Export rockets into 3D printable formats?

[Jimustanguitar]

Hi guys, newbie here. Jim from Notre Dame / South Bend.

I'm part of a local MakerSpace called The MakerHive ( https://www.facebook.com/themakerhive ) that co-hosts the Midwest RepRap Festival here in town ( https://midwestreprapfest.org/ ) Several of the guys at the Hive are into small rockets, and we'd like to have a 3D printed model rocket competition at the festival in March. We had over a thousand people attend last year, and there were over one hundred 3D printers running at the show, so we think it'll be a hit if we can organize it in time.

Anyway though, as I started digging into designing my own rocket, I discovered cool design programs like OpenRocket and RockSim, and it made me wonder if any of those tools can export 3D models of rockets and their parts for actual manufacturing. A few searches didn't yield any results, so I figured I'd ask the experts!

Do any rocket design programs export .obj, sketchup, or .stl files?
If not, which program's contributors should I suggest this to?

Thanks guys, looking forward to joining more conversations on the forums!
Jim

 

[whaleshark77]

I'm pretty sure that Rocket Sim can be used create 3d models of a rocket in those formats. You might have to experiment a bit.

Good Luck!

 

[gpoehlein]

Welcome to the forum, Jim, from a fellow Hoosier (at the southwest corner of the state). I've been tinkering with 3D printing myself (I have a Deezmaker Bukito) and have created several rocket parts which I have posted on Thingiverse. Unfortunately, neither OpenRocket nor Rocsim export files in any format suitable for 3d printing. I design all my parts using OpenScad. Using that program, I have created parametric nose cones in both elliptical and conical shapes - they work quite well. I also created the reducer section for the Estes Black Brant II as well as the tail cone. Because I can only print in PLA right now, (the Bukito does not have a heated bed, so ABS doesn't print well on it), I haven't tried printing fin cans or other parts that would be susceptible to warping from either higher environmental heat or motor heat/exhaust.

 

[Jimustanguitar]

Welcome to the forum, Jim, from a fellow Hoosier (at the southwest corner of the state). I've been tinkering with 3D printing myself (I have a Deezmaker Bukito) and have created several rocket parts which I have posted on Thingiverse. Unfortunately, neither OpenRocket nor Rocsim export files in any format suitable for 3d printing. I design all my parts using OpenScad. Using that program, I have created parametric nose cones in both elliptical and conical shapes - they work quite well. I also created the reducer section for the Estes Black Brant II as well as the tail cone. Because I can only print in PLA right now, (the Bukito does not have a heated bed, so ABS doesn't print well on it), I haven't tried printing fin cans or other parts that would be susceptible to warping from either higher environmental heat or motor heat/exhaust.

ProfWunder, I presume?

I don't know if you can make the trek up to Elkhart for the festival in March, but if you've got a rocket design that you want me to try printing and launching for you, I think it would be a lot of fun! I've got a Rostock Max, so I can print ABS with a build area of about 12" diameter by 18" high. Most of the locals here have Rostock's because SeeMeCNC (the manufacturer) is up here in northern Indiana as well. With that kind of build height, it's conceivable that you could print the entire rocket, body tube and all, as a single piece just like a "normal" vase would print. That's what I'm hoping to try. Gotta figure out a recovery scheme though. Perhaps the motor mount ejects with the charge instead of the nose cone. I've also got a hair-brained idea to make the whole rocket have dimpled a golf ball texture... Can't do that with a cardboard tube.

 

[teyrana]

@Jimustanguitar, @whaleshark77

Openrocket doesn't currently have the ability to export / import from STL. It certainly sounds like a useful feature.

( https://midwestreprapfest.org/ ) Several of the guys at the Hive are into small rockets, and we'd like to have a 3D printed model rocket competition at the festival in March.

That festival sounds really cool, I've always been interested in 3D printing, but never found a compelling use case. What are the rules like? Do you guys want to fly 100% 3D printable structures? (excepting obviously, engines & recovery devices ) Or is it some random % by weight? Do you generally print ABS or PLA? (I'm assuming no one has access to an SLS / DMLS machine, right?

Anyway, it sounds like having Openrocket export STL files would be the 80% solution, right? Was that what you were thinking?

If not, which program's contributors should I suggest this to?

You just have (There are quite a few OpenRocket developers on here, myself included )

Anyway, it sounds like an interesting idea. I'd love to hear what you think!

 

[Jimustanguitar]

The MRRF festival is awesome. It's like an all weekend makerspace. The first time I went I expected vendor booths and product demonstrations and things like that, but instead of being a big marketing thing, it was all of the people from those groups hanging out and helping each other on their projects. Last year there was everything from laser metrology to new machines that were moving for the first time to 3D printing mold investments for custom logo waffle irons. It's a very eclectic bunch. It's a heck of a lot of fun for free.

We haven't nailed down the rules much more than standardizing on a C sized engine that we can buy in bulk. There's been talk of standardizing a telemetry payload too (probably an arduino pro mini with accel chips that we make ourselves). Whether or not the rockets have to be 100% plastic has yet to be determined. Many people don't have a machine big enough to do 'fun sized' fuselages, so my guess is that body tubes will be allowed. Maybe engine mounts too, but those could easily be printed unless it poses a safety concern or melt risk.

There's also talk of an unlimited class, and more than one guy has gone out to buy some powdered sugar. Seen this yet?
[video=youtube;12fR9neVnS8]https://www.youtube.com/watch?v=12fR9neVnS8[/video]

I don't think that having an STL export in a rocket design program is a showstopper for an event like this because everyone is already drawing and modeling in some program or another, but an actual rocket design software would be a much more scientific approach to doing it, and a valuable tool for the rocketry hobby in general. 3D printing is definitely an applicable technology to the hobby, an inevitability probably. Nobody is mass producing things in huge quantity runs like a factory, it's a very customized and personal thing that would be great for rapid prototyping one of a kind parts to share with a community.

I don't know the nuts and bolts of STL files, but they're definitely the standard in home 3D printing. Eventually everybody will switch to AMF files, but that's been slow moving. https://www.shapeways.com/blog/archives/898-AMF-A-Better-File-Format-for-3D-Printing.html Hopefully STL files are similar to the 3D graphics renderings that the design programs already do. Maybe there's even an intermediate program that could convert them that works today...

 

[gpoehlein]

ProfWunder, I presume?

I don't know if you can make the trek up to Elkhart for the festival in March, but if you've got a rocket design that you want me to try printing and launching for you, I think it would be a lot of fun! I've got a Rostock Max, so I can print ABS with a build area of about 12" diameter by 18" high. Most of the locals here have Rostock's because SeeMeCNC (the manufacturer) is up here in northern Indiana as well. With that kind of build height, it's conceivable that you could print the entire rocket, body tube and all, as a single piece just like a "normal" vase would print. That's what I'm hoping to try. Gotta figure out a recovery scheme though. Perhaps the motor mount ejects with the charge instead of the nose cone. I've also got a hair-brained idea to make the whole rocket have dimpled a golf ball texture... Can't do that with a cardboard tube.

Yep - that would be me. I haven't got anything right now, but I'm always playing with different ideas so who knows. And if you are ever inclined to come down to one of our Launch Crue launches, you would be most welcome. Check our website (link in my signature) for our calender of launches and contests as well as a map to the farm where we fly. All are welcome whether NAR members or not! And, except for the winter months, we usually have a high power waver in effect, and can fly up to about J motors at our field.