Re: A big ol' chunk of delrin

On 4/21/2025 2:37 PM, Joe Gwinn wrote:

On Mon, 21 Apr 2025 13:44:28 -0500, Snag <Snag_one@msn.com> wrote:
 

On 4/21/2025 10:19 AM, Clare Snyder wrote:

Don't be a wuss -chuck it in the 4 jaw and single point it. If you
grind your tool right you won't even need to heat form it - - - -
>

>
   The problem with that is that I'm not certain what the thread profile
is - probably acme but ... I was just thinking that I can make an
impression of the leadscrew , wax might work or clean the leadscrew well
and apply a release compound and mold one out of JB weld ... and use
that impression to grind a cutter . That piece of plastic is dialed in
on my 4 jaw , and ain't coming out just yet .

  From the discussion, I'd guess that it may be a ISO Trapezoidal
thread, specifically TR24x3.
 .<https://www.engineersedge.com/hardware/iso-metric-trapezoidal-threads1.htm>
 Otherwise, it's likely an Imperial Acme thread, 8 TPI.
 Measure the thread pitch to tell.  3mm pitch is 8.47 TPI, a ratio of
1.058 compared to 9=8 TPI, which is easily distinguished over the
length of the leadscrew.
 Joe
 

   It's definitely an 8 TPI leadscrew , moves the table .125"/revolution plus/minus a few tenths . OD is within a few thousandths of 15/16" . Tell me more about this imperial acme thread ... this machine is a copy of the RF45 , made in China in 2001 . I got it new IIRC in '02 or '03 . I've made a lot of stuff with this machine .
--
Snag
We live in a time where intelligent people
are being silenced so that
stupid people won't be offended.