1520 plotter (was RE: Your VIC-20 is worth $300!!! W_at_W!)

From: Doc <doc_at_mdrconsult.com>
Date: Thu Jan 31 14:48:49 2002

On Thu, 31 Jan 2002, Tony Duell wrote:

> I have a real Myford dividing head. It's a 60:1 gearbox with the output
> spindle having an end (and an internal morse taper) identical to the
> lathe mandrel (so you can fit the chuck, collets, and so on to hold the
> workpiece). The input spindle has the division plate/index pin as you
> suggest.

  I'm seriously jealous.

> Whichever way you use it, it's ideal for cutting small gears. The
> division plates I have give you all numbers up to 50, and all even
> numbers apart from 88 (I think) from 50 to 100. You can get other plates
> for the other divisions, but I doubt I'll ever need them.

  OK. I've tried hard to stay out of this thread, but as a silversmith,
ex-welder/machinist, and devoted tinkerer, I can no longer sit still.

  This is not rocket science. Take the thing (the whole assembly) to
the local watchmaker. Get N+1 pieces made. Share. Or, with a good
indexing head and very basic diamond tools - don't flinch, my set for
the flexshaft cost ~$30 - you just do it. Find the OD, and get a rod
to suit. Count teeth, guesstimate (tm) the depth and width (ratio) of
the teeth. Do basic math. Start cutting trial gears.

  And, forget casting. In the size gear you're looking at, by the time
you remove flash, correct warpage, and polish the casting, you've pretty
much machined a gear....

        Doc
Received on Thu Jan 31 2002 - 14:48:49 GMT