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scale only 4 me 03-30-2010 08:56 PM

A really small float plane build thread
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OK, I've never done a build thread but what the heck here goes

The Subject? a Nakajima A6M2-N,, Yes a Rufe a real small Rufe. Actually it will be a kit bash from a GSW Zero kit, with scratch built floats

I ordered the Kit and flight pack a few days ago and the FedEx Babe dropped it off today, the box looked like it was packaged well but upon removing the parts for inspection I noticed a little damage on the fuselage and the sticker sheet looks real bad,, I'll be emailing the vendor to see what he says about replacing the decal/sticker sheet,, the small dents in the fuselage halves I can live with since I'll most likely repaint anyway,, we'll see.

I plan to built the main and tip floats so the are removable so I can fly the plane at the park or where ever too,, we have a nice little fishing pond in town and a small electric float plane should fit in nicely.

Stay tuned,,, or not ;)

MinnFlyer 03-30-2010 09:51 PM

RE: A really small float plane build thread
I hope you don't mind, but I changed your images to attachments. It makes them much easier to see.

Just click the reply button above and to the left of the Fast Reply box and click "Click here to upload images and Files" to upload the pictures.

Looking forward to the build!

scale only 4 me 03-30-2010 10:27 PM

RE: A really small float plane build thread
I know how,, I just took the photbucket short cut,, I'll used the attach in the future,, it does make for a cleaner looking post,,


scale only 4 me 04-09-2010 05:49 AM

RE: A really small float plane build thread
I've been sitting on the kit waiting for a reply from the Ebay seller I bought the kit from, a couple emails and no reply after 8 days, debating if this calls for negative or just fair feedback, most likely the damage isn't his fault,, but the kit is obviously very old stock based on the condition of the decal sheet. Looking back on his feedback he has a history of not getting back to people when there is a problem, My bad for not researching the feedback before I pulled the trigger,, No big deal really

Annyway I'll start assembly this weekend

Problem solving for the water config?

1- Water steering,
I've given it a some thought and have (Like Da Vinci) designed in my mind a pull-pull system using monofilament and plastic or aluminum tubing as a housing. Ill run the mono through the tubing to the aileron servo(s) and use rudder mixing so when I give rudder input the water rudder will drive from the aileron servo(s)

2-Landing Speed,
Knowing that one of the the flight characteristics of these little planes is they land at a relatively fast speed which is not great for a water plane. Flaps solve that issue most time, but since the plane is so small I've decided I'll use flaperon control, 2 Aileron servos. To keep the plane as light as possible I'll not use an air rudder servo, just have a fixed vertical, I can always add later if needed

3 Attaching tip floats,
I'm thinking using the same plstic gear plates that the main gear would use, but those most likely will not be strong enough alone to with stand the torque of a single attach point, I may have to use the Monofilament again as guy wires, I have an idea how to make that work

Problem still to solve, I'm Welcoming Ideas
1- Waterproofing esc/radio gear
Typically I put the radio rx in a bags. A question I have being new to Elec. would putting the ESC in a plastic bag be bad for cooling purposes? or is that something I don't need to worry about with this small a plane?


foodstick 04-09-2010 03:57 PM

RE: A really small float plane build thread
I am looking forward to seeing this! The Rufe is an unique warplane. hopefully this project works well.

scale only 4 me 04-13-2010 10:47 PM

RE: A really small float plane build thread
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Well only time will tell if it does work well, the other I built flew great, but it was bigger,,

Pics in my gallery and video here

Weather was too nice over the weekend to play in the basement, but last night I started the airframe assembly, I won't post pics of that, but tonight I did get a chance to start the Tip float attach point.

I used the stock landing gear block and wire, it took a little patients to cut the foam without making too much a hack job out of it.
I narrowed the depth of the block so I wouldn't have to go so deep in the wing, I'll epoxy them in, the wire will some how get sandwiched inside the foam tip float. and be removable with the 2 stock screws. I'm thinking this block/wire will be plenty strong enough after all

Tomorrow I hope to start shaping the main and tip floats

scale only 4 me 04-13-2010 11:26 PM

RE: A really small float plane build thread
while hunting color schemes, I ran across this which looks to be a Japanese YouTube type site

Seams I'm not the first nut to try this (not like it thought I was)

After seeing this one I think I'll get my RC boat ready too

Edit,, those links worked last night??

same videos can be found here

scale only 4 me 04-14-2010 10:50 PM

RE: A really small float plane build thread
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Worked on the float,

Based on my math, the main float is 22.5" long,, about 3"x3" at the thickest point before shaping. The plans I worked from are RCM Rufe conversion for the Top Flight Zero, those are 41" long, so I had to subtract 45% from every measurement. I first I transferred the profile (side view) measurements and shape onto the block,cut the foam 3x3x22.5 on my table saw,, then, cut the after-body with my bandsaw and rough shaped the nose with my disk sander. I then plunge cut a 1/8" wide slot about 2" deep with the table saw. The main float attach piece, 1/8 light ply, will get glued into that slot. Then I will add foam and shape.

scale only 4 me 04-14-2010 11:14 PM

RE: A really small float plane build thread
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Next the tip floats

I cut 2x2x6" blocks and was able to blow up a 3-view picture to get the shape, I rough shaped with the disk sander as well.

