How can I measure the speed of my lathe without using an expensive imported
tool ? I don't think I can trust whatever's marked on the motor, as it is
10-12 years old and probably not the original thing. For reference, I
borrowed a used Rockwell-Beaver model 3400.

Thanx to any and all who reply.

Pete

Hi Fleau

Is there not a plate on your motor ?
If there is, clean it up, and look, it should tell you the RPM
Then it is simple multiplying or dividing to get the speeds.

Have fun and take care
Leo Van Der Loo

"Dr Fleau" wrote: (clip) I don't think I can trust whatever's marked on
10-12 years old and probably not the original thing. (clip)
^^^^^^^^^^^^^^^^^^
The speed of the motor is not going to change with age. Do you mean you
don't think it's the original motor, or that it is not the original
nameplate? It's extremely unlikely that someone has replaced the nameplate
on a motor with one showing the wrong RPM.

To do a measurement without a tachometer or other instruments, here is how I
would proceed: Mount a faceplate with a piece of scrap wood on the spindle.
Drive in a few nails, evenly spaced. Hold a card against the nails, and
tape record the sound. Take the tape recording over to your piano (you do
have a piano, don't you?) and match the pitch. It's all arithmetic from
there. I"m sort of half-kidding, but the method WOULD work.

"Leo Lichtman" wrote in message
news

"Dr Fleau" wrote: (clip) I don't think I can trust whatever's marked on
10-12 years old and probably not the original thing. (clip)
^^^^^^^^^^^^^^^^^^
The speed of the motor is not going to change with age. Do you mean you
don't think it's the original motor, or that it is not the original
nameplate? It's extremely unlikely that someone has replaced the
nameplate on a motor with one showing the wrong RPM.

To do a measurement without a tachometer or other instruments, here is how
I would proceed: Mount a faceplate with a piece of scrap wood on the
spindle. Drive in a few nails, evenly spaced. Hold a card against the
nails, and tape record the sound. Take the tape recording over to your
piano (you do have a piano, don't you?) and match the pitch. It's all
arithmetic from there. I"m sort of half-kidding, but the method WOULD
work.


Count the number of windings.

http://www.oddparts.com/acsi/motortut.htm

counting poles is good. another approach is to gear it way down - say
100 to 1 or 500 to 1 and then count revolutions for a minute, and then
multiply.

or just borrow an RPM meter from someone - they are ubiquitous.

On Fri, 17 Feb 2006 19:40:20 GMT, "Dr Fleau"
wrote:

How can I measure the speed of my lathe without using an expensive imported
tool ? I don't think I can trust whatever's marked on the motor, as it is
10-12 years old and probably not the original thing. For reference, I
borrowed a used Rockwell-Beaver model 3400.

Thanx to any and all who reply.

Pete

Bill

www.wbnoble.com

to contact me, do not reply to this message,
instead correct this address and use it

will iam_ b_ No ble at msn daught com
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