My buddy and builder, Flaps Laffert and I were brainstorming about designs or configurations we hadn't tried on floats. Has anyone tried any of these and can give us advice or point us in the right direction. We do have all the old articles on float flying.

I do have a TwinStar on floats so we've done a twin on floats. Flies the same, really.

I also tried some "tri-gear" or tail dragger floats. I had these on an old Stuntwagon. I never did work with it long enough to get down how to best take off and land. I recently dragged it out and did a refurb. I wedged in a larger tank, it originally had a 4 ouncer for a .46.

1. Big single float. (Not a flying boat-they are too easy.) I have read that float length is equal to fuselage length. Step is at 40% of MAC or just behind the CG. Anyone have experience with these?

2. Canard on floats. We have a tractor canard and a pusher canard. The CG is way back in the middle of the fuselage compared to a normal plane. Would we use the same size for twin floats, but put the step back in relation to the CG? I guess so, but this would leave the rear section of the float pretty short. Any ideas?

3. Flying wing on floats. These guys are short and the floats may be longer than the fuselage. I have a Beast kit, but haven't started it.

4. Delta on floats. I have seen photos of a couple. They may work out OK. They are longer than a flying wing and usually have a low wing loading.

Who has experience with any of these type planes on floats? We are open to ideas and looking for a project.

Deltas, or deltas with canards are high angle of attack aircraft.
To me this MIGHT mean lots of power to build up speed to rotate the nose cleanly.

USN had a full Delta jet seaplane. SEA DART ??? ALL engine and wing.


AVRO of England built a terrific jet seaplane. Can not remember the wing shape.

All seaplanes need lots more power because of the wet STICKY water AND the choppy waves to smash thru. Both EAT horsepower like crazy till the plane breaks free.

My buddy and I are on our 14th seaplane. That one was the TwinStar on floats. We just wanted to try something different. We never under power anything and, you're correct, seaplanes do like more power. Besides the water, you have the extra weight and drag of the floats.

Here's another one I should have added: retractable main float or floats.

I think it was Saunders Roe with the jet seaplane and not AVRO.

Evan-RCU who posts here had the coolest little delta flying wing a coupla' years ago in Knoxville. Faster than white on an ape, and unbelievably maneuverable. Tiny little thing. I think it had a .15. pics of it exist in this forum. Search for Evan and you'll probably find it.

Timesaving note: here it is:

Canard: WHy not just use the regular 75% float rule and put the step a little behind the balance point where it is supposed to go? This would be particularly appropriate for a Vari-Eze or Velocity-type Canard. Curtiss Ascender would be waaay cool. . For a tractor canard, I agree you would have different looking floats with very little afterbody. Maybe a Rutan quickie with floaty pods on the wingtips and a tail float.

Here's some pictures of the retractable floats on my 104" WS PBN Nomad from a G&P Sales (Bill Price) kit.

You are right Ed. It had the intake at the top of the swept up bow. Pilots raved on its flying.

Our USN Sea Dart broke backbones with the rigid retractable main center skid/float.

Old mind drops off bits of information.

Actually they fooled around with 2 or 3 configurations on the seaDart. Most successful (relative term: the project was cancelled) were two water-skis angling out of the hull. The SeaDart at Eaa Lakeland is of this configuration. All films I have seen of it were in high waves--3-4 feet.

Ed, Here are a couple of pics of the same Somethin Extra on two different float setups. I flew it for five seasons on a pair of .40 size Great Planes Sport Floats. Best float flyer I ever had. Finally tore one of the floats off (dumb thumbs) and it sat for a year. I missed it a lot and remembered that it always sat pretty high in the water. Insterad of fixing the beat up float, I remounted the good one in the center and carved some tip floats. I flew it most of this summer and got another couple of dozen flights and another hundred or so landings.

The single main float rig worked OK but it was some different. The all up weight was about a half pound less but the water handling needed new technique. With the V bottom main float and the tip float bottoms set a half inch above the surface of the water with the A/C static, one or the other tip float would drag in the water. During the takeoff run, due to a long ingrained bad habit, I was using only rudder for laterl/directional control until liftoff. These tip dragging takeoffs were really ugly. Of course the answer was to get on the ailerons right away to fly the wings level as soon as possible. Even old dog's can learn new tricks.

Hope you and Flaps keep experimenting. It's half the fun.

Paul

OK, take your single float Somethin' Extra and make all the floats retractable. That's what we are thinking about.

I recall I read that the bottom of the tip floats should be even with the top of the main float.

