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Gadgets, Gizmos, and Dohickeys => Cutting, Grinding, Polishing => Topic started by: MOR4LES on March 13, 2019, 09:39:31 AM

Title: SLAB SAW MOTOR
Post by: MOR4LES on March 13, 2019, 09:39:31 AM

I'm in the process of making a slab saw with either an 18 or 20" blade.  I know the rated RPM for an 18" blade is anywhere from 600-1200, and a 20" is 550-1100, but here's where I get lost...I have about a dozen motors in a variety of sizes, but I don't understand enough about them to know which motor would work best for my needs...ARGHHH!!   ]These are my options...

Rockwell      1/2 hp, 1725 rpm, 115 v, 9.8 amps
Leeson        1/3 hp, 1725/1425 rpm, 208/230 v,  1.5/2 FLA (amps?)
Master        1/2 hp, 3450 rpm, 115/230 v, 7 amps
Baldor         1/2 hp, 3450 rpm, 115/230 v
Century       1/2 hp, 1725 rpm, 115/230 v, 7 amps
B Bearing     1 1/4 hp, 3450 rpm, 115 v, 14 amps
Craftsman    1 hp, 3450 rpm, 115 v, 14.0 amps
A. O. Smith  3/4 hp, 1725 rpm, 230 v, 5.1 amps
A. O. Smith  3/4 hp, 1725 rpm, 115/230 v, 10.5/5.2 amps
Dayton        1/3 hp, 1725 rpm, 115 v, 5.9 amps
G. E.           1/2 hp 1725 rpm, 110/220 v
                  1/2 hp, 860 rpm, 110 v
Any advice as to which motor would be the one to use would be GREATLY APPRECIATED!!
Thanx!

Title: Re: SLAB SAW MOTOR
Post by: catmandewe on March 13, 2019, 11:36:16 AM

3/4 or 1 hp motor with 1725 rpm, capacitor start is a big plus, check the service factor anything above 1.0 is good the higher the better, have to take into account the rotation, some rotations are reversible by switching the red and black wire inside the wiring box, 220 v is cheaper and preferable but 110 v is doable if you have a good enough breaker to carry it.

Tony

Title: Re: SLAB SAW MOTOR
Post by: Jhon P on March 13, 2019, 08:19:12 PM

You can calculate your rpm with the pulleys.
I would go with a step pulley so you can change the speed.

Title: Re: SLAB SAW MOTOR
Post by: Downwindtracker2 on March 13, 2019, 10:49:54 PM

I don't think the saw blade speed needs to be adjusted, just the feed rate.

Title: Re: SLAB SAW MOTOR
Post by: MOR4LES on March 15, 2019, 10:12:06 AM

I know that pulley sizes determine rpms...what I was hoping to find out is which motor on the list would give me the torque I would need.

Title: Re: SLAB SAW MOTOR
Post by: Slabbercabber on March 15, 2019, 05:30:09 PM

3/4 hp will work for almost all situations, but I have a 20" sintered blade that is very thick and I push it pretty hard.  If maxing it out I run a 1 hp motor pretty good.  I don't think 3/4HP would do it.  Then again, I use pneumatic drive at maximum efficient force.  Fixed speeds probably will not cause a problem for 3/4 hp.

Title: Re: SLAB SAW MOTOR
Post by: lapidaryrough on March 16, 2019, 06:51:37 PM

Any farm duty  rated motor is best. their sealed bearings an fan cooled.
 Though today's motors need up graded to the next hp needs.

  I have two 24" saws. and 18"  all now have farm Duty 1 Hp. motors.

  As for your needs for the blade you use. consider time per inch of cut, an what is best speed for blade an cut of material. are you cutting full radius of blade, Max cut.

 Most saws have 1750 RPM motor speed.  Down the road around Lebanon Oregon. friend uses 3400 motors on large saws only,  the local MK-dealers don't mind.
if it speed you need  switch motor speed.

  Jack

 

Title: Re: SLAB SAW MOTOR
Post by: MOR4LES on March 18, 2019, 10:00:03 AM

What is a farm duty motor?

Title: Re: SLAB SAW MOTOR
Post by: lapidaryrough on March 18, 2019, 06:39:50 PM

Quote from: MOR4LES on March 18, 2019, 10:00:03 AM

What is a farm duty motor?

http://www.rselectricmotors.com/motors2.asp?Index1=Agriculture/Farm+Duty+Motors&gclid=Cj0KCQjwg73kBRDVARIsAF-kEH_uhz3GqG22XdxD-gozeFcdeq5RbAd3ENNWypVJtD8EB6j-2l7CWsYaAqlKEALw_wcB

Title: Re: SLAB SAW MOTOR
Post by: Slabbercabber on March 19, 2019, 06:18:18 AM

Farm duty is sealed fan cooled and oversized fins for use in outdoor dusty and flammable environments.  Perfect for grain bins on farms.  Serious overkill for indoor slab saws.