Now on to attaching to the wire?
I decide to solder a wheel collar to a piece of flat brass and then that go screwed to plastic tube (the inner pieces of Nyrod),, I've used this method to attach to foam before and when you epoxy those in it's very strong. The hard part is tapping the nyrod to accept the wood screw, I find warming the screw with a cigarette lighter helps a lot (no I don't smoke,, but have one in my field box)

I may need to re bend some new wire pieces as the stock landing gear wire may be too short (one broke at the bend when I tried to straighten the 90 deg. bend) Also I still need to clean up the brass mount prior to painting. I'm not going crazy with the fit and finish on this, so forgive the sloppiness.

I'm using the wheel collars, so I can adjust the tip float height, once I fine tune that I'll wrap the wire with balsa or maybe a flat straw???

A quick mock up to get the idea of what it will look like


scale only 4 me 04-15-2010 10:07 PM

RE: A really small float plane build thread
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I did find a little time to shape the tip floats and work on the front main attach point.

The 12" disk sander I bought last year came in real hand on this project,, I couldn't imagine shaping these all by hand

The zero uses a bamboo dowel that acts as a spar so the wing is slotted for it, I made a lite-ply piece that will fit in the slot and cross join the main float brace. I then made a couple straps out of left over control horn backing pieces, used the nyrod in the foam method again,, the epoxy is gluing as I type.

Tomorrow I'll work on the rear braces and do some finial shaping of the main float and front brace

scale only 4 me 04-16-2010 10:30 AM

RE: A really small float plane build thread
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You're all laughing at me huh,,, good ;)

The rain gave me a little time this morning to start the rear main float braces. They are made with some 3/8" streamline tubing I picked up the other day. Bolts comes through the top of the wing,, I just tapped the aluminum to receive the bolt,, Simple is good. The hardest part was making the holes straight in the foam float without making the holes too big. They will just get epoxied in once the float is finish being shaped.

I'm liking the proportions so far :D

scale only 4 me 04-16-2010 08:38 PM

RE: A really small float plane build thread
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Worked on shaping the main float, drilled a few lightening hole and glued up the foam to add the shape to the front float support. It came out OK, but I have to keep reminding myself this isn't a scale contest winner, the foam is tough to sand to a real smooth finish.

I made a water rudder and ran a plastic tube through the front support, My idea was to run fishing line through the tube and connect to the aileron torque rods to control the water rudder.. I'm hoping the pull pull will work well, the fall back plan is to mount a servo in the float,

Everything is gluing up as I type,, I'll do more over the weekend, A few more hours of rigging and painting she will be ready for the water

scale only 4 me 04-18-2010 10:39 PM

RE: A really small float plane build thread
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Airframe is ready to fly, I haven't hooked up the water rudder yet, that is the last thing before it's ready to take off from the water
I was curious so I weighed the float (before painting) they only weigh 2.5 oz. That suprized me,, Figure another .5 oz. with paint only adding 3oz. is great
I'm going to take it to the pond and see how it sits in the water to see if I need to make longer wires for the tip floats. More than likely I'll madien it tomorrow without the floats to set the trims

I decided to go with the all INJ Grey scheme,, The paint I used just happens to be the paint I used for my garage, it's amazingly close to INJ Grey

More tomorrow

scale only 4 me 04-19-2010 09:12 AM

RE: A really small float plane build thread
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Well the fishing line through the tube didn't work well at all,, too much friction , so I drilled through the wing and went straight from the servo horns to the water rudder horns, these seems to work just fine.

Basically I just tied a knot and ran the line through the water rudder control horns, the line runs straight as possible to the horns, where I have it going through the outside hole in the servo horns, then it wraps around the servo horn screw and that screw secures the adjustment. Simple but seems to hold and work well

I'm hitting the water/park later today,,, Maybe Hitting is a bad choice of words ;)

chistech 04-19-2010 09:36 AM

RE: A really small float plane build thread
Great job. I'm watching this as my buddy that is helping me with the kingfisher will be building a Royal "Rufe" over this coming winter. I'm sure he will enjoy looking at your thread. Good luck with the maiden.

andybenton 04-19-2010 03:20 PM

RE: A really small float plane build thread
i allways wanted a sea plane, i just never knew where to start, but awsome looking build. keep it coming

scale only 4 me 04-19-2010 07:17 PM

RE: A really small float plane build thread
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Thanks for the kind words,,

Well it looks good on the water,
I think the tip float heights will be OK, The bad news id the GWS receiver didn't range check at all, I can only get about 8-10' away With the antennae out??
I'm not sure what the problem is there
This kinda suck because the Ebay seller never got back to me when I emailed him about the damage durring shipping, I'll have to Email GWS directly and see if they can help

I'll switch to a Hitec receiver I have and try again,, maybe tomorrow

scale only 4 me 04-21-2010 07:01 PM

RE: A really small float plane build thread
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I know you're all on pins and needles waiting for that Maiden Flight Video,, ;)
I'm going to hit the lake tomorrow with my wife.

