I have a Kadet SR (biy) that I'm thinking of equipping with floats.It seems to be a rather popular airframe to convert,but I dont ever seem to see size/or source of the floats. I've been looking at the sig website,and they have 2 arf float sets and a float kit. They seem to go by airframe weight,not fuse length or wingspan.If I went only by weight,the 40 size floats would be fine.But on other sources they go by fuse length. The Kadet sr. is close in size to the 1/4 scale cub,but much lighter,and the recommended floats for that say good for models 16-25 lbs.
My thoughts are that the smaller floats,though able to handle the weight,would be pitch sensitive.And the bigger floats would be a better choice as it would be more stable,and the airframe can handle the extra weight of the bigger float.
Am I wrong?

Don't worry about the weight. Get the float size by the length of your plane. Foam floats are pretty light.

Go to these guys- great foam floats. [link=http://www.seaplanesupply.com/]Seaplane Supply[/link]

or these guys. [link=http://www.planefunfloats.com/]Plane Fun Floats[/link]

I've used, and am using, both types.

Do what Ed says. He is smarter than the next three people you know, combined.

Also possible sources for floats: Sea Commander and Slocan Floats. DO NOT use built up plywood floats as they are much too large and much too heavy.

You will find that a Kadet Senior is a fantabulous floatplane. I have seen them fly with a .45 2C thru a .90 4C. My son flies one with a .70 4C Magnum and it is about as ideal as it gets.

PlaneFun Floats offers "narrow" floats to address the light weight of the Ksr. I am sure that Seaplane Supplyhas an appropriate option.

It looks like you have done your homework well. In doing so, you have stumbled upon the lack of commercially available floats in the right size for your plane, Selecting floats should be like selecting shoes. First find the proper length, then the proper width. The proper length will give you the water handling characteristics you want and the proper width will give you the bouyancy you need to properly float the plane. Our problem is most float suppliers only make one width which in many cases is too wide (more floatation than is required) Don't let this discourage you. If you strictly adhere to float selection guidelines you may end up not float flying at all. If you want to get into the water you may have to bend a little, I've seen the Kadet Senior fly on 42" floats and on 34" floats with equal success. I would never have suggested 34" floats but I saw the results.

I would suggest around 42" floats for the Kadet Sr. but if you go with the wood kit floats which will work, they will be a bit too wide and too heavy for optimum results. I use Plane Fun Floats 42" Slim floats on my Senior and it is the plane I love flying the most. I am the maker of the Plane Fun Floats and I'm not trying to sell you a pair of floats. I'm just trying to share with you my experiences as did Jim and ED. I'm sure Mark at Seaplane Supply has an equally suitable set of floats for the Kadet and he is a great guy to work with.

I hope this helped.........Ralph

First let me apologize that I MEANT to list Plane Fun Floats in my last message, but I had a "Senior Moment". I have now corrected.

Some of the great flying experiences I ever had, happened with Kadet Seniors. Three or four of us would play "Pass the transmitter" with a Senior, and whe it was your turn, the game was to circle the pattern and to perform the slickest landing possible. WOW! I improved my technique SO much doing that!




Ralph was right about the proper float size for a KSr being 42". That is what these planes have. I was the foam-cutter dude for that club when I lived there.

I mentioned alternate suppliers: SeaCommander Floats have a line of foam floats, and they have been around a long time. Slocan floats has something of a cult following in the PAC NW. Neither of those suppliers, to my knowledge, participates in this forum. Meanwhile, Ralph and Mark are right here with unbiased advice whenever somebody needs them.

Jim, that Middle pic is upside down,,, I think

HeeHee!
It was such a pretty shot and the water was so glassy that when I put it in the club newsletter, everybody missed that it was inverted. 

Hello,
Need some help. I have a Goldberg anniversary edition Cub, and I need to decide weather to use the Goldberg floats (kit) or can I use the Great Planes ready built 60 size fiberglass floats? Any suggestions out there. Will the GP floats adapt to the Goldberg Cub? Anything I should be aware of? Thanks......

