Re: Mead screws

From: Roger Hamlett (rogerspamignored_at_ttelmah.demon.co.uk)
Date: 07/30/04 

Date: Fri, 30 Jul 2004 14:53:42 GMT

"Chris L Peterson" <clp@alumni.caltech.edu> wrote in message
news:bejkg0t5po8upgnql0fue4pqv986r7bnkh@4ax.com...
> On Fri, 30 Jul 2004 09:59:16 GMT, "Roger Hamlett"
> <rogerspamignored@ttelmah.demon.co.uk> wrote:
>
> >All the Meade threads are imperial.
> >On the tube, they use 4-32UNC, 8-32UNC, and 10-32UNC. The '4' thread is
> >the small one on the back of the actual arms, and the screws round the
> >scope rings on different models, and places, are 8-32, 10-32, and
12-32. I
> >think yours will be the 10-32.
>
> Roger-
>
> I think you've created some screw types that don't exist.
>
> #4 screws are either 4-40UNC or 4-48UNF (that is, coarse and fine)
> #8 screws are either 8-32UNC or 8-36UNF
> #10 screws are either 10-24UNC or 10-32UNF
>
> Left off your list are 6-32UNC and 6-40UNF.
>
> By far the most common small screws used are 4-40UNC, 6-32UNC, and
8-32UNC. I
> doubt this little 2045 OTA is using anything as big as 10-32UNC for a
finder
> bracket- there is nothing that large anywhere on my 12" LX200 tube.
Actually, you can get 4-32, it is a special coarse thread for alloy. I
have the taps and dies for it here. However I think you are right that the
#4's on the back of the OTA bracket are -40. The others on the OTA, are
all -32. I just remmbered the Meade small screws as all being -32, and
extended this, one screw too small. :-)

Best Wishes