I did get me RC boat going and build a retrieval buoy thingy,,,
Of course I'll never need it because I'm just that good :D

chistech 04-21-2010 09:18 PM

RE: A really small float plane build thread
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Thought I'd post a picture of my friend's (who passed away) retrieval boat. He too made a buoy to snag his plane. A large 13 1/2' span PBM. The boat is powered by a geared prop drive with two 12 volt gel cell batteries. The hull is a custom (I believe) fiberglass hull. The prop and rudder are enclosed in a heavy screen weed guard. I haven't seen it run but I might end up running it to try it. It is one of the many items in my friend's collection that is for sale. I will start posting more items here on RCU soon.

chistech 04-21-2010 09:38 PM

RE: A really small float plane build thread
Sorry, I forgot to say, "get that thing flying". :D Good luck on the maiden. I am watching this close as I am presently negotiating a deal for a Kyosho Zero complete with a spare, new wing. I can make it both for land and float flying. It would be the "bomb"

scale only 4 me 04-22-2010 04:05 PM

RE: A really small float plane build thread

Several things will have to be modified before it flys off he water,, mostly minor things
I did maiden without the floats after the video was shot,,,,,
I'll elaborate later

scale only 4 me 04-22-2010 08:14 PM

RE: A really small float plane build thread
Yes there was a taxi test #1,,it was also a failure,, I flipped it and well, nothing was hurt, all the electronics survived fine

Several things I did noticed other than the fact this motor combo won't cut it.

Painting it with flat paint was a mistake, as soon as you put it in the water the paint sucks up the water and increases the weight,, this might be why it won't come up on step,, but I still think it will need more power. I'll have to sand off the flat wall paint and repaint with some latex enamel,, The stickers are peeling from the water anyway so no loss, I'll have to paint the meatballs next time.

Floats seem to work OK, I'm pretty sure if I was able to get it on step quick enough I could leave them be. But it was just tipping a little to much past vertical for my liking,, I think 1/4 on each side would do it. I've had the best luck when it is set up that when slow taxing (not on step), when one tip lifts out, the other is just touching. You don't want a see saw effect, that will make it lean too much to one side and water loop too easy. I'll have to bend a new wire for the one side.

My water retrieval buoy thing needed a little work,, I tried using it when the plane was floating (off camera),, the fishing line just went under the floats,, I'm make some adjustments

Other wise the Floats off hand launch maiden went fine,,, other than the fact my wife had never launched a plane and she tossed it like she was letting go of a balloon,, Luckily I had a little head wind,,, It was way off trim in the elevator,,, once I got it trimmed if flew fine,,,, gutless, but fine

Anyone have a suggestion on a good brushless/ESC?battery combo,,, I'm all ears

scale only 4 me 04-25-2010 10:20 PM

RE: A really small float plane build thread
Well, being a electric newb,,and after doing a little reserach I come to find the Ebay Vendor (Tom's RC Simulator aka tti_7), who I'll never buy from again,, included the wrong voltage battery pack, he sent a 7 cell 8.4v NiMH pack, not a 8 cell 9.6 pack, that extra voltage might very well make the difference.

I'm going to order a coupe small 3s lipos and give it another try before I do anything else,,

more later

scale only 4 me 05-05-2010 08:40 AM

RE: A really small float plane build thread
Just to follow up,

I did get a 3s lipo and it seemed when I hooked it up it would be plenty, Monday I took it to the pond and the servos just buzzed and locked. After doing a little tinkering I come to believe the ESC has died. A real weird problem as it's putting out 5 volts like it should, but it making my FASST Rx Lock up. When I try a regular Rx, it still does the same servo buzzing. When I bypass the esc everything works fine with either Rx

I'm not sure if when I flipped it it did get a little wet or the higher voltage pack was the problem, but I'll need to get a 3s lipo compatible ESc at the minimum, I more than likely will just get a brushless combo compatible with 3s lipos and give it another try.

I'm not impressed with the GWS electronics, The Rx was DOA, works only if the Tx antenna is right on top of the Rx... and now the ESC is dead too (maybe my fault?)

Oh well,, stay tuned, I'm not giving up yet

scale only 4 me 06-24-2010 08:37 AM

RE: A really small float plane build thread
I can't believe it's been almost 2 months since I played with this, but it took about 4 weeks to get my order and I'd been messing with my Extra 300, + doing househod projects.
But, The Ruff is finally rigged with a brushless and proper ESC, I'm heading to the pond later today, Will have more Video,, good or bad ;)

I did take it out but the wind was up so no flight atempts,, I'll try again soon

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