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Topic: FreeCAD or Blender for an RC C-130 Hercules

I am currently scratch building a remote controlled C-130.  Boy is it slow and gluing balsa together is too 80's.  I want to try to print one, however I'm 100% new to 3D printing - why start small . . .

I cleared a major hurdle when I found a file of a 3D C-130 on turbosquid that I'm pretty sure I can import into FreeCAD and Blender as an .obj file.

I found a plane for free on turbosquid that I have been experimenting with in FreeCAD.  I may have run into a problem because FreeCAD says it is not really intended for mesh drawings.  The topic I read said Blender is a better program for mesh drawings.

My plan is to use the exterior of the drawing to scale the plane to the completed size I want.  Next divide the plane into sections that will fit inside whatever printer I end up with.  Next create the desired thickness of the exterior.  Next create an interior skeleton for strength.  Then print and glue sections together.

Which of these programs should I use, or is there a better one that's free.  I have only 4 hours experience with FreeCAD and none with Blender.

Also will this even work or is my plan impossible?

Thanks

2 (edited by pirvan 2013-10-06 05:55:09)

Re: FreeCAD or Blender for an RC C-130 Hercules

schafe wrote:

I am currently scratch building a remote controlled C-130.  Boy is it slow and gluing balsa together is too 80's.  I want to try to print one, however I'm 100% new to 3D printing - why start small . . .

I cleared a major hurdle when I found a file of a 3D C-130 on turbosquid that I'm pretty sure I can import into FreeCAD and Blender as an .obj file.

I found a plane for free on turbosquid that I have been experimenting with in FreeCAD.  I may have run into a problem because FreeCAD says it is not really intended for mesh drawings.  The topic I read said Blender is a better program for mesh drawings.

My plan is to use the exterior of the drawing to scale the plane to the completed size I want.  Next divide the plane into sections that will fit inside whatever printer I end up with.  Next create the desired thickness of the exterior.  Next create an interior skeleton for strength.  Then print and glue sections together.

Which of these programs should I use, or is there a better one that's free.  I have only 4 hours experience with FreeCAD and none with Blender.

Also will this even work or is my plan impossible?

Thanks

The reason the plane is made of balsa is because the wood's light weight.  Balsa is about 1/10 the density of ABS.  If you were to make all the same parts out of plastic, your plane might never get off the ground, or you'd need a motor 10 times the size to get it off the ground.

To print or, 3D print, that is the question...
SD3 printer w/too many mods,  Printrbot Simple Maker Ed.,  FormLabs Form 1+
AnyCubic Photon, Shining 3D EinScan-S & Atlas 3D scanners...
...and too much time on my hands.

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Re: FreeCAD or Blender for an RC C-130 Hercules

Yep, that is a concern too.  However I know that there have been at least 3 planes that have been printed.  1 has flown for sure - search youtube "first flight of a 3d printed plane." 

I think that balsa is not nearly as strong than ABS so you would use less material to have a finished plane.  In that video, the inside is much less complicated than the inside of balsa RC planes.

4 (edited by pirvan 2013-10-06 15:27:27)

Re: FreeCAD or Blender for an RC C-130 Hercules

schafe wrote:

Yep, that is a concern too.  However I know that there have been at least 3 planes that have been printed.  1 has flown for sure - search youtube "first flight of a 3d printed plane." 

I think that balsa is not nearly as strong than ABS so you would use less material to have a finished plane.  In that video, the inside is much less complicated than the inside of balsa RC planes.

I did look at the video, and a few things are immediately obvious.  First, the plane was printed on a high end laser sintering printer, not the kind we use.  I doubt you could achieve the precision and consistency of that printer on a large scale like they could.

Second, the frame was designed specifically for for that purpose, if you look at it, it uses very thin cross members in the wings, and a geodesic design for the fuselage support.  A non traditional design that allows them to have a very thin and light frame, compared to the spars and bulkheads of a traditional aircraft design.

Out of curiosity, are you planning on using printed ABS for the skin as well?

I for one am very interested in this, as I'm an RCer myself, although I'm into rotary wings.  So whatever you decide, I'd like to see the progress here.

