Re: Z axis

On Thursday 10 January 2002 09:33 pm, you wrote:
>
> Please point me in the direction of a set of plans to
> retrofit the z axis of my bridgeport for cnc operations.
>
I don't know of any available plans. There is one retrofit kit for the z-axis
from Microkinetics (www.microkinetics.com/convkit.htm) for some $1200 without
stepper motor. I know of two home built systems which use the quill. One is
Jon Elson's (www.artsci.wustl.edu/~jmelson/CNCconv.html) who is active on
this list. He had a page up with more pictures but I can't find it right off.
I also found pics of another conversion buried in another list. I know I
bookmarked these but can't now find them. I'll keep looking as I want to keep
this link. I did correspond with the builder of the second one. He was
talking of building the system commercially or producting drawings for sale.
I got the impression he did not now have either.

I am in the process of building one. I didn't have the $1200 laying around so
decided to substitute hours for dollars. Also my mill is a Supermax and I'm
not sure if it matches well enough to just clamp on a Z retrofit. It would be
far easier to buy one, but less expensive to build.

I have a QCad *.dxf layout drawing I'm working off of. I haven't completed
mine as yet so I know there are errors in the drawing. I'm even more sure
they are incomplete. :-( I could make these available to anyone on the
group. It would show you what I'm doing and give a starting point but IS NOT
a set of plans.

> I have seen pics of some nice setups using external ballscrew
> attachments.
>
I think this is best and is what I'm pursuing. I think Dan Mauch among others
are driving the knee rather than the quill. I fear the acme screw in the knee
will wear quickly if driven for cnc but maybe OK for 2 1/2 D. If a ball screw
is put in the knee the friction will no longer hold the knee up, it'll unwind
the screw and fall. All in all I opted for the quill.

> I am also looking for a good source of ballscrews for the x and y
> axis.
>
I purchased a retrofit kit from Rockford. They had one for my Supermax, had a
good price and good delivery. The Supermax was slightly different than the
Brodgeport. I have been happy with their product. I've purchased a ball screw
and anti-backlash nut for my Z axis from them since. If you have a Bridgeport
there are more options but I think Rockford is a good pick.

I hope this is of some use. :-)

--
Hugh Currin, PE
Mechanical Engineering Technology
Oregon Institute of Technology
voice: 541/885-1649
fax: 541/885-1855
e-mail: currinh@...