Primitive Archer

Main Discussion Area => Around the Campfire => Topic started by: Hawkdancer on June 10, 2019, 11:14:40 pm

Title: Any safe way to gear down a grinder?
Post by: Hawkdancer on June 10, 2019, 11:14:40 pm

Is there any safe, practical, (and inexpensive) way to gear down a standard grinder-polisher?  I am getting too lazy for manual sharpening, and my grinders are high speed.  A slow speed sharpening rig is 2 or 3 C notes or more! And the tax man cometh!
Hawkdancer

Title: Re: Any safe way to gear down a grinder?
Post by: Pat B on June 11, 2019, 05:35:31 am

Add a large pulley to the grinder motor and an off set frame with a small pulley on it driving the polisher.

Title: Re: Any safe way to gear down a grinder?
Post by: Woodely on June 11, 2019, 07:50:50 am

A electric  fan control may work or a dedicated speed control a cheap one could cost $60.  Controls are adjustable so you can vary your speed and find a happy medium no matter what you are grinding.

Title: Re: Any safe way to gear down a grinder?
Post by: Pat B on June 11, 2019, 08:42:12 am

Maybe a rheostat if the motor can take it. It might be a little cheaper.

Title: Re: Any safe way to gear down a grinder?
Post by: Woodely on June 11, 2019, 03:05:50 pm

You probably know more about electrical stuff than me. :)  ya; a rheostat  that could work.

Title: Re: Any safe way to gear down a grinder?
Post by: Pat B on June 11, 2019, 07:11:53 pm

Don't bet the ranch on my electrical knowledge.  (A)

Title: Re: Any safe way to gear down a grinder?
Post by: DC on June 11, 2019, 07:54:28 pm

The only trouble with a speed control is that the power seems to drop more than the speed. If you get the thing down to the speed you want it will dern near stop if you put a load on it. Using the belt reduction, on the other hand, increases the power so the speed will stay nice and constant. I notice this when I was making the arrow lathe that I posted a while ago. If I just used the sewing machine speed pedal I could almost stop it with thread tension. I made an idler shaft with a couple of pulleys and it works great. Nice and slow and it will break the thread if I want.

Title: Re: Any safe way to gear down a grinder?
Post by: Hawkdancer on June 11, 2019, 09:52:25 pm

I'm trying to visualize all this!  So I can put it together!  Thanks!
Hawkdancer

Title: Re: Any safe way to gear down a grinder?
Post by: Pappy on June 12, 2019, 04:38:52 am

Rheostat will work but is hard on the motor, pulley change is the way to go if you can work it out.  :)
 Pappy