Jeff I just found a mistake in the rubber cup dwg.

The center hole should be 1.300 inches and not .5 inche.

I found it by trying to install the rubber bushings in the cups
you sent. That will take some weight out of them as well.
I can fix these in my lathe if we need them.

Here are the mounting dimensions for the rubber bushings.

Paul Lamar

Paul

OK

I will change this in my bolted version.  I bought the material today
and plan on making them in the next couple of days...When I am done I
will send them to you for inspection...Just to make sure, the distance
betweens C/L of cups is 21.5" right..

jeff

Correct but not critical. Each motor mount is custom built to suit
the type of airplane. If you need more distance go for it.

Paul Lamar