I also have the photo of EvanRCU's delta on floats. I think it's a Jerry Smith Outlaw delta which isn't made any more. We were just looking for something different. I think we are going to order some retracts and make a center float for a .46 sized plane we have or an easy ARF. Probably use a second set of retracts (mechanical) for the tip floats.

I have an old article and 3-views of the plane that were published back in 1975 in RC Sportsman magazine. For an experiment, we'd rather mod an old airplane. Also, it seems that a high wing plane like a Stick or one like the Somethin' Extra with plug in wings would be easier to handle. With a low wing, it would be a pain getting the wing in between the float and fuselage.

My curiosity with the single float was from what I have read. It is stated in some aritlces that the single float should extend 80% of the prop length in fromt of the prop disk. This makes a fairly long forebody and a shorter afterbody on the float. I guess the long float out in front is to keep the front from digging in during take off and landing. I don't know. Also, the step on single floats in supposed to be deeper than the step on dual floats.

Jim, the "Skeeter" as I call it is still alive and well, it was the belle of the ball last weekend at a float fly on lake Murray near Columbia, SC. 36" span, OS .32 on a pipe for power, and it's a handfull, but yes fast a manuuuuverable. I've had a few canards but never on floats, the only canard I have now in my hanger is a lead sled slope glider. While it would be interesting to have a canard on floats the only reason would be for a very stable slow fly design, it would be cool to try it though. I've tried most everything else, floats of different configs, boat hulled planes, helos, on floats, hovercraft. My fave is still my Quaker on floats. The Northstar is high on the fave list too. The good thing is they're good in the snow too! My first float plane was an old Rebel Bipe from Lanier in 1976, that was a handfull too... I've got a Tower Hobbies trainer with four OS .25's that'll be on floats next summer...

Ed.
Thanks for the tip about tip floats being 1" higher than the top of the main floats.

You mean somethin' like this?




Cool old stuff here: http://aeroweb.lucia.it/en/history/pegna1.htm

This would probably be easier to build:

Jim,

The top 3-view is the basic idea. Doesn't the end of the float need to extend out past the prop?

I have an old Heckler 3D. Flaps is swinging some arcs to see where we'll need to mount the retracts. He thinks we'll need 9" legs to clear a 12" prop. Right now I have a GMS .47 on it, but with the extra weight, we might need a .61. We are planning on fixed tip floats at first. This will just be a lash-up to see if the retracts work. Later on, we can make a new plane with retract tips and a better looking fuselage.

As soon as we get building, I'll post pictures.

No, the float doesn't >>Have<< to extend in front of the prop. It really helps with docking as the float nose acts as a bumper. Otherwise, as long as the float keeps the prop out of the water it will work. Last time we met, I had just slapped some old floats on my plane and they did not extend past the prop.

All the "rules" about mounting floats are not chiseled in granite, but in silly putty. Everything is a tradeoff.

Look up "Watts Linkage". It may be a useful trick up your sleeve with what you're doing.

I've always wanted to do a SEAMASTER on floats

Jim,

I can understand short floats when they are dual floats, but I'm not sure about a single float. Every single float plane I have seen, full scale or RC has had the float a good bit out in front of the prop. That's why I asked if anyone had experience flying a single float plane. You don't see many of them other than flying boats and that's not really the same.

The retracts for the Heckler, retract float experiment, are due in on the 7th. Flaps already has the geometry drawn out and the rails for mounting the retracts installed. We are going to hold off on retracting the tip floats until we get the main float working. If this kulge flies OK, we'll probably design a whole new plane with main and tips retracting.

Ed, on the Somethin'Extra/Great Planes .40 single float combination, the protrusion of the float was dictated by the shape of the pieces. with the step located 1/2 inch aft of the spar (CG), the nose of the float ended up 4 inches in front of the prop disc. Another aspect of the single float rigging was to shorten up the float struts so that the 11 inch prop cleared the top of the float by only an inch. I reasoned that lowering the thrust line would minimize the pitch down moment on throttle application. Splash rails on both fwd chines have made spray through the prop not much of a problem. In rough water with higher swells, the two float rig with the floats 2 inches below the prop disc did work a bit better. The single float setup works very well on calm to 3 or 4 inch wave water.

I had thought some about a retractable float machine also, and have some concern over extra weight and CG shift during retraction. Will be real interested to hear how your experiment works out.

Paul

We were actually talking about a Somethin' Extra as the basis for our next plane if this one works out. I feel you need a high wing or plug in wings so you don't have to go between the float and the fuselage to get the wing on as you would for a low wing plane.

