Float Size?
11-03-2003, 10:16 PM
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Float Size?
Alright guys, I'm sure it's been discussed before but , I wasn't into float planes and I'm sure I didn't see it. I plan on trying my hand at float flying in the near future. I just built a new house on a 60 acre lake. I was thinking about getting a Seamaster but have decided that I would rather have a plane with floats. I have a plane called a Perfection kitted by Max Blose out of Waco, TX. It's similar to an Ugly Stik. I've had the plane for over 7 years and just got Max to cut me a new kit. I want to build the new kit with the ability to fit it with floats. Can anyone give me the basic rundown on floats as far as size, mounting location, etc...? The plane has a wingspan around 60" and I'll be using an O.S. 91 4-Stroke. Thanks for any input. Matt
11-04-2003, 08:40 AM
#2
RE: Float Size?
Float length: 75-80% of the length of the plane from the prop washer to the rudder hinge line.
Alternate rule: nose of float is 1/3 of prop diameter in front of the prop. Step under the 40% Chord point. Step is in the center of the float.
Step of float: under the 40% Mean Aerodynamic Chord point.
Hang the floats a little nose-down (3-5 degrees) so the wing will be able to make lift while the float is running horizontal along the surface of the water. (Top of float level-Wing at 3-5 degrees positive incidence)
Prop arc should clear top of float by 2".
Track of float: 25% of wingspan
Mount the floats rigidly. 2 aluminum landing gears and spreader rods between work very nicely.
Water rudder(s): should hang down no farther than the depth of the step.
Balance the plane in the same place that it would balance with wheels.
You don't need more engine, but dropping the prop pitch an inch is sometimes good. (use 11-5 instead of 10-6)
Mount your switch internally using a pushrod to actuate it.
Don't mount any of the electronics either at the top or the bottom of the fuselage....any water can slosh around without dunking the circuit boards, even if the airplane is inverted.
Seal the inside of the fuselage with a coat of dope/paint whatever to protect the wood.
Use styrofoam floats instead of hollow floats. Hollow floats are good for storing water.
We're here to help. You're gonna have fun.
Alternate rule: nose of float is 1/3 of prop diameter in front of the prop. Step under the 40% Chord point. Step is in the center of the float.
Step of float: under the 40% Mean Aerodynamic Chord point.
Hang the floats a little nose-down (3-5 degrees) so the wing will be able to make lift while the float is running horizontal along the surface of the water. (Top of float level-Wing at 3-5 degrees positive incidence)
Prop arc should clear top of float by 2".
Track of float: 25% of wingspan
Mount the floats rigidly. 2 aluminum landing gears and spreader rods between work very nicely.
Water rudder(s): should hang down no farther than the depth of the step.
Balance the plane in the same place that it would balance with wheels.
You don't need more engine, but dropping the prop pitch an inch is sometimes good. (use 11-5 instead of 10-6)
Mount your switch internally using a pushrod to actuate it.
Don't mount any of the electronics either at the top or the bottom of the fuselage....any water can slosh around without dunking the circuit boards, even if the airplane is inverted.
Seal the inside of the fuselage with a coat of dope/paint whatever to protect the wood.
Use styrofoam floats instead of hollow floats. Hollow floats are good for storing water.
We're here to help. You're gonna have fun.
11-04-2003, 11:44 AM
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RE: Float Size?
Chuck Cunningham's definitive articles on float design and setup are posted on the RCM website. www.RCMmagazine.com Look under "Requested Articles".
Jim
Jim
11-05-2003, 11:30 AM
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RE: Float Size?
The above posts are great and also you may want to consider tethering your engine to something solid in the fuse (like the landing gear block) with a steel fishing leader. I was at a float fly and a guys wings folded and the fuse went in the drink pretty hard. The engine went to the bot of the lake. I have it on video and the guy gave the video to divers, but they still never found the engine.
11-06-2003, 04:54 AM
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RE: Float Size - GP J3 ARF?
Have the .40 GP ARF J-3 Cub, and was thinking that using the .60 size GP floats would be a good thing since I will likely fly the airplane on some relatively rough water at the local lake... Will this work? Any "issues" I should be aware of? Thanks in advance for any thoughts.
Cheers!
Jim
Cheers!
Jim
11-07-2003, 12:29 AM
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RE: Float Size - GP J3 ARF?
LOL watch for the waves! if they get too big! and you hook a float in one while landing, it flips you over pretty quick! LOL Esperience talking. 2 ft is too high, 1 foot is too high. and possible 8 inches is too high of wave. didin't measure the last one, but sure made me bounce! LOL darn wake borders! 
Smoky.
PS on float tips. make sure you seal any exposed servo's IE flaps, ailerons. I use vaseline to seal the joint and gear extrusion for the control horn.
Smoky.
PS on float tips. make sure you seal any exposed servo's IE flaps, ailerons. I use vaseline to seal the joint and gear extrusion for the control horn.
