Decided the first .188 bracket was hanging the cooler too high and too far forwards. It was touching the aft edge of the sump - no space at all for the oil cooler baffle to get in there. Here is a photo of the 3 brackets so far. This last one was made from 2.5"x2.5" .188 stock left over from one of the horizontal stabilizer spars. I weighed these. The .125 one per the Sonex guide was 85g (cut down 3/16" in width on both sides). The first .188 one was 104g. This latest one is 133g. Not bad for 50% thicker material and hanging the cooler about 1/2" farther aft and 1/2" farther down.
Brkt per Sonex guide in front, my 2nd try next, the latest one in back.
