Belt Grinder Belt RPM

If I was stuck with one speed and it was 2357 SFM that would be about right. Faster than that is trouble when finishing.
 
Did the math on mine w/a 3/4 HP 1750 RPM and 2" direct drive wheel and it works out top 916.27 FPM. Slow, yes but as a beginner it works for me! Lots of torque, I never bog it down! I have a 2 HP motor on the shelf but need to drop a 220 line into my garage. I'll go to step pulleys at that time.
 
Mike_Torello said:
if it's relevant to the topic, my motor is 1,1kW - 3phase - 380V
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That's useful Mike. 1.1 kW is 1 1/2 HP and being 3-phase means you "only" need to add a VFD for variable speed.

With the VFD, you could run up to 60 Hz instead of 50 Hz and get a 20% increase in maximum speed without exceeding the motor's design limits.

Roughly half the world uses 60 Hz and the rest uses 50 Hz. Anyone making motors designs for the worst case of 3600 RPM (a 2-pole motor at 60 Hz will run at 3600 RPM when unloaded). Usually 4-pole motors use exactly the same rotating components as 2-pole motors, so a 4-pole can usually be run to 120 Hz without problems.
 
I was wrong, it was missunderstanding about motors...

Motor that I have IS 1,1kW, but 220V not 3 phase 380V... about those 2-pole - 4-pole, I don't know... here is what's on motor ID plate, so if you can figure something out of that...

motor type: ESKA 90 S2
rpm 2860/min
220V - 9,2A
50Hz
IP 44
and this is what I can't identify right because paint.. I guess it says
"LKLE"

that "S2" in the motor type could be "pole" I guess, because I saw same make, only smaller 0,25kW - ESKA 90 S4

P.S. it was water pump motor before...
 
While A 50Hz motor will run fine on 60Hz, it will run 20% faster and have a an equivalent loss of torque.
 
Often, but not always Stacy.

Quite a few IEC motors stick with the rated current/torque and produce about 20% more power on 60 Hz.

The only way to find out is usually to check the rating plate or the manufacturers website.

With freely-programmable drives, it can often pay to carefully check the motor rated frequency and current values for both 50 hz and 60 Hz to see which will give the best curve for the application. I'd guess the options may be more limited on jumper-programmable drives.
 
old thread but I though I'd share this.

How does a customer convert RPM speed into SFPM?
A simple calculation is .262 x diameter of wheel in inches x RPM = SFPM.
 
Thanks! Old post, but making 2x72 grinder so this is very useful. Have several motors laying around but wasn't sure which one was best to use. Will probably do 3450 with step pulley. Also, OP wrote...

Well, the VFD is on a 15amp 110 circut and when I want to Hog and press a little harder, it pops the breaker immediatly so maybe going to a 4" drive pulley may help with this, thanks for the explanation.
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IMO a 1 1/2 hp 110 motor really needs a 20 amp circuit. 15 amp is running too close to the edge even with no load. Just in case anyone reading this doesn't know, you cannot simply change the circuit breaker. It is usually maxed out for wire size. Would risk burning shop down if mismatched. (15 amp=#14 wire. 20 amp=#12 wire).

Just found this site, so thanks again for sharing this stuff!
 
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