Re: old sherline Y travel

At 07:11 19/10/00 +0000, you wrote:

>Printed out a paper copy of the flywheel, and it swings on the lathe.
>Still a little tricky getting the hextants cut out if I simply use the
>rotary table to "position" to the hextant (OK, pie shape) to be cut
>out. Mapping "C" (rotation around Z ?) to "Y" is a good solution, but I
>haven't figured that out except for "wrapping" "Y" around an "A" axis.
>I'm suppose if I were using 4-axis CAD/CAM and controller that this
>would be simpler? Still a good challenge to the old brain, 'tho.

I had a similar problem recently - engraving the markings/numerals on a 6"
diameter chapter ring for a clock, using a Taig CNC mill with only 5" or so
of Y travel. Ended up using an improvised rotary table, mounted with the
table horizontal, & its stepper substituted for the X axis stepper of the
mill. Worked very nicely. For some operations, I laid the whole toolpath
out in linear coordinates; for others (notably, the numerals, where I
didn't want to deal with the distortion caused by rotary X/linear Y moves)
I simply used the table to position the ring & then used linear X and Y
moves to cut the characters.

I've posted a set of JPG files under folder "Tony's files"
(http://www.egroups.com/files/CAD_CAM_EDM_DRO/Tony%27s+files/).

setup.jpg shows the "rotary table" - my CNC dividing head, made from a Taig
headstock, with a Taig faceplate to form the table, mounted with spindle
vertical by using one of the Sherline angle plates.

engraving.jpg shows engraving in progress. The rings and minute/hour marks
were engraved using the rotary axis for X; the numerals positioned using
rotary moves, but cut using linear moves.

clock1.jpg and clock2.jpg show the finished ring, after filling the
engraving with wax & silvering the brass.

All cutting was done using a carbide V-form D-bit, using AutoSketch to
generate DXF toolpaths for the rings/marks and SuperCam to drive the
mill. The numerals & lettering were done using SuperCam's in-built fonts.

Regards,
Tony