Introduction: 3D Printed Modular Mars Habitat Model
All my life I've dreamed of humans traveling to another planet. It's starting to look like I'll see that happen in my lifetime! Inspired by the Space X Mars One habitat, this 3D printed model is a fun way to explore the possibilities (and constraints) of living on other planets.
The most interesting thing about the Space X version of the Mars habitat to me is that it's designed to be modular and expandable. It consists of a single capsule with rocket boosters for landing, and four hatches that are equidistant around the perimeter. With this configuration, tunnels can be attached to the capsule at any of the four doors, connecting modules together. These might include crew modules, science labs, supply storage, and greenhouses to support an extended stay on the Red Planet.
Making your own 3D printed Modular Mars Habitat Module is a great way to experiment with articulated and fixed joints, and printing multiple modules will allow you to create your own scale model of a mars expedition.
Step 1: Design in 3D
For me, the Space X Mars One habitat is the most interesting design for living on mars for a number of reasons. Most importantly, it's designed to be a permanent settlement, which means it's built to last and to be expandable. The module has four equidistant doors, so it's easy to imagine how you could easily land new modules or inflatable structures and attach them.
This also seemed like it would be the most fun as a 3D scale model. I could print more of the modules or design new components and snap them together to make an entire colony!
I designed the model in Fusion 360 because it's easy to create precise models and keep track of changes. It's also a dream when it comes to 3D printing- just right click on the model, save as STL, and send it to your print utility. Unlike a lot of other programs I've used, I've never had any issues with the geometry translating to a solid printable model.
Fusion 360 is free for students and hobbyists, and there's a ton of educational support on it. If you want to learn to 3D model the kind of work I do, I think this is the best choice on the market. Click the links below to sign up:
I printed this project on the Dremel 3D Idea Builder. This machine is a workhorse! I found it to be reliable and consistent with quality prints, and it's much quieter than a lot of the other FDM machines I've used. You can buy one at Amazon, Home Depot, Lowes, or Best Buy.
I wanted the model to be as realistic as possible, so I designed it to be made of a bunch of separate parts that fit together. The parts are...
- Legs (4)
- Heat Shield
- Hatches (4)
- Portholes (4)
I also designed a tunnel that connects 2 modules. I didn't print it for this version, but it's in the .f3d file if you should want to print one and connect multiple habitats.
I basically eyeballed the design from looking at the Mars One renderings I could find online. If you have a picture with a scale figure (astronaut), it's easy to estimate the size of the module and the dimensions.
All the parts are friction-fit, meaning everything snaps together without the need for glue. The tolerances that seemed to work best were .05mm for parts that are supposed to be fixed, and .1mm for parts that need to move freely (like the hinges).
Step 2: Export Parts for Printing
To get the model parts to the Dremel Dream Builder, I exported STL files. In Fusion, you can send the file directly to Meshmixer (or a couple of other 3D print utilities), but I guess I'm old school- I like to save the STL files in a folder so I can keep track of what I'm doing. Sometimes prints don't work the way you'd hoped, and it's helpful to have a clear list of parts with date stamps so that you can revise the parts you need to.
In Fusion, you can right-click on any component or body and save as an STL. It's important to pay attention to the way your components or bodies are constructed. It's possible to have a single component with multiple bodies that need to be printed separately, so you have to keep track of which parts can be exported as components or as single bodies.
The settings I used for every part on this model were the default "High" refinement settings. This seemed to work well with all the parts and assemblies.
FILES IN THIS STEP:
- .stl Files: These are the individual parts of the model exported for 3D printing. These don't have support structures or orientation optimized for printing.
- .g3drem Files: These are the print files for the Dremel Idea Builder. The files have support structures and optimized orientation, and printed with good results for me on the machine.
- .f3d File: This is the Fusion 360 file for the entire model. Feel free to play around with it and tweak it for your own diabolical purposes.
Step 3: Prep Using Meshmixer
I used Meshmixer to prep my files for printing because it gives you a lot of control over the model while providing useful default settings that you can tweak slightly to get the results you want. Meshmixer has settings loaded for the Dremel Idea Builder (build volume, etc.) that help you position your model and create support structures. Here are the steps for prepping a model for printing.
- Position the model: This may seem like a no-brainer, but you have to think about how the printer works. FDM printers lay down strands of molten filament that basically solder to each other. This means that the orientation of your parts matters, especially for small parts.
- A thin linear element will snap in half with no effort if it's printed vertically on a bed. That's because the layers of filament are creating slices along the short axis.
- What I've found from printing on the Dremel is that parts less than 3MM thick need to be oriented so that the layers of material are parallel to the build platform. This makes for a strong, resilient, flexible, durable part. The diagram in this step illustrates what I mean here.
- The "bottom" of the model should touch the bed in most cases. In the case of the shell in the screenshots, the rim at the bottom is touching the bed.
- Create Support Structures: When creating support structures, I found I had the best results when I used the default settings within Meshmixer for the Dremel Idea Builder, but I increased the density of the support structures from 50 to 75. With a lot of the prints a density of 50 was fine, but I found that with significant overhangs (like the openings of the hatches in the shell model in the screenshots) 75 yielded better results without being too much of a pain to clean up. The support structures generated by default in Meshmixer have narrow tips and narrow bases, so it's very easy to snap them off of the finished models. Under Advanced Support, be sure to check "Allow Top Connections". It's important to have this feature checked for this model because there are a lot of overhangs and open holes.
