3D Printers: The Ultimate Tools For Model Rocketry
By: Mario Perdue
About the Author
I have had a life-long interest in space and rocketry. I started building and flying model rockets in the mid-1960s and have continued doing so ever since. This hobby lead to a tour of duty in the United States Air Force, Strategic Air Command, as an ICBM Missile Systems Electronic Equipment Specialist. After leaving the USAF, I continued working in the computer electronics field before migrating into software design.
A Bit About Model Rocketry
The hobby of Model Rocketry began in the 1950s. Inspired by the success of the Soviet Union’s Sputnik satellite, young people around the world began building and flying their own designs, often with disastrous results. Model Rocketry was developed to provide a safe source of rocket motors.
Model rocketry hobbyists have been quick to adopt new technologies. Rocketeers could be found flying a variety of technological payloads - cameras, altimeters, tracking, and telemetry radios all became common. In fact, one of the earliest personal computers, the MITS ALTAIR, was developed to process telemetry data from model rockets. Rocketeers were also early adopters of LASER cutters for making complex fin shapes from sheet balsa. As technology has continued to evolve, model rocketry hobbyists have incorporated the 3D printer into their workshops. 3D printers are incredibly useful tools for hobbyists.
3D Printers: Perhaps the Perfect Tool for Model Rocketry
While there are modelers who can build very detailed models using standard building techniques, 3D printers can make it easier, and adopting the 3D printer for building model rockets makes perfect sense. Almost everyone involved in the hobby has access to a computer that can run some sort of CAD or 3D Modeling program. You don’t have to spend big bucks on the software, either. There are several free and/or inexpensive CAD and modeling programs available.
On my iMac Pro, I use Cheetah 3D. It’s designed for animation and gaming, but it’s a very easy-to-learn program that is well suited to designing parts for 3D printing. This new design and build paradigm allows modelers to more accurately create parts for their models, including recreating the parts damaged in flight.
Likewise, there are many printers available on the market with a wide range of prices. You can probably find one that will fit your wallet (or pocketbook). In my case, I chose to design and build my own printer to address my specific needs. If you choose to go this route, don’t scrimp on your controller board. I’ve tried out a variety of them so I can say from experience that the control board can make or break an otherwise good 3D printer. My printer uses the Duet 2 WiFi and Duex 5 Expansion Board. This printer has a lot of motors – four are used on the Z-axis for automatic bed leveling and I plan is to add a tool changer so all of those additional ports will be used. I highly recommend the boards from Duet.
Another important part of the printer is the extruder and hotend. It doesn’t matter how well your gantry can position the hotend if it and the extruder can’t deliver a proper flow of plastic. Again, I have tried a lot of hotend and extruder combinations and I have found that the E3D Hemera works the best for me. My printer is a direct drive system so it’s important to keep the size and weight down as much as possible. The Hemera does this nicely. The built-in dual drive extruder does an excellent job of feeding filament to the HotEnd ensuring a smooth flow for the entire print.
The Vostok
My hope for this blog is to share how 3D printers can improve the quality of model rockets, and my inspiration came from a desire to modify and improve a previously built model of the Vostok with 3D printer parts. The Vostok carried the first man into space — you can’t get much more iconic than that.
I only added a few details to the R-7 booster (everything below the open framework near the top), but the Vostok spacecraft on the top was swapped with a newly designed, 3D-printed replacement.
For the Vostok, I chose to print it in eight parts. Doing this allowed me to use a larger nozzle where detail wasn’t a big issue and switch to a smaller one for moderate detail and still a smaller one for the parts with the open lattice structure. I won’t go into the actual design process here because it’s really beyond what can be quickly covered but it was all done with solid objects modified using the boolean operations, add, subtract, and intersect. The solid objects were then output to .STL files for printing. Note that all the parts are hollow. This reduces the weight of the parts, something that’s important for a flying model, but still provides a good structure. I normally design for a 2mm outer shell but sometimes, when weight is a critical factor, I will drop that down to 1mm.
Other Projects
Printing parts for model rockets is a great use of 3D printers but there are other uses related to model rocketry as well. I often need to print custom assembly jigs or alignment guides. For rockets that won’t stand on their own, I print display stands. These are normally simple devices with three legs that are inserted into the engine holder to allow the rocket to stand on its own but they can be far more involved. I’m currently building a full mobile launchpad with the launch umbilical tower to display a Saturn V model. This display stand will be lighted and stand over 6’ tall when complete. It may be the most over-done display stand ever made.
Another area where 3D printing works well is building various launch equipment. I have built launchpad pivots for smaller model rockets that work well and are cheap and easy to replace if they are damaged. I also use my printers to create the panels for a wireless launch control system that I build. With the exception of my handy X-acto modeling knife, it’s safe to say that my 3D printer is my most used model rocketry tool.
If you’re interested in learning more about the process of 3D Printing Model Rockets, read Mario’s Guide.
*First photo is from: https://cults3d.com/en/3d-model/various/vostok-k-rocket-model
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