Re: help--servos shaft stiff when unconnected

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

>
>
> bluecoast1 wrote:
>
> >Hi Jon,
> >
> >the shafts are 12mm (~1/2") and it's about all you could
> >comfortably do to get them to turn between two fingers.
> >They do spin freely at all--they stop immediately.
> >
> But with brushless motors, you
> need the proper amp/driver to spin them.

If they are brushless, the permanent magnets cause considerable
drag when powered down. A motor with a 1/2" shaft has a rather
high torque output (foot pounds, not ounce inches). If the drag
is 2-5% of that, it will feel like a lot when turning the shaft
by hand.

Do you know the rated torque of the motors? Can you measure the
drag (even roughly - wrap a string around the shaft, tie to
handle of bucket, put heavy stuff in bucket).

John Kasunich