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Grinder motor speed

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Forum topic by Lefley posted 02-28-2017 01:27 AM 451 views 0 times favorited 5 replies Add to Favorites Watch
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Lefley

22 posts in 345 days


02-28-2017 01:27 AM

I am making m own grinder buffingstation. Going to use cbn wheels. Can order any motor. My question is ive seen tormek set ups and 1750 rpm set ups. What would be a good hp and rpm for the motor as can pulley to any speed.


5 replies so far

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papadan

3584 posts in 3203 days


#1 posted 02-28-2017 02:24 AM

Faster is better for grinding, slower for buffing. Since you are building this yourself, use step pulleys and make it multi speed like a lathe or drill press. 1 hp 3400rpm

View mike02130's profile

mike02130

167 posts in 507 days


#2 posted 02-28-2017 03:32 AM

1750 is a good speed for tool sharpening. Most grinders are 3400. I don’t know much about CBN wheels but am hoping to learn from this thread.

-- Google first, search forums second, ask questions later.

View Kelly's profile

Kelly

1821 posts in 2779 days


#3 posted 02-28-2017 04:56 AM

This is mine. It runs an industrial, variable speed, reversible, one horse sewing machine motor. You can buy them, with the controller, for around two hundred. They are remarkable. I can run mine from zero to twenty-five hundred RPM. Today, I tried to bog it down pressing a HSS skew against the CBN wheel and I could not hear ANY bogging.

The DC motor replaced a 220, 1700 RPM motor and I would never go back.

Most my grinding is done at around five hundred RPM. If I’m not re-profiling a knife or chisel, or if I want to keep heat down, why would I go faster?

View HokieKen's profile

HokieKen

4510 posts in 973 days


#4 posted 02-28-2017 12:42 PM

Everyone has good points. I think the lack of direct advice though, is due to some missing information. Most importantly, what is the primary goal of your grinder? I would assume it’s probably for sharpening turning tools since your using CBN? What size wheels are you using, 6 or 8”? An 8” wheel will have a higher speed at the cut than a 6” with the same rotational speed.

I think that variable speed is the way to go in either case, if it’s within budget. A setup like Kelly’s is ideal but using a stepped pulley system like Papadan suggests is a more economical solution. I’ve never used CBN but I think most turners use them on slow speed grinders (1750 rpm).

-- Kenny, SW VA, Go Hokies!!!

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LeeMills

458 posts in 1136 days


#5 posted 02-28-2017 01:26 PM

This is my grinding station I made back in the early 80’s.
Motor is underneath on a hinged plate and the weight provides plenty of tightness for the belt.
Six inch wheels but plenty of room for eight inch.
L front white stone, R front Cratex for honing, R rear now has a green disc, L rear stropping charged with jewelers rogue.
Will run forward or reverse. Spindle will accept a 1/2” drill chuck for special needs (Top R).
Front is about 1750 back is about 1200.

-- We cannot solve our problems with the same thinking we used when we created them. Albert Einstein

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