On 2007-12-09, Bill Schwab wrote:
Jim Wilkins wrote:
On Dec 5, 4:23 pm, "DoN. Nichols" wrote:

[ ... ]

Or -- start out with the thing set up for the longest, mark them
with one color of paint pen, then the next shorter, (skipping the ones
already marked) and mark them with another color of pen, then finally
cut the shortest, skipping the marked lines, cut the next longer (going
for the one color) only, and then the longest (going for the first
color).
Then wash off the paint with an appropriate solvent.

[ ... ]

Interesting. Is the paint pen intended to be spindle mounted?

No -- you simply keep the engraving cutter too high to touch the
workpiece, and draw lines using it as an indication. These are not
precise marks --just enough to tell you to not cut there yet.

The simple final answer was to write down the ending points and look
at the dial to see which one to use next, instead of trying to
remember everything. I only mentioned this because it was an
unexpected problem.

No offense to anyone, I kinda like that idea

That works -- if you are using a rotary table and a dial on the
hand crank. But if you are using an index head (which is what I would
be using, and which has no dials) you can set the arms so you move from
one arm to the next (perhaps with two or three full turns between arms
if you are marking angles greater than what a single turn of the crank
provides. In the case of my index head, which has a 40:1 worm, you get
nine degrees per full turn, so for the ten degree steps you would need
to go one full turn plus the distance marked by the arms, which select a
certain number of holes on a circle of N holes. Once you reach the new
position, you move the arms (which are locked together) so instead of
the trailing arm touching the index pin, the leading arm touches it, so
when you crank again, you again move to the trailing arm.

For the 5 degree and 1 degree motions, you will be less than a
full turn, making things even simpler.

Hmm ... You don't need to set the arms for the 10 degree setting
anyway when just marking -- you simply set for five degrees, mark the
starting position as blue, then crank five degrees out, mark in red,
crank again for blue and so on until you reach the starting point. Then
you set stops to limit the travel, lower the cutter to make contact with
the workpiece, and cut, then crank out two five degrees steps and cut
again. Once that reaches its start, you crank out five more degrees,
set the stops for the medium length lines, and cut, again going in ten
degree increments until you have completed the circle. Then you reset
the arms for one degree increments and the stops for the shortest line
length, and crank and cut on any stopping place which is not already
cut.

Then you wash off the paint with solvent and figure out how you
are going to engrave or stamp the numbers for the long lines.

The index head reduces the chances of mis-reading the dials, but
you need a special index plate to do things like 127 (for making metric
transposing gears).

Enjoy,
DoN.

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