Mona Lisa ParaFoil

The card wings weight 32 g on their own and thats just the uppers. So I'm going to use a4 paper instead and ply it up for the cross members etc. Gotta find some black a4 paper now doh!

Tuns our its about 15 grams that the little crazy flie can lift! I rigged up a little tube and popped it on the top cranked up the engine and swapped over screwdrivers....so 15g to play with......getting it to fly will be tricky then certainly vertically anyway....or can I get the card to fit withing 15 g???

I've decided that my engine probably still wont cut it. I've cut weight as much as I can but I had no basis for why? So I've rigged up a little test using the mounting holes on the bottom of the crazy flie. I've attached thread to this on the bottom (out of the way of the spinning things) and then to a linkage and tonight I will attempt to see which size watchmakers screwdriver it can lift......I may not have a working crazyFlie in the morning!

So It's advance a fair bit but I'm not sure I'm going to get it done in time as life rather got in the way as it were. But no worries I have made some good progress which I will pop in the pics as soon as I can get them to upload.....

Ver 0.01a is still in alpha for sure and it has a long way to go so I'm unlikely to make the deadline and get it flyable but I will try still. The project has morphed into creating the templating for the next version and a card proof of concept. Which will now try to explain.

I have created black cardboard folded wings which ideally be morphing by the use of a mechanism. This will allow me to test the best aerofoil sections for performance. Currently there inst much of an angle on the wings which wasn't my original intention. However this is now going to be a test bed for rapid prototyping of my finalised design. So new cardboard wings will be added and amended as needed.

Central to this is the power source. What I will call the aerocore (tm pending lol). This is to be a solid box structure containing a crazyFlie which will pivot around the central axis. The wings will attatch to this box and there will be minmal other structure around the box other than a leading edge and a trainling elevator/alerons. See below. This will give a vtol effect and should (if my non existent maths are correct) give me a convertible hybrid VTOL. If all doesn't go to plan and my engines aren't powerful enough then The central aerocore can be swapped out for a different power source. My inspiration was the upcoming XTI tricoper/VTOL and the project Zero aircraft. The central aerocore will pivot round in it's entirety but also have a hover craft like control for vectoring the resultant thrust and giving it a measure of control in the horizontal plane. This may be supplemented by rudders on the vertical stabilisers with mini servos for control or other control methods such as bleed air or puffer motors on the trailing edges of the wings. This is in the tail sitter configuration. Hat tip to one of my friends who is an aero engineer for that one. This should supplement the quad copters control in a vertical tail sitter configuration.

In a traditional VTOL configuration with the QUAD locked in the horizontal plane. Puffer motors might give useful control also however this will be discovered as and when it flies. Another route would be to use bleed air from the central aero cores power however I'm not at all sure if that would work reliably on this scale. Again this would be one of the attempted configurations. This may require a thicker wing in order to accommodate the ducting (straws!).

Other wing materials will be studied however card at the moment offers me the easiest and quickest route to form both the wing structure and the central aerocore box structure. The key to this will be the initial design which has flexibility, crashability and rapid re-configurability inherent in it. Simple cheap design with good expansion for the future as my skills and knowledge expand.

This has been a great experience in learning and research for me as I am trying to apply rapid software design methodology and spirit to designing hardware of which I have little experience. Thanks.

http://www.rcuniverse.com/forum/rc-gliders-sailplanes-slope-soaring-112/11392456-nodds-plank.html

Last plane I made was a wooden sail plane years ago. Didnt fly too well in fairness. This is interesting reading. Mine is going to be more V wing though I think.....Maximise the frame to surface area ratio weight wise too. Used to have an old RC flying wing..... really should'nt have binned the broken foam!!!

Having done some more head scratching. I feel a Para-foil as such is too unstable in any sort of wind. Action mans parachute never did quite work!!! I've assembled my kit for a first prototype. I've got an old fold-able mini helicopter IR controlled (with two "channels") which had a tail rotor for horizontal control. And I've found a cheap UFO style contrarotating IR controlled model which is Thrust only. So I'm thinking bodge together a very light weight wing frame and hey presto most of a rudimentary VTOL. Both of these RC flyers as helicopters are counter balanced however my concern is the pulling power of the foldable blades on the motors. I've trimmed most excess wight off but having weighed that as accurately as I can on kitchen scales. 5 grams probably is going to be tricky to make a rigid box structure to hold the motors and a frame for a cling film aerofoil wing.....I have an old broken shaver with a good small motor which combined with a prop could provide some more pulling power instead of one of the motors with some careful surgery to remove the old motor and replace it perhaps.

So it has potential and expand ability if all else fails. Possibly Pop my crazy flie in the centre box as another power source and get it to transition to vertical flight using a top or bottom mounted elevator/flap. I'd rarther use what I have though as it'll be more of a challenge and probably more comical too!....

• Cling film or the see through PVC film I bought as the wing covering that is my question?
• Balsa dowl for the central frame and possibly wing spur?
• Plastic straws for leading and trailing edges and/or internal frame of the wing I think is a possibility also to keep weight down but obviously at the expense of crash-ability! !!!

Scaled it back and salvaged what I had already around the house put together my roungh BOM on the floor. With a couple of additions. Wooden dowl probably for the main spar. And a cheap IR controlled UFO from a local department store to provide power for the 0.01 version. Weight is key so I've cut back all structure from the power and control units and will tape and stick it together as lightweight/cheap and throwaway as possible for the first version.

Use thin carbon fibre sheet as canopy/envelope - make it more like a microlight with good thrust to weight ration, forward mounted mid or top of wing motors/props to take advantage of coanda effect and try to protect the prop blades. Improvements here would be lower weight and more manoeuvrable wing/canopy.

Examples: https://carbonflyer.myshopify.com/

Reading: https://en.wikipedia.org/wiki/Coandă_effect

Added my initial rough design pics......does'nt like chrome apparently!!! Grr will try again later.

Possibly Paper Concertina para foil with stiffer sections for elevators. Weight and control using this method may still be an issue and this could increase size. Idea: Use v thin plastic coated card folded. Like a paper aeroplane. Or standard smaller Nylon envelope which folds out along slightly stiff thin plastic folded rods. Again weight and balance could cause issues with this.