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rudder backset on mono


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#1 Mark Stein

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Posted 23 December 2017 - 08:33 AM

Curious what the reason is for the rudder to to 6" from the transom on a gas mono. Is it just to help the boat turn better or does it help settle the boat in the straight. I have run them close and extended on my nitro monos in the past but never really understood why it is where it is



#2 John Finch

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Posted 23 December 2017 - 09:12 AM

The turn fin and the keel of the hull dig into the water in a turn and the prop wants to drag the boat transom to the left.  So, the further back the rudder the better the leverage to control all those factors.  I have found that for example on a mono I used to run with no trim tabs that the closer to the transom the rudder was located the more it pushed the bow down to the water.  It tripped the boat more so than when it was further back from the transom just dragging along.  Most boat setups use trim tabs to accomplish the SAW attitude though and the rudder further back for controlling the boat in the turns.  I am sure someone else might have other ideas, as I am just speaking from what I have found on my deep vee boats.  I have found that running the rudder further back from the prop also helps control prop walk on my gas boats with the bigger props.  On my old nitro mono hulls with the smaller props the rudder could be located beside the prop and worked just fine..

 

John




Edited by John Finch, 23 December 2017 - 09:16 AM.


#3 Michael Costanzo

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Posted 23 December 2017 - 05:11 PM

if i could ask what also happens when the STRUT is father back?? does it make the hull act Longer and burry the nose? sorry to go off topic some..thanks,mike.



#4 John Finch

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Posted 23 December 2017 - 06:03 PM

Mike.  The further back the prop the more it pushes the bow down as the transom is the pivot point between the bow and the prop.  The height of the prop off the water also makes a difference as does the lifting characteristics of the prop.



#5 Mark Stein

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Posted 25 December 2017 - 02:51 PM

Thanks for the info. I have a Delta Force 45 sniper I plan to work on in the spring. Havent run a gas boat yet so all new experience.

Mark

#6 Michael Costanzo

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Posted 30 December 2017 - 07:54 PM

Mike.  The further back the prop the more it pushes the bow down as the transom is the pivot point between the bow and the prop.  The height of the prop off the water also makes a difference as does the lifting characteristics of the prop.

hi john,thank you very much for the reply,mike.