Seaplanes Aircraft that typically take off and land on water...radio control seaplane discussions are in here.

Do I have a problem?

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Old 01-02-2013, 04:29 PM
  #1
Gray Beard
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Default Do I have a problem?

This is my first float plane and I was just able to get it in the water for the first time today. I have flown it from land and got it all in flight trim and worked out any bugs I had.
I wanted to check it for leaks and see how well it floated. As you can see, it lists to the right quite a bit yet the lateral trim/balance is pretty good. Is this something strange and if the engine was running and I was to try a take off would it just come up level on step? Its too cold to be going to the lake with the maiden so it will probably be spring at least before I try a water maiden. I do have some time to make any changes needed.
No leaking but the stance is really bothering me.
Gene
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Old 01-02-2013, 07:36 PM
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red head
 
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Default RE: Do I have a problem?

It looks to me like you have the right float out of adjustment. Check and make sure they are both tracking true. ENJOY !!! RED
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Old 01-03-2013, 03:31 AM
  #3
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Default RE: Do I have a problem?

I agree with RedHead.
Beautiful job on the plane.
The float appear to have different incidence.  Both seem to be rigged with the nose too high.
You want the chord line of the wing to be 3-4 degrees positive compared to the top of the float.
As it's rigged now, the floats will hold the nose down and make it difficult to get airborne.
Both floats should have the same incidence and should be parallel when seen from above. 
Some advise toe-in of the floats but I have never found that to be necessary. 
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Old 01-06-2013, 04:13 PM
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Gray Beard
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Default RE: Do I have a problem?

Thanks, I did post in kit building too and got a lot of advise. The left float was 1 5/8s inches behind the right, once I got that fixed the plane floated great but now I'm working on the incidence problem. I put the top of the floats at zero incidence and then measured the wing, it was at a minus 5 degrees and I have to raise the front of the plane 2 1/4 inches to get a plus 3 degrees incidence on the wing. At least it was floating level, that part I figured out pretty quickly.
First float plane and I need all the help I can get. I have flown it a lot to get it in good trim from land before I put it on the floats. It's a fun little plane with a lot of surprises in flight. Not a trainer in any way but it has a lot of the same features. It sure self rights itself when inverted and the controls are released and it's very easy to land.
Thanks again.
Gene
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Old 01-06-2013, 06:26 PM
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JohnBuckner
 
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Default RE: Do I have a problem?

High GB just noticed your thread here. What the others have said is dead on, in those initial pictures The float incidence between the floats is way off. Now the float displacements on the Swoose is somewhat marginal especially with the heavier engines. Thats certainly the case with my buddys sixty two stroke powered Swoose.

This marginal bouyancy situation will definately cause problems when the floats are not the same with each other. You need to get the wing at least 2 to three degrees positive to the tops of both float decks. If not when attempting to take off on the step when trying to rotate the rear of the floats will dig into the water and its just like slamming on the brakes. When the airplane is sitting on the workbench and cribbed with the top of the floats level the tail should be just perceptibly low. The tail should never be tail high.

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Old 01-09-2013, 04:15 AM
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alasdair
 
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Default RE: Do I have a problem?

Hi, you need to rig both floats at the same angle.
I'd start by disconnecting that link between the air and water rudders. It is asymmetric and will always cause problems. The water rudder is best connected using a plastic snake from the servo, down the float attachments, and back to the water rudder. That way it does not stress the float and move it out of position.

I generally rig my floats with the top surface parallel to the tailplane, and that has always been pretty good. In the past I have tried varying the float angle up to plus or minus 5 degrees from that, but my conclusion was that having the float top, and planing bottom, parallel to the tail is optimum. If you make wing incidence too positive, then as the model starts to plane the nose of the floats is force down and you get directional instability.

Your total buoyancy looks OK to me.

I don't know ho rigid your mounting is, but I always recommend a tie bar or two between the floats to keep them parallel. If they can diverge while planing you get a sudden grab, and turn to one side.
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