Thread: Direction of rotation

im sure you can jsut reverse the pos and neg wires to make it go the other way.

Originally Posted by Skew ChiDAMN!!

Does a bench-grinder run clockwise or anticlockwise?

It should turn towards you for grinding and away from you if you adept it for polishing.


Peter.

Originally Posted by Big Shed

This got me intrigued, I asked the question because I was fairly sure my lathe motor runs clockwise.

Well, went out to the shed, lathe-clockwise, bandsaw-clockwise, disk/belt sander-counter clockwise, dust extractor-counter clockwise.

So, take your pick!

It looks like you have to specify direction of rotation when buying an electric motor.

You generally do have to. As has bee said, easy to change.

Originally Posted by Sturdee

It should turn towards you for grinding and away from you if you adept it for polishing.


Peter.

Mount it the other way round. Tormeks go either way depending on which side you stand.

I've been toying with the idea of replacing the motor on my MC-900 with a twin-spindle job.

That way I could not only have the motor mounted on the opposite side of the headstock for better clearance, but I could also permanently add an AlOx wheel to the "free" spindle and have a grinding station built in to the lathe.

Just gotta work out whether I need to muck around with pulley-sizes to make it work...

Originally Posted by Skew ChiDAMN!!

I've been toying with the idea of replacing the motor on my MC-900 with a twin-spindle job.

That way I could not only have the motor mounted on the opposite side of the headstock for better clearance, but I could also permanently add an AlOx wheel to the "free" spindle and have a grinding station built in to the lathe.

Just gotta work out whether I need to muck around with pulley-sizes to make it work...

Just fit the grinding wheel to the "free side" and your pulleys on the other. Engine revs are the same no matter what.

PS. most grinders are 2880 revs but slower (1440) might be better any how.

Originally Posted by

Mount it the other way round. Tormeks go either way depending on which side you stand.

Not always possible , in the case of my bandsaw for instance I would finish up with the motor on the fron and having to re-engineer the drive wheels etc

Originally Posted by Big Shed

Not always possible , in the case of my bandsaw for instance I would finish up with the motor on the fron and having to re-engineer the drive wheels etc

That was in reference to Peters post about polishing.

Originally Posted by

Just fit the grinding wheel to the "free side" and your pulleys on the other. Engine revs are the same no matter what.

Exactly what I meant.

Originally Posted by

PS. most grinders are 2880 revs but slower (1440) might be better any how.

Slower would be way better for me, as it's my much-modified ol' beast that I'll be playing with.

At the moment it has a 4 pulley cluster on the end of the shaft (which belt-drives the reeves system on a lay shaft, then another belt to the headstock shaft) but it only uses the smallest dia pulley as the motor's too fast. I think it's around the 2800rpm mark.

By my calculations, the smallest pulley gives me around the 700-2500rpm range (which is still a tad too fast... I'd like a minimum of 300 or 500rpm) and the largest gives me around 2500-10000rpm.

Even for pens & lace bobbins, that's ridiculously, scarily fast! (Pen blanks hurt when they come off at those speeds... DAMHIKT. )

A 1440rpm motor would bring that all back into sensible, more usable speeds nicely, and probably give me my 300rpm bottom figure. Hmmm...

Originally Posted by weisyboy

im sure you can jsut reverse the pos and neg wires to make it go the other way.

pos and neg , I assume your shorthand to mean positive and negative , the motor is AC , ie that means alternating current and there is no positive and negative with alternating current , the average 3 pin plug has a neutral , earth and active connection , changing the active with the neutral will not reverse the direction of a single phase motor , DC which means direct current on the other hand does in fact have a positive and negative but the only dc you will usually come across in a home situation is a battery

Good day all,

Interesting to hear how many were interested in this, (and how many were not sure what the machines in their shed did, until they checked)

Also many thanks for the flood of assistance.

My summary again (for induction motors):

B/s CCW
Lathe CCW
Drill press CW
Dusty CCW

All viewed looking at the motor, from pulley end.

Changing over was as I remembered from my old lathe motor. 4 field windings terminated in a 4-square terminal array, with the 2 mains connections. Changing shunts from "vertical" to "horizontal" reversed rotation. Instructions were under the terminal lid.
Obviously, I don't recommend that anyone does this, without consulting a suitably qualified sparky.

I suspect that my old 550W motor is permanently CCW, as with only 2 field windings, reversing should not help??? Direction is probably induced by the arrangement of the capacitor circuit?

Anyway, b/s up and running, and a HUGE difference in performance. Far more than I would have expected with a change to 750W? Perhaps the winding configuration also provides more "grunt", particularly under load? Any opinions?

regards

Depends if you are talking Taiwanese pit ponies or Aussie Clydesdales as regards Horsepower.

Originally Posted by

Depends if you are talking Taiwanese pit ponies or Aussie Clydesdales as regards Horsepower.

Definitely the asian variety in both cases.