CG on Rigger

[Randy Cartright]

On a rigger should the CG be about the middle of turn fin? I got a rigger that turns all kinds of funny. the CG is about 1 1/2 inches behind turn fin. Wondering if this may cause some of the problem. Thanks

Randy Cartright

 

[John Finch]

Location sounds ok. what does the boat do in the turns?

 

[Randy Cartright]

Location sounds ok. what does the boat do in the turns?

John

The boat seems to over steer in turns. Like bad servo,runnung 1/4 scale futba now did the same with 1/4 scale Hy Tec. I have changed radios rec. and transmitter, so thought the CG may be off. Thanks

Randy Cartright

 

[Josh Stollfuss]

How long is the rudder?

 

[Don Ferrette]

Can I ask what type of rigger we are talking about? Manufactured or scratch built? :unsure:

 

[John Finch]

I agree with Don on the need to know what boat design.

 

[Dan_Cousin]

I agree with Don on the need to know what boat design.

Check your rudder and make sure its not kicked back. That will lift the back and make the front do funny things. With a speed master rudder the front edge needs to be straight up and down not the back.

 

[Preston_Hall]

CG sounds good. Make sure the TF is pointed straight. The rudder has to be of sufficient length. Props can do things too.

What does it do in the turns?

CG too far forward will cause an agressive hooking. Too far back and the boat is lazy. Anything in between sounds like something else is off.

 

[John Finch]

CG sounds good. Make sure the TF is pointed straight. The rudder has to be of sufficient length. Props can do things too.
What does it do in the turns?

CG too far forward will cause an agressive hooking. Too far back and the boat is lazy. Anything in between sounds like something else is off.

You got it backwards Preston. Not trying to slam you, but if the cg is too far back the boat tends to spin out. I think maybe you were refering to the turn fin location. If it's too far back the boat is sluggish. Hey, were coming down to Chesapeake Saturday to run boats. Race or no race, we need the water time. Come on out!

 

[Preston_Hall]

Yup, I meant turn fin location, not CG.

 

[Randy Cartright]

Yup, I meant turn fin location, not CG.

Ok sorry about taking so long to get back.The boat is a Falcon Rigger with a gas engine, the boat is built by Todd Gunder. Looks like a cross between a Crapshooter and Eagle. Seen some of his boats run they did good. The turn fin is stright no up or down angle The rudder is 3 inches below the the rear sponsons. Tried a 1667 and a 3016 prop did not make any diffferance. On my other riggers the CG is closer to turn fin, that is the reason for asking. Thanks

Randy Cartright

 

[Don Ferrette]

Yup, I meant turn fin location, not CG.

Ok sorry about taking so long to get back.The boat is a Falcon Rigger with a gas engine, the boat is built by Todd Gunder. Looks like a cross between a Crapshooter and Eagle. Seen some of his boats run they did good. The turn fin is stright no up or down angle The rudder is 3 inches below the the rear sponsons. Tried a 1667 and a 3016 prop did not make any diffferance. On my other riggers the CG is closer to turn fin, that is the reason for asking. Thanks

Randy Cartright

Randy what are you using for a steering servo & at what voltage?

 

[Randy Cartright]

Yup, I meant turn fin location, not CG.

Ok sorry about taking so long to get back.The boat is a Falcon Rigger with a gas engine, the boat is built by Todd Gunder. Looks like a cross between a Crapshooter and Eagle. Seen some of his boats run they did good. The turn fin is stright no up or down angle The rudder is 3 inches below the the rear sponsons. Tried a 1667 and a 3016 prop did not make any diffferance. On my other riggers the CG is closer to turn fin, that is the reason for asking. Thanks

Randy Cartright

Randy what are you using for a steering servo & at what voltage?

Don

Using 1/4 scale Futba servo, 2500 mga AA bateries,and going with 6 volts to reciver.With Y connection.

Randy Cartright

 

[Don Ferrette]

Yup, I meant turn fin location, not CG.

Ok sorry about taking so long to get back.The boat is a Falcon Rigger with a gas engine, the boat is built by Todd Gunder. Looks like a cross between a Crapshooter and Eagle. Seen some of his boats run they did good. The turn fin is stright no up or down angle The rudder is 3 inches below the the rear sponsons. Tried a 1667 and a 3016 prop did not make any diffferance. On my other riggers the CG is closer to turn fin, that is the reason for asking. Thanks

Randy Cartright

Randy what are you using for a steering servo & at what voltage?

Don

Using 1/4 scale Futba servo, 2500 mga AA bateries,and going with 6 volts to reciver.With Y connection.

Randy Cartright

Y connection?? I run Futaba 1/4 scale servos plugged directly into my Futaba RX's with zero issues.

 

[John Finch]

How about a picture of the boat? That might give a good clue to whats going on.

 

[SteveSpear]

Load test the rudder servo.

also maybe maybe running to wet in the corners?

 

[John Finch]

One photo is worth a thousand words. Hey Steve........Don will have his gas rigger finished this weekend. Hang on to yours, we alsmost have a class.

 

[Don Ferrette]

Hey Steve........Don will have his gas rigger finished this weekend. Hang on to yours, we almost have a class.

Yup, shot the last coat of paint last night. B)

 

[Steve Sutton]

Hey Steve........Don will have his gas rigger finished this weekend. Hang on to yours, we almost have a class.

Yup, shot the last coat of paint last night. B)

Don,

is that old Roadrunner rigger that you ran at the Internat's in 1999?

 

[Don Ferrette]

Hey Steve........Don will have his gas rigger finished this weekend. Hang on to yours, we almost have a class.

Yup, shot the last coat of paint last night. B)

Don,

is that old Roadrunner rigger that you ran at the Internat's in 1999?

Nope, took lessons learned from that one & stepped it up. That was a kick azz boat though. B)