Re: [CAD_CAM_EDM_DRO] Stuck between a rock and a hard place: Z axis conversion with manual control

photoshop4eva wrote:

>Hello All,
>
>I'm retrofitting a Bridgeport Series 1 clone (a machinist's dynapower, to be exact) and am
>stuck on the z axis motion. The mill is in my father-in-law's shop, and while he's very
>interested in CNC control, he desperately wants to keep full manual control of his mill as
>well.
>
>

All I can tell you is that you need to make this mechanism VERY stiff, or
you will have horrible backlash due to flexing of the linkage between
ballnut and quill. I have seen several add-on schemes that plain didn't
work, with .010" to .030" backlash! That makes it useless except for
drilling holes. You need to keep the ballscrew as close to the quill as
possible. More than 2-3" separation will be useless. And, the link
needs to be stiff in the quill travel axis. Depending on the construction
of the adjustable stop, it may be possible to make or modify the stop
to accept a bolt that couples it to the ballnut.

Jon