Good explanation of what can be sometimes a very difficult thing to get accomplished.

A good friend of mine has built about a dozen airplanes, most of them different makes and models, and including some biplanes. And all of them were put on floats. And every one of them had great off the water performance. So one day I asked him how much time he spends trying to get the rigging right on all those different planes? He explained that his method is quite unusual compared to what others do, but it works well and is not very difficult or time consuming. So here is how he does it.

He said that since he typically sells airplanes on land gear and not floats, that he always has the CG of the aircraft on wheels. So when he puts it on floats his obvious goal is to have a similar CG as when on wheels. Following his experience and general basics like the distance of the floats to the fuselage, the throat (incidence) angle, spreader width, etc., he installs the floats. Once that is done he literally puts a pipe under the step of the floats and rolls the airplane around on a flat floor until the aircraft sits level. Where the pipe is in relationship to the step tells him if he needs to move the floats fore or aft. So then it is a simple thing to shift the floats to the optimum position, and he's done!

I thought that was a bit crazy until one day when I was talking to JJ Frey (who used to run EDO float corporation and also wrote the book "How to fly floats") and he said that sometimes they did the same thing at EDO, as rigging so many different types of aircraft was difficult without a lot of trial and error costing a lot of time and strut material. So I guess my friend's method wasn't so unusual after all.

I guess I'm just lazy. I try to copy rigging of other people (like you) that have already figured it all out! So thanks again for sharing.

Paul