- Send to the Dremel 3D App: Clicking the "Send to Dremel 3D" button brings you to the next step.
Step 4: Print Using the Dremel 3D App
After clicking Send to Dremel 3D in Meshmixer, it's time to build the model. All you have to do in Dremel 3D is click Build.
- LAYERS: I used Resolution: High for all of the prints. I had good results without tweaking any of the other options on this tab.
- INFILL: I used Fill Pattern: Hexagon for all the models. I changed the density from the default 35% in a few of the models. I found that especially on smaller parts, 75% density made for much sturdier parts.
- SPEED: Default settings.
- TEMP: I increased this to 230ºC from the default 220ºC. I did this because I've had better results with higher temperature in other FDM printers, and I found the same was true with the Dremel Idea Builder.
- OTHERS: Default settings.
The software gives you an estimate of the build time and the material used when it's done creating the file (which is awesome). You can send the file to the SD card or directly to the printer with a USB cable.
Step 5: Prep the Build Platform
If you're doing lots of prints, I find it's very helpful to have a disposable surface you can replace quickly. I use 3M ScotchBlue 2090 Painter's Tape as a build surface because it's large enough to cover the whole bed- this way you don't get any seams.
- Apply the Tape: The first step is to line up the tape on the bed so that it doesn't cover up the slots for the built platform clips. It's really important to smooth out the tape so there are no bubbles. I've found that my driver's license is the best tool for this job.
- Sand with 220 Grit Sandpaper: This removes the slippery finish on the tape, allowing the filament to stick to the bed easily.
- Wipe Down with Isopropyl Alcohol: This removes the sanding dust and any oil from your fingers that might still be on the tape.
Give it a few seconds to dry and you're ready to go.
Step 6: Level the Build Platform
The build platform must be level for prints to build properly. I've found that with near constant use, I only had to level the platform once in three weeks. If the filament doesn't seem to be sticking to the bed at the very beginning of a print, there's a good chance the build platform isn't level.
The instructions on the touch screen are pretty straightforward. Basically you just put a piece of paper between the nozzle and the bed and adjust the screws until the gap is just right. The paper should easily slide in and out in the gap while having a very small amount of friction.
There are only three adjustment screws, so it's easy to level the platform quickly.
Step 7: Unload / Load Filament
To unload the filament, just follow the menu. It'll heat up the extruder if it isn't already preheated, then ask you to press the extruder intake spring and pull the filament out. To avoid filament jamming, push the filament in for about half a second, then pull it out. I've found that this clears the extruder of any leftover filament blobs, which can create jams if you let the extruder cool down again before loading more filament.
To load filament, just follow the menu again. The motor will run automatically for a few seconds to load the filament into the extruder. Check the nozzle and make sure a little filament has come out before printing. You may need to go through the load process again to make sure it's totally full. If the extruder isn't full when a print starts, it's possible that filament won't come out at the very beginning of a print, which can cause problems with your print down the line.
Step 8: Preheat and Print
Preheating is a good way to ensure that the extruder is warmed up and ready to go. I had the best results by preheating the machine for about 5 minutes, then loading the file.
Loading a file to print is really easy with this machine because the touch screen gives you a preview of the model! Just pop in the SD card, select the model from the list, and tap Build.
NOTE: Files may FAIL if they're not in the MAIN DIRECTORY of the SD card. I found that using sub-folders on an SD card made about half of the files fail, so be sure to keep everything on the main directory.
Step 9: Remove and Clean Up
Most models can be popped off of the bed by hand, but the Idea Builder comes with a multi-functional plastic spatula that will do the trick if your fingers won't.
Believe it or not, I found the best tool for scraping the support structures off of the models was the can opener on my Leatherman Multitool. It's not sharp enough to hurt you if you slip and poke yourself, and the pointy end is great for digging into the little crevasses.
Step 10: Assembly
All of the parts on this model snap together without the need for glue. Here's the sequence of steps:
- Attach the feet to the heat shield. The 4 feet slide through the pill shaped holes on the concave side of the heat shield, then snap in place.
- Insert the 4 rockets into the holes on the shell.
- Insert the floor piece into the shell. There are raised knobs on the under side of the landings at each door- these line up with the holes in the floor and keep the floor in place.
- Snap the heat shield onto the bottom of the shell. The feet should line up with the rockets when these snap together.
- Insert the portholes into the holes on each of the doors. Notice that the portholes have a concave back to fit the doors properly, so you have to orient them. A NOTE ON PRINT ORIENTATION: If I had printed these doors so that they were oriented vertically on the bed, the posts would have easily broken off. Since the printer applies layers of filament on top of one another in the Z axis, it's important that delicate pieces like this are oriented horizontally.
- slide the door hinge posts into the hinge holes on the shell. The doors should swing open and shut freely. The tolerances here were a little too tight in my design, so I had to file down the inside of the doors at the hinge edge to make them close.
- Snap the lid in place. This part has notches in it to keep it oriented the right way (I should have done the same thing on the heat shield!).
Step 11: Colonize Mars
I'd love to see multiple copies of this model fitting together to make a Mars colony. The "Tunnel" component in the Fusion model can be printed to connect multiple habitats, and I was thinking about using white balloons and printing tension rings to make a kind of inflatable greenhouse. I hope to see some copies of this project show up on the interwebs. Post an IMadeIt and I'll send you a free 3 month pro membership!