What's the RPM?

tylandr · Post by **tylandr** » Thu Nov 12, 2009 2:02 pm

Hello All - new to the forum and very green. I have inherited an ER from my wife's grandfather who had installed a variable speed control quite a few years ago. I need to know what the rpm at the shaft is, but the motor's id plate is long gone. Also, I can't verify if the motore is original stock or not. Knowing him, it may very well not be.

Any suggestions?

Thanks in advance!

heathicus · Post by **heathicus** » Thu Nov 12, 2009 3:51 pm

Welcome to the group! Can you post some pictures of the motor, and the variable speed control? Does the speed control look like this?

[ATTACH]6534[/ATTACH]

If so, and assuming the motor is to original specs (3450 rpm), the speed changer has two range settings, high and low, depending on belt placement that gives a total range of 450 RPM to 6000 RPM. There were variations of the speed changer with indicators at 5 positions and 8 positions, but the total range is the same.

mickyd · Post by **mickyd** » Thu Nov 12, 2009 6:24 pm

heathicus wrote:Welcome to the group! Can you post some pictures of the motor, and the variable speed control? Does the speed control look like this?

[ATTACH]6534[/ATTACH]

If so, and assuming the motor is to original specs (3450 rpm), the speed changer has two range settings, high and low, depending on belt placement that gives a total range of 450 RPM to 6000 RPM. There were variations of the speed changer with indicators at 5 positions and 8 positions, but the total range is the same.

Heath - My motor is only 1725 RPM vs the 3450 you mention. See my nameplate

JPG · Post by **JPG** » Thu Nov 12, 2009 6:46 pm

Hey is right!!!! Mark 5/V are 3450, but typical Model 10 are 1725(2 pole/4 pole motors). I am not even sure the Model 10s all originally came With a motor!

mickyd · Post by **mickyd** » Thu Nov 12, 2009 7:01 pm

JPG40504 wrote:He's is right!!!! Mark 5/V are 3450, but typical Model 10 are 1725(2 pole/4 pole motors). I am not even sure the Model 10s all originally came With a motor!

Is there a way to tell the RPM of a motor, say by the wiring?

mickyd · Post by **mickyd** » Thu Nov 12, 2009 9:50 pm

tylandr wrote:Hello All - new to the forum and very green. I have inherited an ER from my wife's grandfather who had installed a variable speed control quite a few years ago. I need to know what the rpm at the shaft is, but the motor's id plate is long gone. Also, I can't verify if the motore is original stock or not. Knowing him, it may very well not be.

Any suggestions?

Thanks in advance!

If you don't mind spending $$, try this or wait for more forum responses. There may be a way to tell without a physical measurement.

heathicus · Post by **heathicus** » Thu Nov 12, 2009 10:04 pm

mickyd wrote:Heath - My motor is only 1725 RPM vs the 3450 you mention. See my nameplate

You are correct! It IS 1725, not 3450. See, I was, uhm... testing you! Yeah, that's the ticket. And you passed. Congratulations!

heathicus · Post by **heathicus** » Thu Nov 12, 2009 10:13 pm

JPG40504 wrote:Hey is right!!!! Mark 5/V are 3450, but typical Model 10 are 1725(2 pole/4 pole motors). I am not even sure the Model 10s all originally came With a motor!

I believe you are also correct. To the best of my knowledge, the motor was an optional accessory with the 10ER, but it was an option I would guess that most people purchased.

mickyd · Post by **mickyd** » Thu Nov 12, 2009 10:14 pm

heathicus wrote:I believe you are also correct. To the best of my knowledge, the motor was an optional accessory with the 10ER, but it was an option I would guess that most people purchased.

Except Fred Flintstone.....

heathicus · Post by **heathicus** » Thu Nov 12, 2009 10:15 pm

mickyd wrote:If you don't mind spending $$, try this or wait for more forum responses. There may be a way to tell without a physical measurement.

That measures surface speed, not RPM. Is there a way of converting the surface speed of a cylinder with a known diameter into RPMs? I'm sure there is, but there's a reason my degree is in English, not Math!