Pilot-1 Piper PA-12
34" V bottom Floats
The PA-12 is finally done! Hope that you like it.
I finished the floats with Z-poxy and (2) layers of ¾ oz. cloth on the tops (so I could easily wrap around onto the bottom) and one layer of your 2.3 oz. on the bottom. I let in carbon fiber at the step (as you can see in the picture of the float on the scale) to strengthen that stress point).
The final weight of each float is 6.5 oz. painted with spars, balsa top strip, plywood inserts at the mounting points and a balsa cap on the back ends to mount the water rudder. The float mount (5/32” music wire w/ 1/16” cross ties) weighs 6.3 oz.
The 1/6 scale plane weighs 97.4 oz total including floats w/3900mAH 4s Li-po pack ready to fly. The wing loading is 19.73 oz./sq. ft. and the wing cube loading is 8.88. Hobby Lobby indicates a flying weight of 5 lb. on wheels with a 3s pack. This float version is almost exactly 6 lbs. with a larger motor and a 4s pack!! I had to modify the battery tray to allow the battery to move 1.5 inches further forward into the motor mount box to balance the plane without adding any nose weight at all.
The water rudder is custom made from brass tube, strip and aluminum. It is actuated from the rudder via Kevlar thread and SS guides.
I will send you some pictures after I get to the lake next week and let you know how it flies.
Excellent Job Tom, 34" floats Only 6.5oz per float! This shows why foam floats are the only way to go!
Thanks for the pictures and great work!
On The Water...
With fifteen flights on the PA-12 I can tell you that the 34” long, 4 3/8” wide floats are a perfect match for this plane! Plenty of floatation and they look very good.
With the AXi 2826/12 motor and a ThunderPower 3900 mAH 4s Li-Po the takeoff run is about 30 feet with a strong climb out (holding some right rudder). There is no tendency to nose over at all even with neutral elevator. The power loading is 103 watts/lb. with a APC 13x7 sport prop. It flies in a very scale manner at one-half throttle drawing only 13.6 amps. Flight times are 10 to 15 minutes depending upon how much of the time is spent on scale like aerobatics (loops, rolls, Immelmens, stall turns, etc.) Landings are a dream with a touch of power on final providing a nice descent rate and a smooth flare. Out of the first fifteen landings I bounced only once when I was a little too hot.
If anyone would like to duplicate this wonderful plane, I set the float step 3 ¼” from the leading edge of the wing (1/2”) behind the C.G.. The float spacing is 14” between center lines. The distance from the top of the floats to the bottom of the fuselage is 5 1/8” giving a prop clearance of 2 ¼” over the top of the floats. The stabilizer is parallel to the top of the floats giving the wing a 3 ½ degree positive incidence. I also gave the wing a ¾ degree wash-out at each wing tip to help make less likely to have the left wing tip drop as you approach stall speed on landing flare.
Thank you so much for providing the foam cores for this plane. You can rest assured that the angles, step location and proportions work well when it comes down to the acid test of performance.