Also any suggestions on an engine - OS 55 or OS 61 ? Thanks.........

Step up shouldn't be much different between the 2,,

IMO though, those are the worse, non-scale like, looking Fiberglass float out there., I'd build/glass/paint a wood set before I'd use those

No and No.
Read earlier in the thread for references to PlaneFun Floats or Seaplane supply. Truly these floats are superior to the ones you referenced.

These guys make nothing BUTfloats and they are D**N good at it. The "accessory" floats are offered be grudgingly by the kit manufacturers, made of materials on hand, on equipent on hand. .
Ihave BTDT.The foam-core floats let your plane fly much better.

I have the 40 goldburg cup on the goldberg floats with a saito 56, and shes a bute! flys very scale like. i ditched they're water rudder rigging and made dual rudders with pull pull cables more like a real float plane, and the wires that came in the kit needed some slight adjusting to get the floats flat, and they aren't scale at all. but ive had great sucess with they're floats, and they look great too. only thing i would add is a steel wire or something in the keel at the step to toughen the area that sits on the ground a little bit. i also painted the floats with polyesther resin and then aluminum paint. also make sure the blind nuts in the floats are held in really well, it sucks if they fall out.

It's worse when they come loose with the bolt jambed, I never use blind nuts in an area I can't get pliers on them,, I'd tap ply or hardwood,, also, blind nut and anything but stainess has a tendence to rust up in floats

Hello Jim Casey,

I have a GP BIG STIK 60 ARF to put together and I will be doing a tailwheel mod during contruction. I also will be adding reinforcement for a rear main for floats. I have a new set of sig floats (41.5" length) and would like to use them on the big stik. I know in a previous thread in 2002 you mentioned the float length for this plane should be 45" nominal. How critical is that difference?
Also, the main gear width in arf kit seems to be less than 25% of the wing span. Before I buy a matching landing gear, how critical is that to the overall success of the float plane?


Jim, thanks for your help in this and any other float topics for this plane.

Jim Clousing

All the float sizing "rules" are guidelines. They have been found by experience to work almost every time.
That being said, Ihave used floats on a light plane that were probably 6" shorter than the guideline indicated. They worked. Alot of the reason for having floats' noses in front of the prop is that it protects the prop when you are beaching. Can the plane nose over?Yeah. Ithink I had that happen once in close to 20 yrs of flying floats.
Float spacing 25% of span:A good compromise between tippiness (resistance to blowing over sideways) and straight takeoff runs. They don't squeeze the floats closer together on clipped-wing cubs. Planes with a lot of dihedral are tippier.

You can cheat one of the float guidelines, maybe two, but when you cheat ALLthe guidelines you're kinda asking for disappointing performance.

But let's review:
GPBig Stik 60: nice plane. Suggest you build it with a flat wing (Take out the dihedral). Stiks have flat-bottom fuselages. If you put on 2 sets of identical landing gear, the float incidence comes out to zero. When I put identical landing gear legs on a H9Super Stik, it was hard to get it to take off. A 3/8 shim in the front gear legs, or a little bit of flaperon will let you deal with that.

Floats too small. The only thing you will probably notice as an annoying shortcoming is pitch instability in the water. Your prop will probably pick up spray when you taxi thru waves. You may damage the prop or the dock when you taxi up to it, or the prop may hit the beach. If they don't have enough floatation, you may find that you push a lot of water up over the Bow. Taxi with full UPelevator. Use a Master Airscrew Black prop. They are the most durable I know.

