FILENAMES:

Layout-tbl.jpg
Layout-tbl.gif
Layout-tbl1.jpg
Layout-tbl2.jpg
Layout-tbl3.jpg

DESCRIPTION:

These are pictures of a shop table for layout and assembly.

Posted by Ted Edwards <Ted_E@telus.net>. 

The following description was provided:

=================================================================

                   Layout, Assembly, Work Table
                   Ted Edwards, Ted_E@telus.net

Files:  Layout-tbl.txt, this file
        Layout-tbl.gif, a dimensioned drawing
        Layout-tbl.jpg, overall photo
        Layout-tbl1.jpg, view of a corner
        Layout-tbl2.jpg, leg attachment
        Layout-tbl3.jpg, leg bottom

I built a 2' x 4', 40" high layout/assembly/work table.  Since one of 
its prime functions is layout, I wanted the top to be quite rigid - less
than 0.005" deflection for a 50 pound load placed anywhere on the 
surface.

The table top:
This is 3/4" MDF (Medium Density Fiberboard) given three coats of epoxy
sealer/varnish.  After the epoxy cured, a sheet of 0.052" thick 5052 Al
was laid on top.  This sheet has a slight curve to it.  It was laid on
with the edges up.  The edges are held down with a frame of 1 x 1 x 1/8"
Al angle through bolted to the frame with #6 machine screws with nuts
underneath - no threaded ends sticking up.  This arrangement keeps the
aluminum sheet in good contact with the MDF.  I chose to miter and weld
the corners of the aluminum angle although this is not necessary.

The result is an *extremely* dead surface.  A ball bearing dropped from
as high as I can reach lands with a thump and sits there.  Anything that
does roll hits the 1/8" lip around the edge and just stops.  These
features have saved a *lot* of grovelling around on the floor.

The frame:
This was designed so that a 50 lb object placed anywhere will cause less
than 0.005" deflection.  My surface plate sits at one end with an MDF
cover to protect it when not in use.

The frame is welded 1" square, 1/8" wall steel tube with 6" stub legs.
The table legs were made separately, both as a convenience in building
and for ease of moving or storing.  While the 1" square tube was
sufficiently stiff for the ends, it would have allowed to much
deflection for the longer sides.  This was solved by using two pieces
separated by 1", joined to the stub legs at the ends and joined to each
other at the 1/4, mid and 3/4 points by 1" x 1" x 3/16" cupons.

The legs:
As stated above, these were built separately and are each attached to
the table top stub legs with four 3/8-16 setscrews.  Each leg consists
of a 17" long piece of 1 1/2" x 1 1/2" x 3/16" wall square steel tube
welded to a 17" long piece of 1" x 1" x 1/8" wall square steel tube.  1"
x 1" x 3/16" thick steel pads are welded near the upper ends of the legs
to provide sufficient length of engagement for the attaching set screws.
A 1/4" thick cap was welded to the bottoms.  This was drilled and tapped
for the levelers.  A piece of 1/4" thich rubber belting was glued to the
bottom of the levelers

I wished to avoid a shelf or diagonal bracing so that, while working, I 
could sit on a bar stool with my legs under the table not being bashed 
by bracing.  While I was willing to give up some rigidity for this, I 
was surprised at just how rigid the thing is.  A bump hard enough to 
wiggle it very much will slide it on the concrete floor in spite of the 
rubber pads.