Offset rudder placement on catamarans

[Stephavee]

I have another newb question about FE boat setup. Im doing some winter modifications on my old catamaran and one of those mods is a new rudder. My question is what effect will it have to move the rudder further from the transom? I ran the rudder last year almost even with the leading edge of the prop (second picture) but what would it do if i pushed it back to the trailing edge (first picture)? also what about moving the rudder outboard more? These pictures are just for mock up only, im building a 6s 26" saw.P3130399.jpgP3130402.jpg

[Old Sloppy]

the further back the more leverage (grip/power) the rudder has.

For saw it is a very good idea because it acts as a longer hull and you can shorten the rudder for reduced drag.

I had a SAW cat, I mounted the rudder on the left sponson, the rudder drag ballanced the prop torque exactly.

the rudder was dead strait, with no crab angle at all.


Harry

[Stephavee]

Cool then how much rudder do you run below the hull i had a BJ 26ss rudder but was thinking about using this MG rudder because its alittle longer and the water pickup is lower. not going too crazy i got a BJ26 with leo 3674 1700kv/T180 esc. 6s build!

[Old Sloppy]

Keep in mind that the shorter the rudder the less steering you have.

I cut mine off just below the water pickup. (about 1/8" below the water pickup)

Harry