That is correct. It is more "flying" then "floating"Not trying to put words in David's mouth, but I think that the floating transom is the fact that it has two small sponsons under the transom
that are very shallow to the strut, about 1/4" above. This is much like a 3 point, but aids in launching bigger props! Better yet maybe Andy will comment, after all it is his design!
Don
John,Hi John,I got a new gas rigger last year that Don Ferrette built for me as a one of a kind build that was too touchy for me to drive through the turns. He likes the touchy rudder while I don't, so I moved the turnfin rearward with the slotted holes that allow adjustment on the turnfin. I ended up 3/4 of an inch more rearward than original setup and the boat drove the corners the way I like to drive it. So, turnfin forward = touchy steering as the rear of the boat swings around easily. move the fin rearward = not so easy to swing the transom around. Most readers here already know that but for those that don't, this example might help, because we also need to adjust our fast turning boats to our own driving style.
David ......What is the floating rear end on Andy's new SGX? Explain.
John
What was the relationship to the C/G and the trailing edge of the turnfin when you got it right?
Thanks, John
Yes. My older sgx 45 has it and the gas rigger has it.Danny you have this setup on your boat?
Brad. Yes I do that and also search for the right amount of throw to get that pin to pin turn. I agree that most of the guys we race against that have difficulty running a straight line on the course or cut people off in the turn have way too much rudder throw on their boats. They just don't understand when you talk to them about it. They are so scared they won't have enough rudder throw if they get in trouble, but it is too much throw that gets them in trouble. If I help someone on the pond who is having issues driving, the first thing I usually do is reduce rudder throw on their transmitter. I like setting the servo horn with the linkage as close to the hub as possible for more torque and less throw with the rudder linkage just the opposite for max leverage rather than dialing it into the transmitter.John,
Have you ever tried leaving the turn fin forward, but reducing rudder throw and increasing rudder surface area (width and/or depth)? What I have observed while at races is that the boats that seem erratic in the turns have WAY too much rudder throw.
My personal set-up is such that the wheel on my radio turned to full peg makes that perfect pin-to-pin turn. I can't see a reason to have anything more than that.
Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine And Precision LLC
Thanks John, I'll bet your log also says you checked the C/G dry so you could see the variable as the tank empties right?John,Hi John,I got a new gas rigger last year that Don Ferrette built for me as a one of a kind build that was too touchy for me to drive through the turns. He likes the touchy rudder while I don't, so I moved the turnfin rearward with the slotted holes that allow adjustment on the turnfin. I ended up 3/4 of an inch more rearward than original setup and the boat drove the corners the way I like to drive it. So, turnfin forward = touchy steering as the rear of the boat swings around easily. move the fin rearward = not so easy to swing the transom around. Most readers here already know that but for those that don't, this example might help, because we also need to adjust our fast turning boats to our own driving style.
David ......What is the floating rear end on Andy's new SGX? Explain.
John
What was the relationship to the C/G and the trailing edge of the turnfin when you got it right?
Thanks, John
1 inch from the trailing edge of the **** Tyndall turn fun at water level to the CG with full fuel tank.
Hi John,Brad,
I am running gas engines and the problem is my cg is now at one inch behind the trailing edge of the turnfin so moving the fin forward puts the turnfin further forward from the CG. That screws up the dynamics. I am thinking the gas boats I run put more weight behind the boom tubes than a nitro boat, so getting those dynamics correct on a gas boat would mean somehow getting the engine more forward in the boat. This is where the sport boat has an advantage over the rigger in that the engine can be moved more forward because there is no rear boom tube. That is the primary reason My fastest cornering boat is a wide body sport boat converted to a rigger with only a forward boom tube. I suppose I could extend the front sponsons more rearward to get the proper dynamics. I believe the crapshooter has already done that for your setup and with a lighter nitro engine you can be spot on.
John
BINGO..Hi,
the reason that the JSEs turn good are that the sponson has no slip edge outside and the sponsonboom are so wide that the rigger can not easy roll outside . 1983 i build my saw electric rigger with similar wide and only straight cut sponson . at less speed it turn very good without turnfin . And with lower 2-4 degree angle of attace of the sponson it turn better and with high angle 5-7 degree it will stay hard on the watersurface getting no side grip.
But Brad Christy has the best. Place the turnfin forward of c.g. and you need only a smaler turnfin and a smaler ruder . You have to level it out that all the force are not to strong
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