Re: [CAD_CAM_EDM_DRO] Help converting Z axis of vertical mill

kiran_list_groups wrote:

>Hi,
>
>I have been lurking on this group for a while now reading up all I
>could on converting machines to CNC.
>
>I have taken the plunge and decided on EMC to convert my vertical
>mill. I have purchased ball screws (HIWIN) and fitted them to the X
>and Y slides.
>
>I cannot make up my mind on how I should tackle the Z axis of my
>mill. I have put together a web page to outline the problem
>
>http://www.geocities.com/kiran_list_groups/index.html?1037541612725
>
>
>

Yes, rack and pinion won't cut it! Keep the counterweight, that head
looks real heavy!
A ballscrew seems the only answer. Depending on what is in the column,
and whether there
is access between the dovetails, you might be able to put the screw in
the column, and a
link between the dovetails to the head. This probably is not how it is
built, though.
You could just mount a big ballscrew in the side of the column, as close
to the head as
possible, so the link between the ballnut and head is very short. You
can then rig a
plastic shield to keep the chips out of the way. I made a smaller
version of this
to move the quill on my Bridgeport. See http://pico-systems.com/CNCconv.html
for some general info on my retrofit, and there's a link there for
specific info on my
Z-axis conversion. It is not completely applicable, but may give you
some ideas
on screw mounting, making the link to the ballnut, etc.

Jon