Jerry Hey wrote:

Paul,   I am going to make a Shertz beam motor mount.  Seems like the
ideal width would be 29 inches to the Barry Mount centers same as on
the MMP.  Do you agree?     Braces that catch the forward three bolt
holes on each side will be included.  Materials:  you recommended .063
x 2" x 1" 4130 channel.  I would have to have that sheared from sheet
and folded.  What is the comparative strength of A36 mild steel 2" x 1"
x .125" channel?  Could it be lightened enough to make it a good
alternative?   Jerry

Make it a 4130 hat section. Make out of
4130 and 2-1/4" wide by 1-1/2" deep with 3/4" lower flanges. This will give
you room inside the hat section for the aluminum rubber bushing sockets.
Or just weld sockets in the there with some 4130 scrap. I prefer that method
as long term bi metal corrosion would be less of a problem.

Have the sheet metal shop shear and  bend up a bunch. I am sure you can use them 
in the future. You could also sell them to people that want to weld their own. 
You can cut them to length later.

Mild steel not recommended. The fatigue limit life is one quarter of 4130.
You should put a couple of 1/2 inch square 4130 steel tube diagonal braces
on a long Schertz beam 29 inches center to center. They do not have to be exactly
like this drawing. Almost any configuration would work fine. They do not have
to be forked as shown in this sketch.  Just a couple of simple gussets will
do the trick. Send me a sketch of the way YOU want to do it and I will 
check the stress.

Paul Lamar
 
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