The modified Heckler isn't going to be pretty. The float is a wide, built up float about 2 inches wider than the Heckler fuselage. The Robart retracts are being mounted on hardwood rails glued to the underside of the fuselage. Nothing is going to be faired in or anything cosmetic. This is just a "house mouse" or working demo. The fixed tip floats are going to be screwed to the flat tips.

If this works, we would design a new fuselage and float, or buy a big float cut to our specs and widen the fuselage to match it so that when the float is retracted, it looks integrated with the fuselage. I figure we could use the SE wing and tail and make the fuselage 5" or so wide.

We have looked at mechanical retracts for the tips, but given the direction from where they actuate, the retract servo would have to be out next to the wing tip. It might be easier to just get another Robart set for the tips. It also might be necessary to jump up to .61 or .91 size to carry the extra weight. It ain't going to be a lightweight 3D plane, but float planes are heavy anyway.

I'll post some photos of the Heckler when we get the retracts in and mounted.

>>Every single float plane I have seen, full scale or RC has had the float a good bit out in front of the prop. <<
Well you DID see my ugly old Morris Jerry's Little Boy, covered with scraps from my monokote box. Bill Kaluf called it "The ugliest thing he had ever seen", God rest his soul. When you saw it, the prop was out in fron of the tips of the floats.

I don't >Advocate< having the float nose aft of the prop, but if you think about it, it makes it impossible for the prop to throw spray into the prop, too.

The floats stick out past the prop to keep the front of the floats from "submarining"... the drag of the floats in the water combined with the pull of the prop causes the plane to rock forward on the floats until the prop hits the water or the plane go's over on it's back.

Usually the floats protrude about 3" past the prop and as always the step of the float is to be 1/2" to 1" back of the CG, if the step is in the right place and the floats are not "close" to 3" past the prop.... the floats are too small for the plane.

I've seen many newbee's use floats that were too small AND mounted in the wrong place, wrong angle, even trying to get off the water with the floats at "decks a wash"... that was funny to watch.

My friends first floater was a 80" Cub with the floats just 1" ahead of the prop, took full elevator and a long run to get er up on step and he got many flights on it but landings were tricky, plane had a tendency to nose over while slowing down on the water.

The plug in wings do make a relatively compact transportation package. See SE in the back of the Mini-Cooper.

With the center of the flotation volume of the float well forward of the aircraft CG, you can see the thing floats quite nose high when static.

Early in the T/O run (still haven't got the low tip float out of the water) spray isn't a factor.

Attitude right at touchdown. Ah that was fun.

After these pix were taken I did make a 3/8 inch longer rear float strut to reduce the wing incidence relative to the main float and that did seem a bit better.

Flyer-that's what I want, but everything has to retract.

I got in the set of Robarts today and they are heavy. I may have to re-think the tip floats. It may be lighter to use a servo in each tip unless I can find some mechanical retracts that will work from the other direction. Do they still make Goldbergs?

As for how far out in front, from what I read, it is different for twin floats and for a single float and I know there can be a lot of variation.

I read that twin floats need to be 75%-85% of the fuselage length and should extend 1/3 prop length out in front of the prop.

In the same article, I read that a single float need to be the same length as the fuselage and extend 80% of the prop diameter out in front.

Virtually everything you see and read on float planes is for twin floats. There does not seem ot be much out there on a single float or many people who have experience on them.

The "How far out in front" question is de-facto addressed by making the single float 100% of the length of the fuselage, and putting the step where it is supposed to be.

WA Flyer..was that you at Shuswap last June???

Someone on RCU was building and extra 300 with a retractable single float.. as I recall he was pretty closed to finished, but I never heard if it flew or not......

Several years ago I designed high wing model which I called EASY 100. The model had 60” wingspan. Ready to fly weight with the floats was 6Lbs. The removable floats I designed started just past the prop. I did that on purpose to prevent the water spray coming of the floats and hitting the prop. On purpose I gave the floats extra volume by increasing width, so less then 1/3 of the floats are submerged. On that model I never had problem taking off or landing with this set up. The model plans were published in RCM magazine in July 1988.
From my experience with the float planes, I feel that there are several factors to be considered what will or will not work. Like the volume of the floats to support the total weight. The total weight put on the floats. The shape of the bottom of the float. The position of the step. How high the C/G is above the floats. The last but not least is the angle at which the floats sit in relation to the wing.
Laddie.