land plane to float plane??? - RC Groups
Thread Tools
Nov 29, 2001, 05:23 PM
Registered User

land plane to float plane???

im in the construction fase of a 1/4 super cub and want to be able to convert it to land and water use.
where should the two laning gear bars be placed?

the kit tells to have the servos sticking out the back but im going to move them is side so they dont get soaked.
i plan on making two slots for the each langing gear to be placed in
how do i keep the 2 bent peices of wire(landing gear) from shifting forward of backward?
Sign up now
to remove ads between posts
Nov 29, 2001, 07:49 PM
H301 Libelle Pilot
Dr. Jet's Avatar
Since you are still in the construction phase, use cross-bracing to keep the kanding gear from shifting fore and aft. Use tension members of music wire in an "X" fashion from front float attachment point to rear fuselage attachment point and visa-versa.
Last edited by Dr. Jet; Nov 29, 2001 at 07:52 PM.
Nov 29, 2001, 07:51 PM

"I'd rather fly off water, than eat!"

Your stock landing gear for the main wheels serve as the front float mounts - take the wheels off, and slide the float attachment devices(that are on the floats) on where the wheels were, then put the gear collars on to hold them in place.

If you build your own floats, then you can put the back gear where ever you want it. If you use floats like (Sea Commander? the fiberglass, premade ones), then you have to adapt your rear gear attachment points to suit the rear gear that comes with the floats.

Be sure to install "hard Points" where the rear gear screws don't want to screw something in to just balsa wood, like the old Pilot Tiger Moth kit did with the cabane struts(!) Hard Points are usually 3/16 inch or 1/4 inch on a model your size, aircraft ply. Cut into the bottom of the fuselage so you can mount the ply so it is smooth to the bottom of the fuselage. And be sure to put balsa triangle blocks above the hard points, on each side of the fuselage, to translate some of the shock of landing up into the fuselage side. "Spreads the load."

I use 5, nylon bolts that are several sizes smaller than 1/4 inch, to attach my gear - that way on a hard landing, the heads of the bolts will shear instead of the bottom of the fuselage tearing off.

That's on large models. Small models, I use 3 - and smaller nylon bolts than for the large models. I'm not an engineer (can you tell already?); this is the results of watching, then trying what the Sky Knights have been doing for longer than I have been flying off water (me for 20 years - them for 32+).

Good Luck! And - DO seal all places where spray could get into your model. I have learned that, after having models fly, then be tail heavy from water that got inside.

Nov 29, 2001, 11:23 PM
Registered User

im making my own floats

i love to build its the funnest thing i do...

is there any problems with the langing gear spread as in how far the have to be ahead of cg??? could i just use the stock gear placement(all ready instaled for ground use) and just make a rear gear slot??? of course use the x bracing i have heard that there must be a positve angle of attack when the plane is siting still????

plz tell me every thing that you know that would help me.

at the moment the ground landing gear placement is built in which i could adapt to float use just by taking the wheels off?

i would be 200% easyer to make a rear landing gearmount then making one farther ahead past where the "main" l/d wire is
Nov 29, 2001, 11:52 PM
Registered User
For models,

Floats should be 75% as long as the fuselage.

The step should be at or very shortly behind the cg.

All edges contacting water should be very square, not rounded to keep model from "sticking " to the water.

About, 20% of the floats should be in front of the prop to prevent it from nosing in when power is applied.

Nov 30, 2001, 12:27 AM
No retreat no surrender
newguy's Avatar

Wet flight

I have found when flying from water it is very advisable to waterproof your receiver as much as possible (due to shall we say UNSCHEDULED or VARIABLY ORIENTED water landings) I have had success with a well known birth control device made of latex. (Never had any unscheduled airplane breeding either). Just a thought. Jim
Nov 30, 2001, 12:50 AM

"Everything I know?" THAT will cost you!

Yes, keep the main gear as is, just remove the wheels and place the floats onto where the wheels were. As you noted, then place the hard points and the rear gear attachment where it fits.

I forgot to mention: To keep the float gear working as you want, if you are using wire, you will want a piece of metal going from the front L G wire to the back - I'm in the office, don't remember which way it slopes, but it runs from either the top of the front wire, to the bottom of the rear (near the fuse on the front L G wire, to near the float on the back L G wire)

I use gear from the 4-Star 60 on my Senior Kadet, and therefore don't need the braceing pieces on each side - the bolts at the fuselage hold everything in alignment.

Another tip: On that heavy a model, use Spreader Bars, or something similar - I use Kevlar thread, tied to the front right float attachment and across the the front left attachment; also a 2nd piece tied to the rear right float attachment, going across to the left rear float attachment and tied there. Some will also tie Kevlar thread to the front right float attachment and run it back to the back left float attachment point; same thing running from the left front left float attachment and run back to the back right float attachment point, and tied securely. Then you can tie a knot at the "X" point where the threads cross. This will really hold the floats in proper alignment upon less-than-perfect landings.

Floats: Dave W gave you some measurements that are right on; for your model, I suggest you have floats that are about 4-5 inches high at the highest point, and about 5 inches wide at the widest point, to give adequate floatation. When resting on the water, fully fueled (no, no - with the motor batteries in, I mean!) you want the model to sit with maybe 40% of the floats out of the water. Any lower and the model will not take off as well...and may have problems landing, too. Too much float has never been a problem for me; too little has been.

Also - bury a servo in the float (or both if it's windy) and use a water rudder...or you'll be rowing or wading more than you want.

I use micro servos, one in each float, use waterproof ones; best is to use Kevlar thread and make pull-pull linkage. My floats are foam covered with 1/16 inch balsa; 1/64 ply on the bottom front part (back to the step) and balsa behind; I use MMM double-sided tape to hold the wood to the foam; and I spray the floats when finished with Varathane to waterproof them. On a model as large as yours, make sure you have a strong mount for the attachment points (float to L G) or you will be repairing when a landing is not the best, or you hit a wave crest unexpectedly.

I'm all out of inspiration - ask more questions if needed.

Nov 30, 2001, 06:53 AM
Registered User


so on the rearward float landing gear there should be a peice of wire coming back from about where the main gear end?

on the cubs and super cubs the (mains for ground landings)landing gear makes a "V" shape at the point at the bottem of the "V" is the wheel attachment is.

so what your saying is make a bent rear "main" wire (float gear)and a wire that comes from forward back to the "main" this helps it not to move? correct?

after i have that them make the x bracing?

also how or where can i find the eyelets the attach to the music wire? these or sodered (cant spell) right?
i have a book that says to make the floats 80% of the fuse length
but the extra length wont hurt right?????

well thank you all
Nov 30, 2001, 07:01 AM
Registered User


does the angle that the plane sits in the water fueled and all afect take off and landing??? i have heard that the plane needs to sit with the nose slightly up (about 2-3 degs) is that true?

also i did most of the glue joints with the elmers interior wood glue the reinforced some of them with thin CA and the main joints with epoxy yes i knmow that glue softens in water but wont the covering block the water from entering?

since the plane will need tail weighti could use thined epoxy to seal the rear part from becoming water loged

and this is weed eated powered
Aug 03, 2010, 10:06 PM
Registered User
this is my make for people...
how to make floats for rc plane. (1 min 19 sec)

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Cool Twin float plane, lands on water or land Chipped Rotor Parkflyers 4 Mar 26, 2015 09:39 PM