As a side note, 20 some years ago, me and a group of my friends, decided to build a 1/8 scale Battlestar Galactica Viper, and we did, out of balsa and Styrofoam.  We installed the largest ducted fan we could buy at the time, but it couldn't get off the ground more than 3 feet, it merely hopped around, and all that was because of weight, and not enough lift.  We did mange to eventually launch it... As a rocket.  I don't remember what type of rocket engines those were, but it looked like we trapped 8 sticks of dynamite to the thing.  It went up about 200-300 feet and came down in about 20 pieces. smile

To print or, 3D print, that is the question...
SD3 printer w/too many mods,  Printrbot Simple Maker Ed.,  FormLabs Form 1+
AnyCubic Photon, Shining 3D EinScan-S & Atlas 3D scanners...
...and too much time on my hands.

5

Re: FreeCAD or Blender for an RC C-130 Hercules

I am still moving forward on this - slowly.  If nothing else, I'll have a neat C-130 to hang in the garage.  One nice part of printing your own plane is you can simply reprint badly damaged sections.

I want to print the entire plane just like in the video.  I'm not going to the extreme of printing control surfaces already attached however.

I will also have to pull out my inner Mythbuster to test ABS and PLA vs balsa and plywood of the same size for strength, weight, etc.  Eventually I will have to get printed samples of each material from a hobby grade printer.

I have not heard of anyone attempting this type of RC project.  Someone needs to try.  I'll give it my best.

Back to my original question.  Which program should I learn?

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Re: FreeCAD or Blender for an RC C-130 Hercules

schafe wrote:

I am still moving forward on this - slowly.  If nothing else, I'll have a neat C-130 to hang in the garage.  One nice part of printing your own plane is you can simply reprint badly damaged sections.

I want to print the entire plane just like in the video.  I'm not going to the extreme of printing control surfaces already attached however.

I will also have to pull out my inner Mythbuster to test ABS and PLA vs balsa and plywood of the same size for strength, weight, etc.  Eventually I will have to get printed samples of each material from a hobby grade printer.

I have not heard of anyone attempting this type of RC project.  Someone needs to try.  I'll give it my best.

Back to my original question.  Which program should I learn?

I like that, go for it, and keep us posted on the progress.

As far as which program you should use, I don't use either, so I can't offer any advice, but I did play with Blender before, and it looks like it's more oriented toward organic modelling.  FreeCAD seems to be more of an industrial, architectural and mechanical design type tool, so I'd start there.

To print or, 3D print, that is the question...
SD3 printer w/too many mods,  Printrbot Simple Maker Ed.,  FormLabs Form 1+
AnyCubic Photon, Shining 3D EinScan-S & Atlas 3D scanners...
...and too much time on my hands.

7

Re: FreeCAD or Blender for an RC C-130 Hercules

I would bet you could make a hollow wing that would be comparable to balsa wood in weight. If you wanted a little support then maybe a large honeycomb pattern for strength?  Like Pirvan said, keep us posted!

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

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Re: FreeCAD or Blender for an RC C-130 Hercules

After spending a night with FreeCAD and a night with Blender I'm going with Blender.  With no prior experience I have been able to scale and section the sample fuselage the way I think it needs to be.  Blender also has an instructional DVD to purchase detailing the 3D design for printing process. 

One idea I have is to print the wing sections with ribs that have holes lined up so I can epoxy a carbon fiber shaft through each section.  I might do this for the fuse also. 

Need to start looking into printers . . .

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Re: FreeCAD or Blender for an RC C-130 Hercules

The only thing I'm not sure about Blender, is it possible to properly dimension things the way you do with CAD software? From what I have seen, it's much more of a "creative" process where an artist will draw things out, but they're not software for highly accurate technical drawings and models the way FreeCAD or other things like Solidworks or Catia are.

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Re: FreeCAD or Blender for an RC C-130 Hercules

Anything can be made to fly!!


http://www.youtube.com/watch?v=i00thtWgvDs


They took a toaster and put wings on it.