On Oct 28, 2:15*pm, John Weeks wrote:
I've been trying to construct and indexing disk for my lathe. It has
24 hole indexing built in, but I want 48 and 96 as well. I'm trying to
come up with the best way to lay out the holes and dril them on the
drill press. My first thought was to use a pin guide, something like
cutting box joints on a table saw, to avoid having to position the
drill bit by eye.

I carefully drilled the first two 3/16th inch holes the correct
distance apart, carefully positioning the disk with a 1/16th inch
drill in the chuck, clamping thedisk down, then switching to a 3/16th
inch bit and drilling the hole. The center of the disk is revolving on
a pin at the radius I wanted. Then, with the bit in the 2nd hole, I
pressed a pin through a guide block *into the first hole and clamped
the guide block in place.

I should be able to remove the pin, rotate the second hole under under
the guide, position it with the pin, drill the third hole, etc.

It's not working. When I get around the diameter I have lost or gained
a third to a half the distance between the holes. The drill press
table is locked down tight, the pin is a good tight fit. But there is
slop creeping in someplace.

This time I'm going to print a compass template with 48 radii and
position the bit by eye. The individual holes may be off slightly but
they should each be within a certain degree of error from the right
point.

Anybody have any better way of doing this?

I thought about using the index on the lathe, drilling the 24 holes,
then slipping the disk half the distance and going around again. But
I'd have to build a positioning jig for lathe drilling first.

JW.

Hello John,

I didn't see this message until today. Now, I'm sure that I need to
get another way to read the newsgroup.

In relation to your question, I've made a number of indexing wheels
over the years. The easiest way is to use Woodturner PRO or one of the
other segmenting projects. Select a ring diameter that will print onto
an 8-1/2 x 11 inch page. Set the center diameter to the diameter of
your lathe spindle; i.e. 1", 1-1/4", etc. Then set the number of
segments to 96. Drill a hole for the center point i\of a size to slip
over your spindle. Print out the drawing, cut out the center hole for
the spindle, and glue it to your indexing disk using the lathe
spindle to center the drawing on the plate when gluing.

Now, turn the disk round to match the outside of your drawing that has
been glued to it. Then take the disk to the bandsaw and make cuts on
each of the 96 segment edges. Make a deeper cut on every other one to
indicate what is the 48 position slots. If you don't have a bandsaw,
use a hacksaw to saw the slots.

Again, mount the disk on your lathe and make up a mounting for a piece
of a hacksaw blade to swing in and engage the slots in the disk. This
will give you the option of 96 or 48 position indexing, plus a number
of other positions less than 96.

This works much better than trying to get your drill to make a hole
exactly on one of the lines that will always align with a pin
arrangement. I've made them both ways, but found that the slot with a
piece of hacksaw blade works best. For easy attachment of the hacksaw
blade mounting to your lathe headstock, a magnetic base works very
well.

I hope this helps. If you have questions, go to my web site to get my
e-mail address and ask the questions that way.

Fred Holder
http://morewoodturning.net