Phil, Re your question about rod end bearings for attaching a rudder: I downloaded the Aurora catalogue http://www.aurorabearing.com/2003-04_Internet_Catalog.pdf and from a quick read it would appear that the load you are concerned about is the axial load when used as a rudder hinge. For a three piece rod end, such as the MW3 used in the Dean hinge solution, (see article on Mark Langford's site) the maximum axial load should be no greater than 10% of the radial load. For the MW3 the maximum radial load is 6,805 Newtons which is the force exerted by a load of 694 kg or 1527 lb. 10% of that is 153lb which would be the ultimate load. If you are designing for the utility category the limit load is calculated at 4.4g and if a composite structure the ultimate load is 2 x limit load ie 8.8g. I guess that means the weight of the rudder should be limited to about 153/8.8 = 17.38 lb. Of course this calculation assumes that the whole rudder load is being taken on one bearing. (It also assumes I know what I'm talking about)
For what its worth :-) Murray Gill
