Yahoo Groups archive

MOTM

Index last updated: 2026-04-05 20:20 UTC

Message

One more Mega-Rail concern

2000-02-01 by Paul Schreiber

While I've got my mechanical hat on......

There is one major "worry" about fixing the rails to the *top*
and *bottom* surfaces.

Tolerances of cutting the wood!

See, in the current 19" scheme, the 2 "prongs" at the end of the MOTM-19As
are wider than 'normal'. This allows each rail to "wiggle" in a vertical
slop of
about 0.075".

This allows for panel accumulated tolerances (ie Joe Pavone's rack-o-MOTM)
to
be accounted for.

What has me worried is that wood is not "precision machined" to 0.002 inches
like
the panels and rails are! So, I can see mucho problems with a *fixed*
top/bottom
rail (never mind Hendry's scheme of bolting 12 things in the middle). I can
see the
bottom set of panel holes, in the bottom rail being off with respect to the
screwed-in
bottom rail.

The beauty of Moog's wood rails is "who cares?" As long as you allow slop in
the *overall*
inside "lip-to-lip" dimension, you are home free (remember, he used black
*wood screws*
to hold the modules into the *wood* rail). You start at the bottom, screw
those in flush to
the bottom board, and the top edge of the top-row panels fall "where-ever"
(as long as they don't
overlap the top edge!) Who cares if there is a 0.040 gap? You'll never see
it!

You *will care a great deal* if there is a 0.040" mis-match in the mounting
holes and the tapped holes
in the rails!

I am beginning to see that having 2 strong (oak, kiln-dried pine) wood rails
is looking good.

Now, you *still* need the center bar to joing the rows to each other.
BUT...that can be side
mounted.....

Paul S.

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.