Originally Posted by workinpr0gress (Post 196684)

Bly, do they give a trim/tilt range in deg.?

Originally Posted by bly (Post 196693)

Carmen said he would call the factory. I am getting nothing but irritated here. See you bruce.

http://i1230.photobucket.com/albums/...1/P5230023.jpg
This is my new retractable carbon fiber riggers I am prototyping. Then I have to come up with a name for the new company? Nobody has a cam clamp retracting rigger like these. The best of the best.
http://i1230.photobucket.com/albums/...P1010015-1.jpg

http://i1230.photobucket.com/albums/...s/P1010032.jpg

http://i1230.photobucket.com/albums/...s/P1010094.jpg

Originally Posted by Bigshrimpin (Post 197017)

fs - take a look at this design from potter. If I were ever to build another bracket . . . this is the design I would pick.

minimum setback . . . allows tabs . . . easy build.

http://www.wellcraftv20.com/gallery/...er_4708087.jpg

Originally Posted by Bigshrimpin (Post 197083)

It's similar in design to how intrepid builds their transom.

I'm not sure what you mean by this question . . "I wonder if the water separates off the transom enough to reduce the drag with such a short extension?"

you see any high performance racing boats or bass boats with 30" setbacks? nope! Most jack plates are 10" maximum. The bracket is 4" off the water when you are running . . . so it's a non issue. The reason the current armstrong, hermco, stainless is deigned the way it is now is so you can convert/retrofit an i/o and get full tilt of the outboard with a nice swim platform. None of the popular brackets are designed with performance in mind.

Originally Posted by FishStretcher (Post 196673)

I did some stress analysis on a 24" bracket with (importantly) a center rib in the flotation volume.

The center rib helps a lot.

The loading is for 5 Gs. (not 10) Plus full thrust from a 100 hp outboard. Something sort of like the loading you might see landing after skipping off the top of a wave.

The deformed shape is magnified 50 fold so you can see what happens.

A rib that goes from the real transom to about halfway between the lower two outboard mounting holes seems to be an important structural feature.

Yield strength for this aluminum is ~180 MPa, but repeated stresses above 50 MPa would be a bad thing, in very general terms. I expect the loading from the outboard holes to be much lower, as the stress is distributed along the casting, not just inside the bolt holes.