor. If you can be sure which wires are for the capacitor try reversing them. This does not constititue a professional opinion, just a suggestion.

Also in this world of google if you can find any kind of id on the motor google it and see what you get.

[Joe Hillmann]

I don't want to remount it because I built a cabinet for it that allows me to use the variable speed pulley on it and I would have to build a new cabinet to fit the motor facing the other direction. I also don't want to replace it because it has the variable speed pulley on it that fits on an unusual shaft.

[Ronald Blue]

It sounds like a clothes dryer motor with the laminations and open windings. It's doubtful that rotation can be reversed electrically. Someone else may know better then I. Good luck.

[Jim Rimmer]

Did it spin the right direction before you put the variable pulley on it?

[Dennis Ford]

Most likely the "black square box with 6 connectors on it" would allow reconnection for reverse and/or other speeds. Unfortunately without a diagram, it won't be easy to figure out which connections to use. Guessing wrong might let the magic smoke out of the motor; once the magic smoke gets out, you can't put it back in.

[Joe Hillmann]

Most likely the "black square box with 6 connectors on it" would allow reconnection for reverse and/or other speeds. Unfortunately without a diagram, it won't be easy to figure out which connections to use. Guessing wrong might let the magic smoke out of the motor; once the magic smoke gets out, you can't put it back in.


The black box has four connections on one end labeled "3" and "4" (there are 4 connections but they are connected in pairs so there are two 3's and two 4's.) The other end has two connections that are connected and labeled "black".

On the top the wires from the outlet go to the outside of the "3" and the "4" doesn't matter which wire goes to which. The blue wire from the motor goes to the "4", the yellow wire from the motor goes to the "3" (these two do matter otherwise all it will do is hum) and the black wire from the motor goes to "black". I can not bypass the box, if I do all it does is hum and get warm.

[Anthony Whitesell]

I'm sorry Terry. In an AC system, there is not polarity on the capacitor. Swapping the wires on the top of the capacitor will not accomplish anything. This is professional knowledge.

A single phase motor has two sets of windings, a three phase motor has (atleast) three. In order to have a repelling force to make the motor spin, there must phase difference between the set of windings. For three phase motors, the source is obvious. Less so for single phase. In a single phase motor the incoming power is split. Some directly to the motor, some through the capacitor. The power passing through the capacitor incurs a phase shift. Juela! Two phases.

I don't recommend trying this, but best case is that you move the capacitor from one coil to the other it runs backwards. Or slightly worse case, it has no effect. Worst case, the motor burns out.

I noticed the custom cabinet, but wanted your opinion on the possibility. If you can flip the motor, can't replace it, and can't reverse it. Then I suggest twisting the motor 10-20 degrees to keep the belt from rubbing on itself. This will add some extra stress to the bearings, but not much.

If you wanted to get real fancy, you could add a pair of pulley drive gears and another belt to reverse the direction.

[Anthony Whitesell]

Those six wires could also be for changing from 120V to 240V.

[Kevin W Johnson]

Might post some pictures to give everyone a better idea of what you are dealing with, someone may just recognise the motor in question.

[terry mccammon]

Anthony

You are so right. I have spent the last 24 hours trying to imagine what on earth I was thinking. I do think it is time to retire when I write a bunch of nonsense like that. Thank you for correcting and posting the correct answer.

The curse of on-line boards is that any fool can not only have an opinion, but express it. The virtue of this board is at least they are corrected, and very nicely if I may say so.

Thanks again,

[Jerome Hanby]

As often as not when I search for some topic here, I'll find some treatise from a danged fool only to realize it's something I had posted and forgotten about <g>


Anthony

You are so right. I have spent the last 24 hours trying to imagine what on earth I was thinking. I do think it is time to retire when I write a bunch of nonsense like that. Thank you for correcting and posting the correct answer.

The curse of on-line boards is that any fool can not only have an opinion, but express it. The virtue of this board is at least they are corrected, and very nicely if I may say so.

Thanks again,

[Ray Newman]

Might it be worth your time and effort to remove the motor from the cabinet, then take it to a motor or electrical shop???....

[Joe Hillmann]

Might it be worth your time and effort to remove the motor from the cabinet, then take it to a motor or electrical shop???....

That is probably what I will end up doing, I was hoping I could just swap a few wires and have it going in the other direction.