Reversing motor direction on a grinder

[Paul Egan]

Hi: Can anyone advise me how to go about changing the direction of a motor driven spindle? It is a standard 1/2 HP 110 V grinder motor. I have removed the base plate which exposes wires coming from the motor housing to the switch (2 black) and two white wires going to some cylindrical electrical component.

Thanks & cheers, Paul

[Garrett in Victoria]

You can't do it electrically, because your 110VAC motor isn't reversible.

However, you can probably do it the way I did to use rubber honing wheels on one of mine.

Take the base off, rotate 90 degrees and re-install. Take the side covers off the wheels, rotate them into the new position and swap the tool rests. Takes about 30 minutes, but the effect is that the wheels rotate way from you.

Cheers, Garrett

[Bryan Cowing, Woodstock a]

you have to crack open the motor case and find the wires associated with the start winding. Just unsolder and switch the wires to reverse.

[Ken in Dartmouth]

Paul, grinders are made difficult to reverse for a very good reason. If you reverse the direction, the spindle threads, being of the "wrong" hand, may tend to become loose under use. The result of a wheel being thrown is not a pretty sight!

Ken

[J.P.Rap in Hamilton]

Now thats thinking outside the box...
...And a very simple solution that eliminates the concern of the nuts loosening.

Why mess with wireing when you can just make the back of the motor - the front?
Good thinkin Garrett!
J.P.

[Paul Egan]

Hi:
To all those who responded Thanks. As it turned out
what I ended up doing was rotating the motor 180 degrees on the base plate which in essence means the backside of the motor is now facing me, Garrett's standing behind the motor. This way I didn't have to fiddle with the winding, wires etc. It was recommended to reverse the direction for sharpening purposes.

cheers,

Paul

[Drew Peacock]

I would not recommend "sharpening" on a grinder.
They are only for grinding a rough shape.
You would be better off sharpening with a 1 inch belt sander like the Coulombe model that LV sells.
More control,less overheating and less steel worn away.
I only use my grinding wheels with new tools and as little as once per year there after.
When I nick something etc.
Oh yes, and the lawnmower blade. (VBG)

Drew

[Pete in Milton]

Quite a while ago, I've done exactly what Garrett suggested, rotating one end housing 180,the guards have to be relocated as well and on this side have mounted a hard felt wheel which I use with compound to finish the edge, the other side, rotating in the normal direction, is an 80 grit white wheel for shaping.
I plan to mount the grinder on a lazy susan type base and I will lock the base down for it's appropriate use.

[Ken from Ottawa]

[Ed in Leaside]

[Frank D.]

In that case you can also just take off the guard and turn the grinder around.

[Ed in Leaside]

Yahbut I happen to have 3 grinders. An old 6" CT model inherited from my father (good for lawn mower blades and rough metal work), an 8" used for shaping and lathe tools, and 6" Delta picked up on sale for $31 which has a soft and a hard felt on it. I figured flipping the armature on the base would be less trouble in the long run than reaching around the back to turn it on and off. Safer too and don't forget to swap the rotation decals in case someone else uses it. http://www.canadianwoodworking.com/forum/images/smilies/wink.gif