Bush Tandem!

[Monte.C]

Thanks @synjin, I like talking shop.
I looked for your DL-57, found the plans you posted on one of the threads. Do you have photos or vid?
I love the idea of elevons just on the rear wing. It's an elegant solution. At the other end of the spectrum is mixing all four servos together.

Well I already have the servo cutouts under the wings, and the control surfaces cut out as well. I'm thinking the safest approach is to follow the plan, put elevators @ rear wing and ailerons @ front. When it proves to be a fun flier I can disable or remove the front ones and mix the rear.

Yeah I need to get fluid with rudder use.
The wing positions are dictating control surface placement. It took me a moment to figure out the elevator wants to be as far from the pitch axis as possible, so the rear wing is where they need to be - that's significantly farther that the trailing edge of the front wing.

The front wing is about 80% of the rear wing in area. The upper wing dihedral is more than the anhedral of the lower wing. Also of course the center of lift sits above the CG. Between those three facts it I think it has to have a positive self-righting tendency, but I have no idea how much. Even if it flies as if it had just one dead-level wing it'll be controllable and I'll be happy.

Scratchbuilding is one thing - I'm really sure about the two other planes I've designed/flown and the ones on the board, but this one is scaring me, it's seems like such an unknown!

 

[Timmy]

I can hardly believe this crazy thing is happening.

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It looks weird in a good way. I don't know how to explain it.....It just looks really cool.

 

[Monte.C]

It looks weird in a good way. I don't know how to explain it.....It just looks really cool.

That sounds good to me - I still can't figure it out!

(If it doesn't fly well then it doesn't matter how it looks!)

 

[Monte.C]

I think it's sort of like a flying wing with a central tailfin [and another wing in front of the first one].

 

[Timmy]

updates?

 

[Monte.C]

updates?

Not really, been so busy with stuff...
But the weekend's coming.

 

[leaded50]

Welcome to Monte's paint shop. How do you spell "frustration"? No matter what I do, the good detailing tape brings up some paint with it. It might be time to switch to simple line graphics. But it's such a crippling concept to not be able to do curves when I can do curves.

Stick to my plane painter's mantra, "It'll look good in the air. It'll look good in the air."

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If ground is to slippery,it comes easier loose the topcoat paint. The way that help, is to try get mask tape off before top paint dryes. Or at least as fast as possible.
Blue paint maskingtape will not stick as hard as the standard "yellow" one, even if that not help on lifting of paint edges.

 

[Monte.C]

If ground is to slippery,it comes easier loose the topcoat paint. The way that help, is to try get mask tape off before top paint dryes. Or at least as fast as possible.
Blue paint maskingtape will not stick as hard as the standard "yellow" one, even if that not help on lifting of paint edges.

Yes and yes.
The silicon-impregnated surface of the brown FB doesn't like to hold the paint - I haven't had this trouble with DTFB. It's fine except where I want to tape off a second color over the first color. I'm using three top quality tapes. The blue 3M masking tape doesn't lift the paint, nor does this other tape I have. It's the 3M vinyl detailing tape that lifts the first coat when you use it to tape off a second color.

I thought I was the only one who knows to remove the tape right away to get clean edges. Good job @leaded50.
Yes I've tried running it over my jeans. I've tried a lot of things.
I might try building another plane from DTFB if I want to tape two colors. Shame to have to do that. I bet this was the biggest incentive for FT to create the maker foam.

 

[leaded50]

@Monte.C , ive been working with paint.. at MC, cars, paintbrush, lettering , striping, eg in many years.. i learned fast

But, im more interesting in what you feel by flying a tandemwing, what experience you get

 

[Monte.C]

But, im more interesting in what you feel by flying a tandemwing, what experience you get

Hey me too. Especially with this rather extreme wing geometry. Soon...

 

[leaded50]

Hey me too. Especially with this rather extreme wing geometry. Soon...

I need try get maiden at both the Payen and DeLanne builds of mine, but last times, its just rain and wind, or ive been to sick to try fly... Perhaps should made a tandemwing seaplane, had fit weather best .

 

[Monte.C]

Perhaps should made a tandemwing seaplane, had fit weather best .

Oh no @leaded50 - A tandem seaplane? LOL That's crazier than a bush tandem!

My hatch:


The fuselage wants a doubler for strength and to provide a shelf for the hatch to rest on. I try to build slender & light for the small size of my planes - up to about 30" WS. So I've been using strips of basswood. In this case the top of the fuse isn't level, so the basswood is cut at the front to serve as a level rail to align the power pod against.

 

[Monte.C]

My landing gear:
I've been hesitant to post this one because there'll be a bunch of people who'll right away say "that won't work" for various reasons. We'll just have to put Gorilla Glue & foamboard to the test.

The screw that holds down the servo arm is driven through the bottom plate to a wood strip glued to the interior of the wing.

What looks like a straw is... a straw. I was wishing I had one of those paper cocktail straws, so I made my own with brown paper & CA. It's hard as a rock.

The groove for the wire is the space between two pieces of plywood (the black pieces). The servo horns are very firmly mounted. You can just turn them with a little bit of force. No need to ever turn the screw.

 

[Monte.C]

I like to use these subway cards for the power pod mount. They're a lot thinner than a credit card, but there's no way the bamboo skewers will tear them - the power pod will crumple long before that could ever happen.



I use a layer of packing tape on the power pod just like the FT crew does in their videos. I tightly wrap one piece on the front and both sides, then trim the edges. With the power pod tight against the fuselage sides (and subway cards) this packing tape won't tear under any normal forward thrust conditions. (Only when you try to fly into the ground.) And with these A-size motors I've been using, 1806-2280, this minimalist power pod is all that's needed.

I do have one 2205-2300 F-size motor, but all the planes I've built & flown so far have had loads of power with the 1806.

 

[Vimana89]

Had you considered elevons on the rear wings?

THIS is an efficient way to run a tandem design, pretty much no matter what other variables you got goin'. I use elevons and rudder 4ch control on my tandems. The elevons on the rear wings will give you all the leverage you need in elevator function, and be big enough to giver you the roll authority you want at the same time without needing ailerons because you've got a full size wing in the back and not just a tail plane.

 

[Monte.C]

I've made a monster. I'm afraid to fly it.
I'm sure it'll be every bit as squirrely on the runway as the Rutan Quickie is known for.

 

[Monte.C]

THIS is an efficient way to run a tandem design, pretty much no matter what other variables you got goin'. I use elevons and rudder 4ch control on my tandems. The elevons on the rear wings will give you all the leverage you need in elevator function, and be big enough to giver you the roll authority you want at the same time without needing ailerons because you've got a full size wing in the back and not just a tail plane.

Good. I already had the control surfaces cut when I heard that the first time so I went ahead this way. It's a safe direction to go anyway. Then if it flies well I can remove the front servos.

 

[Monte.C]

Oh I just figured out I won't be able to take it out to the field on my bike. If I strap it to my backpack the wings will look like fairy wings, and people will think I'm a fairy.

Nope.

 

[Hondo76251]

If I strap it to my backpack the wings will look like fairy wings, and people will think I'm a fairy.

Ive heard thats one of the 57 new genders, i think you'll be in the clear! 🤣

Im sure interested to see how that wild looking thing flies!

 

[Monte.C]

Ive heard thats one of the 57 new genders, i think you'll be in the clear! 🤣

Im sure interested to see how that wild looking thing flies!

The last thing I want to be is PC, or one of the new fashionable genders of the season.

Hey I'm serious about being afraid of the thing. Most nervous I've ever been with a maiden flight. Everything logical says it should fly great. Somebody hold my hand!