Sig Floats: (Take this paragraph with a grain of salt. Iam opinionated)
From their website: <font size="2" face="arial">"Built from lite-ply and balsa and pre-covered in SIG AeroKote&reg; using a proven watertight seam overlap technique, the floats are light, strong and perform beautifully. The .40 Class Floats are ideal for aircraft up to 7 lbs (3175 g) </font>"
I doubt if a BigStik 60 weighs less than 7 pounds-especially if weighed after the plywood floats are installed.
Ihave used lite-ply in floatplane hulls. It has approximately the same water resistance as Saltines. AND it grows mold even faster. In my experience, once it got wet it turned into a mildewy paste in a week. If you are really careful not to get the covering on the bottom scratched, they can last a long time. I love SIG and recommend some of their planes as Ideal Floatplanes. Idon't like ANYBODY's plywood floats. Unless you KNOWthat the floats were sealed internally and externally before being covered. be cautious. And Ply floats are going to be heavier than other types. Choices1)try the floats. See how they work. you could be lucky. (2)Get a good pair of lightweight foam-cored floats from Plane Fun or Seaplane supply. They'll be the right size and they'll weigh half as much. You seal them before you cover them or before you paint them (Water-Based Polyurethane varnish works beautifully as a sealant. Cheap, nontoxic, everything-proof after it dries, does not attack foam with its fumes. WBPUalso works well to bond glass cloth to the float to stregthen them )

Jim Casey

Thanks for your advice. The sig floats I have are somewhat different. They seem to be all fiber-glassed and they were a discounted price on sig's website because they found out the paint or sealer was not fuelproof. ( needs to be redone) They were discounted from about 100 to 50 for the pair. Specs: Sig's Smoothfloats(TM)
33.3 ounces per set
41 3/4 inches
for .40 sized planes weigh up to 10.5 #
I know the foam floats are lighter and better but I have these to use for now...........
I am also putting together a WM Skyraider Mach 1 trainer right now. Wanted to replace my first trainer as it crashed on a very windy day a year and a half ago. Fuse length 53" Wing span 66.5" Flying weight 5.5# .40 -.46 2 stroke recommended. Maybe this would be a better float plane for these floats. It has very little dihedral but I cannot remove now as the wing is epoxied together. Semi symmetrical wings. Planning on using a new TT pro .46 for power but do you think that would be enough for the extra float weight? I do have a new 0S 55 ax but wanted to use that for something else a little more power worthy. I was only planning on a new OS .61 fx for the Big Stik 60 float plane maybe not enough?

Thanks for you help,

Jim Clousing

My Sincere apologies Jim. I misread your post and thought you were putting on a smaller motor. Reading it again I see that you referred to another plane. I am Redfaced here.....
Ihave corrected my response.

Floats have more frontal area than wheels, but they are more streamlined, too. Drag is not increased as much as some think. Trainers with flat-bottom airfoils actually seem to be MORE aerobatic with floats.
Some seem to think that adding floats means you need to upsize your engine to a turbo-cosworth, but Ihave not found that true.



Tower says the Big Stik .60 "REQUIRES: .60-.91 2-stroke or .91-1.20 4-stroke Engine 4 Channel Radio minimum 5 Standard Servos Y-harness Building and field equipment</p>

COMMENTS: This kit has a fully symmetrical wing held on with the included nylon wing bolts. This plane can be built as a taildragger or with a tricycle landing gear."

An OS.61 will fly it. You might find that it climbs/accelerates/slows for spot landings better with a 14-4 than with a 12-6.

I'd probably grab a .90 4-stroke, and use an onboard glow lighter for a more reliable slow idle. That's what I used in my telemaster, and it's in a BTEFlyin'King now. </p>

Hi Jim Casey,

No apologies necessary...................thanks for the help!

I have decided to go ahead and mount the 41.5" floats on the World Models Skyraider Mach I. The fuse length is 53" and the 41.5" floats fall in the that 80% range. However, I read some information the the fuse length is figured from the rudder hinge to the prop backing plate which is about 49" on this plane. Do you think these floats could work out? They might be a couple inches too long. Better than too short?? With the step at the CG the front of the floats extend past the prop about 3.5". The engine falls in the rec. size of .40-.46 a OS46AX. The strut gear width falls into 25% of the wing width. I installed ply reinforcement at both gear mounting sites.

But I wanted to run this by you first....................

Thanks,

Jim Clousing

Like Hand-grenades and horseshoes, close is good for Float sizing. 
Remember that the weight is AT LEAST proportional to the square of the length if not the cube.