Re: [CAD_CAM_EDM_DRO] SeriesII Quill Zaxis CNC addon ideas: Like Jon E's?

Lee Studley wrote:

>I was wondering if, in the future, it would be feasible to add
>a ballscrew mechanism to move the quill of my older seriesII model;
>where the knee is the Z axis. The quill at one time had
>the air-driven-spindle-wizard-rotary-depth-stop-thingy( technical
>term ) which I removed.
>The mill has a larger 4.25 diameter quill that is a little 'sticky'
>to move. A previous owner put way lube thru the quill I think at
>some point. It has has gotten easier over time as it works out.
>
>

I had massive amounts of crud jammed up between the quill and housing.
I occasionally
clean the quill and wipe grease onto it, and then run it up and down a
few times. If the
quill fit is still real tight, grease would not be a good idea.

>I remember seeing a picture of Jon's setup where a 'clamp' is
>attached at the end of the quill with a ballscrew to move it.
>

No, I did not put a clamp on the end of the spindle. I drive it through
the hole provided
for the depth stop ring, which is about in the middle of the quill.

> I also
>saw on Ebay a mill just like mine, but they had some weird ballscrew
>setup on top of the head that appeared to work straight down the
>drawbar entry hole.
>

This is the full 3-axis CNC head. It doesn't connect to the spindle,
but to the quill. In fact,
the top of the quill has the ballscrew thread ground right into it. The
ballnut revolves around
the quill.

> My quill doesn't have the drawbar hole that goes
>all the way through to the tool holder. Its a quickchange type 40
>taper. Options I'm guessing at are:
>1) Using the depth bar that moves in parallel to the quill ( sturdy
>enough? Offset force issues? ).
>

I don't think you have to worry about the offset issue. The quill fit
is REALLY good, and the
quill is not going to tilt. I don't know whether the setup is more or
less rigid than the 1J
head. I do get a small bit of backlash due to a rocking of the link I
made between the
quill and ballnut. If I ever have to tear it down, I might try using
some spotting dye
and see if I can get better contact between the link and the quill.

>2) A clamp on the quill and several ballscrews to drive it up/down.
>3) Something through the center of the quill. Probably disassembly
>and modification needed to the quill.
>

Well, the top of the quill comes up pretty close to the back gear
mechanism and direct drive
clutch, so there isn't much room above the quill. I think you are
pretty much stuck with an
offset scheme, unless you get a BOSS CNC head. If you find someone
un-CNC'ing a
BOSS machine, swap heads with him, and you'll both be happy.

>4) Just use the Knee and shut up :-) most likely what will occur.
>
>

If your knee ways are in good shape, that should be fine. Make sure the
vertical ways are
getting plenty of lube, and make sure you have a way guard to keep chips
out of there.
If the knee ways get worn, the table rocks in the Y direction when the
knee reverses
direction, and that can be a pain.

Jon