missed a chance to buy someone's cast off which was perhaps no bad thing as getting it to the boat would have been difficult, but been having thoughts about the design for some time. What I would like to do is to use standard stainless tube fittings and make it out of 25mm pipe for the vertical and horizonal and bracing pieces. I wonder if 25mm tube would be strong enough ; wall thickness could be 2mm and perhaps lined with 22mm tube to avoid bending. Outboard not that heavy 3.5 hp but the crane arm needs to be about 80 cm. Any thoughts?
Will need a diagonal support in the bend, else it is probably too springy.
I would consider making it (having it made) out of 40mm tube to get a cleaner look and feel. To make it out of 25 mm tube will be way too flimsy in any direction to lift your outboard.. (especially if you like 80 cm outreach)
I've got some pipe at home and fittings for 25mm so will test in the garden with a weight on the end of the arm and see how much deflection there is