Re: stepper motor inertia

Bob,
You're right, there are many sources of friction.
Maybe the motor could be loosened and a torque arm placed on it to
counter movement. The force at the end of the arm could be used to
calculate the torque the motor needs to overcome friction.
The friction should be the same at any speed, so just drive the motor
at some speed and measure the torque. This would be useful info for
my calculations.
Some people might find that the friction would vary along the stage
travel. This could be useful in working in the ways.

The couplings on my Taig are steel, aluminum would be a better choice
from the standpoint of inertia.

regards-
Elliot

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Bob Muse" <mtebob1@...>
wrote:

>
> Hi Elliot
>
> Very nice analysis. One thing you might want to consider is that

the motor coupling is often made from aluminum. Also there will be a
large difference in friction between a ball screw and 60 deg V thread.

>
> Bob
>
>
> [Non-text portions of this message have been removed]
>