Here's something I've been working for a few months, a fully 3D printed airframe, to test and practice the technology and to make a prototype of a design I've been wanting to build at a larger scale.
The airplane has a wingspan of almost one meter and the total weight of the airframe is around 400 grams, almost half of it from the wings, so later on I'll make foam wings with fiberglass skinning to save weight.
Here are some photos of the airframe and some parts:
I'm currently working on some small details, mostly on the interior figuring out the best layout for the R/C gear and making mountings and brackets for it.
If anyone has a 3D printer the complete files to print one at home can be found here: http://www.thingiverse.com/thing:272478
Comments
I have uploaded the Ready-To-Fly files to Thingiverse (http://www.thingiverse.com/thing:272478), that concludes Phase One of the project, having a complete design ready to print and fly.
Phase Two is to install FPV gear on it and conduct further flight testing and Phase Three is to install an autopilot to finally turn the plane into a small UAV.
I did the maiden flight today, it flies!
https://www.youtube.com/watch?v=Qf5Z83dHrow
I have to try dual rates on the controls, is a bit jumpy now... I'm also printing a new nose section because the second flight didn't end so well...
The plane is finished and ready to fly this weekend, I'll see if I can get someone to film it.
R.D. Sarwalt, oh... but where is the fun without the sphincter clenching adrenaline rush when you launch a plane for its maiden flight? :D
I was just doing some work on the plane, doing the pushrod installation and rotating 90 degrees the SMA plug on the OpenLRS receiver so it will fit better in the fuselage. With some luck I'll be ready to fly it next weekend.
Wait a minute... balsa is biodegradable, sustainable, and requires no electricity (if you use a razor knife), employs farmers, harvesters, wood mills, shipping companies, distributors, and finally the builder.
If we could only figure out how to make a balsa tree 'grow' our parts without the biz after farmers...
(I am joking...maybe.) (Hmmm.. a 3D balsa 'grower'. Perhaps a slurry of balsa dust/fibers with a binder for the droplets?? Quick -- off to the patent office!)
Well done and a fine effort! Bravo!
Perhaps you could find someone with skills in the R/C simulator community to model your dimensions, add the weight distributions, motor, prop, etc. That may provide an idea how it will fly before actually launching it with a running motor. I think too often we ignore that tool as a way of simulation for our ideas.
-=Doug
OuBen, a flying wing could be lighter yes, actually I've been thinking of making a small one using the same printing technique later on.
Eli, Harry, thanks for the links, I admit I haven't given aerodynamics enough attention on this design, mostly going by what looks right.
Alejandro, you could use a design calculator like this:
http://charlesriverrc.org/articles/design/SailplaneCalc2005-05-04.xls
One myth about V-tails is to take a conventional tail and convert it by using the projected area to size the V. It needs to have the total area of both horizontal and vertical. That makes them end up looking too big which is why my first comment. You can find lengthy discussions on it here:
http://charlesriverrc.org/articles/design/vtailmsganthology.htm
Alejandro - tail sizing is pretty straightforward. Here is a link to some details. It mostly comes down to a formula for your vertical tail area and one for your horizontal tail area. In the case of a v-tail, you can just use the projections onto those planes. the longer your fuse, the smaller area you need to have the same effect. There are some guidelines about values to look for. just eyeballing it, your tail looks a little undersized, but not dramatically so.
could fly wing save weight？
Harry, the size of the stabilator is something I'm not very sure about, it's a bit on the small side I think. What would you say is a good surface area in proportion to the wing area?
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