Hi Guys,Some time ago I started a post with some ideas about making a UAV using rapid prototyping to construct the wings and fuselage......I suppose my initial idea came from a thought that it would be great to create an airframe that has been designed from the outset as a UAV and with my experience of RP I know how simple it is to make complicated thin wall shapes with these machines. Currently you either have to make a UAV like from an RC kit or go down the route of using expensive composites with all the attendant tooling and production costs. I wondered if it was possible to design something that could be printed off from an RP machine have a minimum ammount of prep work done to it and then asembled and flown......Is the future of commercial UAVs acceptance going to be limited by the current construction methods? if you can print off a UAV like you do a sales brochure the problems of crashing and damaging airframes becomes less of an issue, got a hazardous mission? send in the UAV, if it never comes back we can just print another......Henry Ford said " If I asked my customers what they wanted they would of asked for a faster horse!"I have attached a pic of one of my concepts that shows an idea of what I am attempting to do. The idea is to print off the wing and then stiffen it up with a bonded on carbon fibre spar. The CAD concept shown is 33" long, 7.75" wide it is made from 1mm thick polycarbonate and weighs 500grams can anyone tell me how far off being an acceptable weight this is? The carbon fibre spar would fit into a carbon fibre box section bonded into the fuselage. The fuselage would be made using the same process as the wing.My next job is to try and optimise the concept using cosmos to see if it can sustain +/- 6G with carbon spar fitted in the wing and to see if I can loose some weight anywhere. Let me know what you think!RegardsOliver
Taking the half-half fabrication idea mentioned, how about this method: cut balsa or light-ply ribs using a CNC laser, then print the top and bottom sections of the wing separately. Include grooves in the printed wing halves where the ribs will be, so that it is easy and quick to glue in the ribs. Glue the ribs in the grooves, then glue the two halves together. This process would also allow for easy installation of electrical wires, or gas lines in the wings of more advanced models.
I don't know tons about CAD - would it be possible to make an automated process that would take an existing wing design and create the required CNC code for each piece? That would make for a quick build!
What if you printed just the ribs, essentially everything in your picture above except the skin, then had an easy covering method like a shrink wrap bag of some sort...it may not be as quick, but it could be lighter. Additionally, if you were going to go that route you could make all of the ribs thinner and maybe even go to something like a thin walled honeycomb internally - significant strength, less material. Just some thoughts.
Have you attenpted to print a single section rib to rib? It seems to me that the wing covering (skin) would be difficult to print since it is not supported in the middle.
The reason I asked about making the ribs out of another material is because they don't need the higher strength that the polycarbonate provides. One way to reduce weight would then be to make the top and bottom half of the plane shell as two separate pieces and place balsa ribs in between the halves before gluing it all together.
It sounds like that defeats your purpose though. If you would rather be able to print the plane as one complete piece, you're going to have to add some weight. With the right wing design, this shouldn't be a problem. I have a plane that I've designed and am currently building which could accommodate this additional weight without much trouble.
First, I really like your idea for using RP to manufacture planes. My primary concern with the idea is the surface finish that your wing will have. How much sanding (if any) is involved in finishing these parts?
Are the ribs you have in your CAD model going to be made from polycarbonate also? I would think one way to reduce weight would be to create the ribs out of something lighter, like balsa, rather than the polycarbonate. What's the density of the material you're planning to use? That will help determine whether it's worth making it all out of polycarbonate or making the ribs out of something else.
As for your 500 gram weight, that sound a bit high. There is no easy answer though, it all depends on how much payload you need the plane to carry. You might be able to get away with this weight, but you wont be able to carry as much in electronics. The airfoil you choose will also impact whether or not this weight is acceptable. What have you chosen?
Anyway, it's an interesting project. Please keep updating on how it's going.
Nice drawing! What software did you use?
Manufacturing of CNC components you speak of could be achieved within DIY drones community: Differences in foreign exchange rates could make it cheaper for some members.
I use CAD (Microstation) every day, as an Architect, and don't have first-hand knowledge with CNC technology (although we've recently used it to model parts of a project I'm working on).
I'm aware .dwg format is the international standard for Architecture & Engineering, but can anyone tell me if there is an "international" file format for CNC tech?
Looks good. Just a FYI--it's more effective if you embed images in your post, rather than attaching them, to save people from having to click. Use the little camera icon.
Replies
I don't know tons about CAD - would it be possible to make an automated process that would take an existing wing design and create the required CNC code for each piece? That would make for a quick build!
It sounds like that defeats your purpose though. If you would rather be able to print the plane as one complete piece, you're going to have to add some weight. With the right wing design, this shouldn't be a problem. I have a plane that I've designed and am currently building which could accommodate this additional weight without much trouble.
RP is really only cost effective when the parts being produced are expected to change significantly on a daily basis.
I believe Boeing already made and flew a fully RP drone, not sure if a market emerged.
First, I really like your idea for using RP to manufacture planes. My primary concern with the idea is the surface finish that your wing will have. How much sanding (if any) is involved in finishing these parts?
Are the ribs you have in your CAD model going to be made from polycarbonate also? I would think one way to reduce weight would be to create the ribs out of something lighter, like balsa, rather than the polycarbonate. What's the density of the material you're planning to use? That will help determine whether it's worth making it all out of polycarbonate or making the ribs out of something else.
As for your 500 gram weight, that sound a bit high. There is no easy answer though, it all depends on how much payload you need the plane to carry. You might be able to get away with this weight, but you wont be able to carry as much in electronics. The airfoil you choose will also impact whether or not this weight is acceptable. What have you chosen?
Anyway, it's an interesting project. Please keep updating on how it's going.
Manufacturing of CNC components you speak of could be achieved within DIY drones community: Differences in foreign exchange rates could make it cheaper for some members.
I use CAD (Microstation) every day, as an Architect, and don't have first-hand knowledge with CNC technology (although we've recently used it to model parts of a project I'm working on).
I'm aware .dwg format is the international standard for Architecture & Engineering, but can anyone tell me if there is an "international" file format for CNC tech?