Re: Getting started - MaxNC comments

--- In CAD_CAM_EDM_DRO@y..., "stephen_stallings" <stevesng@n...>
wrote:

> The lead screws were connected to the motors
> with a rigid coupling and setscrews. This is
> bad enough by itself, but turns out to be
> required because there are NO bearings of
> any kind on the leadscrews. They are supported
> only by the feed nuts and the stepper motor
> shaft. This means that the motor bearings
> act as thrust bearings for the lead screw.
> While this may be sufficient on such a small
> machine, it did not inspire confidence.
>

Apart from anything else, this is not a smart idea for the simple
reason that end-float in most size 23 stepper motors is controlled by
a spring washer at the far end of the shaft. Press on the motor shaft
& it will deflect the spring, giving a couple of millimeters of end-
float. In other words, the motor bearings themselves are not capable
of controlling any end thrust in that direction - it is all down to
the spring washer. I hope they aren't still doing the same on their
current production.

Regards,
Tony