45 Mono w surface drive rudder position?

[Greg Moss]

I'm cobbling together an old hull I've had for years, not sure what it is, and I have a choice of 2 rudders with different pivot distances from the transom.

What is the effect of rudder distance from the transom and relative to the prop? How far behind the prop is too far? I'm setting the rudder and turnfin positions roughly like the Seaducer setups I've found online but any advice will be greatly received.

Cheers

 

[Ted buckley]

I'm cobbling together an old hull I've had for years, not sure what it is, and I have a choice of 2 rudders with different pivot distances from the transom.

What is the effect of rudder distance from the transom and relative to the prop? How far behind the prop is too far? I'm setting the rudder and turnfin positions roughly like the Seaducer setups I've found online but any advice will be greatly received.

Cheers

Hey Greg, I never run my Rudder behind the prop, but I found a good distance for the rudder is: (the halfway mark on the blade = the end of the strut/right before the Drive dog). I've set them up before this, and after this, with not very good results. I found that, the farther back you go with the rudder, the more problems you will have(i.e. hooking/forcing the transom up & bow down/ect.) Here is a good site: that Ron Frank put together that shows a lot about Good Mono setups.. www.modelpowerboat.com/forum/article/attitude.htm

 

[Joe Warren]

I'm cobbling together an old hull I've had for years, not sure what it is, and I have a choice of 2 rudders with different pivot distances from the transom.

What is the effect of rudder distance from the transom and relative to the prop? How far behind the prop is too far? I'm setting the rudder and turnfin positions roughly like the Seaducer setups I've found online but any advice will be greatly received.

Cheers

Mono hardware is Normaly set up so the leading edge of the prop & the leading edge of the rudder blade are in line. This will put the prop wash just behind the rudder blade. Most sharp V mono`s had short hardware brackets. Some Shallow V or flatter bottom boats needed the longer hardware brackets to pull the boat around in the corners. John Finch wrote a Great Book On Mono hardware & placement the publication is ADVANCED R/C Boat Modeling. p.s. the hardware brackets is what changes. If you run long brackets on the rudder You will want long brackets on the stut also. same for the short brackets. This will keep every thing in line. hope this helps get you back to running? if you doubt where the props wash is exiting? lay a small straight edge across the back (working side) of the prop. this is the angle the water is coming off........ B)

 

[Greg Moss]

Thanks a lot for the help.

I've dug up some extra info through that link and after thinking about it it's pretty clear what to do for a test. I should be able to work it out from here. That and a bit of lake time.

Cheers