4 1/2" angle grinder wheel rpm?

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Taul Paul

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Sheffield, South Yorkshire
Does anyone know the actual general wheel RPM on a 4 1/2" angle grinder. I've seen 10 000 mentioned but
I find it hard to believe. Plan is to use one as a motor power source but I can't if it runs at that speed.

TP
 
10k is about right give or take a few hundred.
discs are rated to 12,500rpm.
the motor runs at considerable less at around 3000rpm for a 2 pole 50hz motor.
 
Ours run 11,000rpm on 60 cycle power. Yours will be a little slower because of the 50 cycle you use. The motors are like router motors so are geared down to get there.

Pete
 
In order to calculate this by formula, in addition to the diameter you would need to know what the Surface Feet per Minute is. In general saw blades have a 10,000 SFM which is the desirable speed to run a saw blade (This may be where you get your thought from).

From general information 4.5 inch diameter blades can have a rpm of 8000 but I must emphasise this is a guide and could range either side of this. Manufactures would have the information so give them a call.
 
The slowest grinders I've come across (variable speed Makita and Festool ones) start at 3,000 - 3,500rpm. I'm saying this in case the "300" above was missing a zero as that's really slow.
 
The slowest grinders I've come across (variable speed Makita and Festool ones) start at 3,000 - 3,500rpm. I'm saying this in case the "300" above was missing a zero as that's really slow.
Yes 300 is the target. I'm going to have to buy a 1400 rpm motor and pulley that down. 350 actually works as a 4 to 1 reduction so I'll go with that.
Thanks
 
10k is about right give or take a few hundred.
discs are rated to 12,500rpm.
the motor runs at considerable less at around 3000rpm for a 2 pole 50hz motor.
AFAIK, all corded angle grinders use a brushed motor, because to reach a speed of 10,000 RPM at the disc spindle requires a motor speed much higher; probably three times higher, which is not attainable by an induction motor.
 

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