industrial buffer help

[FigureLLC]

Having burned up our Harbor Freight 3/4hp buffer and soaking up time on our Craftsman 1/2hp buffer, it's time to ditch the mickey mouse buffers and anty up to the big boys. I'm not having a ton of luck finding what I think we need. I'm trying to keep the cost to $600 or so (buffer/motor only), otherwise I think the 2hp Baldor Caswell sells would be perfect!

Material polished: aluminum

RPM/wheel size: Based on a recommended surface speed range of 3600-7500fpm, we could go 1750RPM with 8-16" wheels or 3450RPM with 4-8" wheels. It seems to be difficult to find spiral and sisal wheels larger than 10", so it looks like the 3450 would be the option for us. It'd be nice to go with the larger wheels, though, due to increased clearance and reduced heat. Suggestions for large wheel suppliers? Also for the same HP rating, the slower RPM will have more torque, right? But the extra torque gets lost with the larger wheels required to keep the surface speed up, so it's really a wash, right?

Power: 2 or 3 hp, at 220V 1-phase or 3-phase.

Speed reduction: It's not immediately necessary, but it'd be nice... A belt drive buffer head with a pulley stack would be decent. Belt would give us some more flexibility with the power and quality of the motor, as well.

Drive: Direct or belt? Seems like the advantages of direct are compactness, low maintenance, and less exposed moving parts; advantages to belt are increased clearance at the housing, independent selection of motor, ability to run pulley stacks, maybe smoother/quieter operation?

Anything I'm missing or flat out wrong about?

If any of you pros could suggest a setup and manufacturer/vendor, I'd GREATLY appreciate it! Thanks! -Len

[baz]

mine are direct drives but if i had the choice i would go for belt drive for the reasons you mentioned plus you can upgrade to a stronger machine by changing motor size only.
larger wheels are available through most industrial polishing supplier
(sent you a pm about that)
10 inch wheels with a 1750 rpm buffer can get you a very good result with less material wasted then with a 3450 rpm 10 inch wheel .and at the same time running at 1750 with a 10 inch wheel makes it a safer speed and less chances of damaging some fragile parts.

[FigureLLC]

thanks for the info, baz! the more i research and think about it, the more i think belt drive is the way we should go. i'm going to call around to some local electric motor shops to see if they have any reasonably priced motors that would work for us. anyone have ideas for other sources of inexpensive decent motors?

[Rasper]

For motors: scrap yards, junk yards, eBay,(although the shipping can kill you),old window air conditioner units. 3/4 and up single phase motors are generally more expensive than old 3 phase motors. If you have 3 phase power by all means use it. I see 3 phase motors all the time in scrap yards for 25 dollars or less, sometimes a lot less.

Richard

[FigureLLC]

Originally Posted by Rasper

For motors: scrap yards, junk yards, eBay,(although the shipping can kill you),old window air conditioner units. 3/4 and up single phase motors are generally more expensive than old 3 phase motors. If you have 3 phase power by all means use it. I see 3 phase motors all the time in scrap yards for 25 dollars or less, sometimes a lot less.

Richard

i can scrounge up $25! i'll do some digging around! thanks!

[KENLUDE97]

Len


I just got this polishing machine from Sears. Its a 1.5hp and 8.0amps
http://www.sears.com/shc/s/p_10153_1...Bench+Grinders

I have not done too much with it yet, but so far it seams REALLY nice. And for only $140 not too bad. But it sure beats the pants off my old Robi 1/3hp bench grinder! (not a suprize there)

It is enough of a machine for me as i only polish for "friends".

I know that Eastwood offers a large varity in machines (more so than here) so it is at least worth a look.

Good luck.
Ken

[FigureLLC]

thanks for the heads up, but that craftsman is really 3/4hp. craftsman notoriously applies creative hp ratings to their products. Some things that help me get the full picture (usually have to tell by the current rating):

Power (in Watts) = Voltage x Current x efficiency (usually assume around .6)= 115V x 8A x 0.6 = 552W

conversion: 1hp = 746W

552W/746W = 0.74hp

general rule of thumb, you can get around 1hp/10A. if i see a motor that says it draws 15A, i ballpark it without actually working any numbers that it's a 1.5hp motor.

[GeneNewcomb]

Len, If your near Oklahoma PM me. I'm cleaning house and there are motors laying around.
Gene