I am thinking about building a twin boom pusher airframe - for use as a platform for aerial photography. What I have in mind is something like the "Pegasus I", made by kd7ost, see http://www.rcgroups.com/forums/showthread.php?t=792387 , but simpler.

I have been in contact with kd7ost, and learnt that "Unfortunately this airframe is a one off design. There were no plans made that have any detail. I designed it but just made it up as I went along. I did an "after the fact" thread on it here."

My idea about the airframe is that it should be:

• quick and easy to build,

• robust,

• able to carry about 0.5 - 1 kg / (1-2 pounds) of payload,

• flight-time: up to two hours at 50 km/h (30 mph),

• modular fuselage, (detachable compartments for engine/fuel, electronics/autopilot/sensors, and payload),

• 3-pieced detachable wing, (ailerons/servo in the middle section),

• possibly with v-tail,

• be easy to disassemble/assemble,

• fit in a normal suitecase for safe and easy transport,

Unfortenatly, I have previously only built some boats and a ARF airplane. Therefore, I will need help with this one. If anyone is interested in participating, I suggest we make this a "open source" - project, where the goal is to create drawings, a bill of materials, and a manual for how to build the plane. I use AutoCad for drawing, and suggest dwg/dxf as the drawing-format, which also makes it possible to scale drawings to suite induvidual needs. (There are freeware alternatives to AutoCad available, e.g. ProgeCad LT- for those whitout access to AutoCad).

http://www.progesoft.com/ (ProgeSoft homepage)
http://www.rocketdownload.com/progra...cad-90298.html (downloads)
http://www.caddit.net/progecad/tutorial/ (tutorial)

If there is interest for this project, I suppose it is just to start to establish a general layout and basic parametres for the configuration.

brakar

yer gonna have trouble with the fitting in a suitcase part, but I will be following along this thread to see how you fare.
PS you got 1.5 kg payload twice

I don't have much to offer, except that I recently finished and flew a foam twin boom pusher. It has very stable, predictable flight characteristics and would make a good camera platform.

brakar,

You might want to check out Philippe Techer's plan for Big Brother at http://www.extremeaerotech.com/en/plans/gliders.php (third plan on the page). If you scaled it up, it might fit most of your requirements except for being a quick build

Alan

Thanks for comments so far;
- jstntmcdrmtt: I have redused the payload requierments ...
- Will Rock: really nice build, looks simple and with few parts
- Al Offt: the Big Brother was the one twin boom pusher I also found - before starting this thread

Hving done a bit of reading, http://adamone.rchomepage.com/design.htm, I have come up with a few initial thoughts for the configurations:

Due to the requirement "fit in a normal suitecase for safe and easy transport", I have reduced the targeted payload from 1-1.5kg to 0,5-1 kg. I think this should be possible to obtain with an airframe with target total weight of maximum 3.5kg, (2.5-3kg + payload).

To achieve the "quick and easy to build" requirement, I consider a clark-Y wing. With recommended wingloading (15-20 oz/sq ft = 4.5-6kg/m2) this would mean 58-78 dm2 wing area, e.g. about 70" x 13"

Any comments so far?

brakar

There are some other twin booms out there one is based on a skymaster see this page, http://plans.rcmodell.hu/plansport.html delleat the front motor for payload and fit an electric pusher http://www.rcgroups.com/forums/showt...ght=M55+mystic , better still base it on an ultralight twin boom.
More links to be added I added some waterplane possible platforms http://www.rcgroups.com/forums/showthread.php?t=1017965 and some time ago in UAVs there was a thread where I threw in a lot of possible twin boom platforms. http://www.rcgroups.com/forums/showt...=819918&page=2 http://www.rcgroups.com/forums/showthread.php?t=682477 http://www.rcgroups.com/forums/showthread.php?t=665852 http://www.rcgroups.com/forums/showthread.php?t=222959
http://www.rcgroups.com/forums/showt...ic#post7256092 google a Hawker Siddley Argosy and you will see the sort of layout your looking for.

http://www.acesim.com/rc/polly/polly.html

http://www.rcgroups.com/forums/showt...ght=M55+mystic
http://www.rcgroups.com/forums/showt...ght=M55+mystic

Re the fit in a suitcase.

I scratch built a Lazy Bee for fun flying and AP work. Made the wings two piece, all flying horizontal stab that just plugs in, and all so that it would fit in a nice small box.

Arrrrrg!.............Do you realize just how darn big a transmitter is.

No matter how I tried to configure a layout, the Tx was the major problem, and a DX7's antenna doesn't help either.

Good luck with the project, but factor in all the ancillary bit and pieces for that suitcase, (especially that darn Tx).

I suggest you do a search in the "Foamies-Scratchbuilt" forum for the Shadow 200 thread. It's a scalelike model of an current US military recon drone. The designer's CAD work is outstanding. I'm building a larger 72" span version based upon his plans (but using different materials and techniques) for use as an aerial video platform.

We expect to be moving to downtown Chicago soon. We will be without a car, depending upon a bicycle with trailer and/or public transportation. So, I too will need mine to disassemble and fit into some type of carrier, albeit larger than a standard suitcase. I think that will have to be determined and obtained prior to doing any serious design work on the airframe. I'm thinking of a hardshell ABS plastic gun case or golf bag carrier. I'll be transporting my TX in a separate case.

Thom

So how big is a normal suitcase and is that the male version or the female? Max length width and depth............. Ray how about between the booms? Plug in outer wings,fuse,fins etc

The booms on my plane are CA'd to a cross piece that reinforces the wing, but if those booms fit into slots and were removable, you could remove the booms and fit the plane in a suitcase.

I have a plan for a 72" skymaster the booms pug in on that all wood.... Carbon fishing rod section booms are light and rigid asw they are spiral wrapped.

Airboatflyingshp: That plan sounds like just the thing I need. Can you provide for source for it?
Thom

take a look at the simplified 62" version in the first link I provided icrease it and check out the other links till you find the Turbo pusher skymaster increase the size of the first but build the wing in three pieces, use plug in booms carbon rod or balsa ply box, with a captive nut or threaded plate and use screws/screw headed bolts or cut down small plastic wing bolts just to stop it unplugging at the wrong moment!

I can dig the plan out but its an old Royal pkit plan and its solid, very solid model. XPR1 might work as a starting point.

another link someone is on a similar track here ..Ive cross linked threads http://www.rcgroups.com/forums/showt...7#post11944764

scale subject for the same job http://www.flyelectric.ukgateway.net/optica.htm

One I built from a Foam glider.