Re: Thanks a lot! - And the bad news: I got bored... again...

Hi Ed

No engineering background at all I'm afraid :) I helped my dad on occasion, he likes to work with wood and that's also where my limited mechanical knowledge comes from.
Believe it or not... I prefer flying to building (or repairing), it's just that if what I want to fly doesn't seem to exist that I try and build it myself.

You're right, the surface was quite smooth. I've modified the floats a little bit to give them a very slight V-shaped underside in hopes that this will help a bit. Someone suggested tilting the floats a bit so they gradually lift out of the water - I'll try that last, if nothing else helps.
I'll also try the ripple approach (hoping it'll be a nice flying afternoon later today - at the moment it's a tad too windy).

Hubby does fly. Sort-of. So far he has problems judging where the ground is and generally tries to land about 6 feet below ground level. The sad part is that he bought one of those electric ornithopter bird thingies, and that one was so much fun to fly... a very different kind of flying anyway. Now it's beyond repair. :(

Jenni

Ed Forsythe wrote:
Hi Jenni,
Congratulations - you've come a looong way. Do you have an engineering background? I assume the "stick to the water" experience occurred on a calm day when the surface was glassy (no ripples). You can make T.O.s much easier by taxiing in a circle (male ripples) then take off across the ripples. Helps break the suction.) That's a technique full scale seaplane pilots use. Wish you continued success and fun - hope you can get your husband involved. It will make it easier to get stuff you want if both of you want it! ;-))

"Jennifer Smith" <jennifer@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message news:V6idnYxpa9Wg7QXZnZ2dnUVZ_oudnZ2d@xxxxxxxxxxxxxx
First and foremost, thanks a lot for your guys help with retracts, and for clarifying the downwind issue.

The retracts work perfectly now, and the answer to the tail "breaking out" on downwind laps was indeed to hit the throttle - the plane then gets a bit twitchy when a gust hits it, but nothing too serious. I'm thinking of putting a gyro in as a stabilizer, that ought to take care of it I guess.

Well... and since I love my plane so much I decided to build another one, fixing the various bad design ideas I had when building the first 200% Stryker. Also, I wanted to have it land on water... (yeh, I do get weird ideas at times)

Things fixed:
- Wing attachment is now done with three hollow CF tubes in the center body part, into which I insert the wings CF rods. More difficult to align during construction, but sturdier. Fixing the wings in place is still done with collars that get screwed onto the CF rods inside the main body. I might experiment with rubber bands, but so far I don't trust them.
- Rear end considerably strengthened by putting a couple more CF rods lengthwise from the motor mounts almost all the way to the front.
- Leading wing edge reinforced with a CF rod to prevent transport damage (dents - my car is a little on the small-ish side for that hobby).
- Vertical fins cut down in half and slightly reshaped to allow for a little more prop clearance.
- Air intake inlets redesigned to guide the air over the batteries and ESC, then out right past the twin engines.

Since I wanted it to land (and takeoff) from water, I put a "drain" approximately two inches from the air intake, and routed the air flow so that water should never get into the main compartment. Out of paranoia I did however put spacers below the electronics so that even if water gets there, it _should_ run under the electronics, not through them :)

Well, floats... I had read up on all kinds of floats, but since the plane is still comparatively lightweigt despite all the added CF, I decided to build my own... Yes, yes... I am crazy. :)

I used thin 2mm depron, and glued it together with a CF rod in it. The rod sticks out on top and on bottom. I made three pieces this way, all vaguely shaped like this: |___/ - these are holding the floats. One piece additionally has a hollow CF rod in it, meant for steering later, and the CF rod does not extend through to the bottom.

The leading edge got sharpened, the rear edge just mildly blunted, in hopes to reduce drag. On the bottom of these things I glued flat-bottomed, hollow ski-shaped boxes, again hand made from depron. The lower end of the CF rod goes into each of these boxes. The rear, wing mounted ones are attached off-center, so that the CF rod glues to the inside walls of the boxes.

Steering was simple... I put a thin plastic *** under the front support, and on top of the float. Glides perfectly. In this case I glued a bit of depron to the inside of the float, right in center, and glued a thinner CF rod to it. Pushing it through the hollow tube in the front support, securing it with washer and collar and attaching a servo provided a steerable front float.

Last but not least I coated the floats with a thin coat of latex paint - which is a bit heavy. I've got no idea what else to use to waterproof them though. Someday I need to test if depron even suffers from being immersed in water, maybe it doesn't need sealing? :)

Test flight was today, just an hour ago. I'm happy with the results, it's even just fun speeding over the lake with that thing :) Props are a bit close to the water, and takeoffs are a bit challenging yet. I am not quite sure why, I attribute it to the floats. They seem to "stick" to the surface a bit.

Landing was easy. Just come in low, keep it a few inches off the water (pull up while it slows down) and when it stalls it plops down nicely. Higher speed landings work too though - I nosed one in briefly, but the shape of the floats pushed it right out and the air intakes were still bone dry. The tube of the front float seems to suck water up, but it wasn't more than a drip - I'll ignore it for the time being.

You know the best part? It was all dirt cheap to build (if you ignore the electronics - and the only things I bought new was servos, ESC and reciever).


What a fun hobby.

Jenni


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