There is no shortage of reference material, specs, and kits for building a movie pack. I found that RGB packs are a different story. There are various examples of fan-made versions, Spirit repaints and mods, and the Viking Props version. There is definitely some cool work out there but there is no where near the amount of options and information as the movie packs. With this in mind, I felt this was a good project to dust off my solid modeling skills and start building up my own creative interpretation and put my low-end consumer grade Ender 3D printer to the test.
While this post will show some highlights, I've been tracking the full build story on my Instagram account (@GhostbustersGear)!
For context, my full-time job is running a professional digital design company - we do professional CAD, 3D modeling, and automation for architects and engineers. I use Rhinoceros 3D as my tool of choice for designing and creating accurate, water-tight models suitable for printing. For this project, I designed original 3D models from scratch for the Trap, Wand, and Pack. There was quite a bit of iteration early on to understand the Ender 3 tolerances, STL mesh resolution, and test the print settings.
For overall dimensions, I used my full-sized movie pack and props as a rough guide. However, the RGB packs are decidedly more "streamlined" in their aesthetics - they have a simple futuristic look to them rather than the messy "found parts" look-and-feel of the movies. I wanted this to be reflected in the proportions and materials of my custom pack. I also wanted the pack to have a realism to it - the RGB pack illustrations are "cartoony", lack many details, and often change from scene to scene in the cartoon. I took many creative liberties with my version and even borrowed a few movie pack details here and there to give the pack some scale and practical ruggedness.
For the material finish, I decided to experiment with "metallic" PLA colors - namely blue, gold, and silver. These are readily available on Amazon and for similar pricing as normal PLA colors (~$20 for 1kg spools) I found these materials give off a fantastic shine and have some excellent surface quality when they are printed. The smaller detailed pieces even have the look of a milled anodized metal if you're not looking too closely.
However, going into this the first print challenge with this type of material is it meant that I wouldn't be sanding and painting. Sanding metallic PLA ruins the finish and painting goes against the purpose of using these materials in the first place. Therefore, the parts needed to look clean right off the bed with minimal post-work. They also needed to fit together well so that doing any kind of gap filling measures with bondo wouldn't be necessary.
This brings me to another challenge - the Ender 3 print bed has a safe printable area of just over 7" cubed. This means that large parts like the cyclotron needed to be broken down for the bed and that seams between parts would need to be accounted for in the design. For example, on the cyclotron I eventually decided to create several interlocking wedges where the seams lined up with diagonal lens pieces. In my view, this strategy mitigates the effect of the seams and designs them in to the overall composition. Gotta roll with those constraints sometimes!
The other pack parts were more straightforward to model and print. I treated the red booster tube, gold canister, ion arm, and power gauge as discretely separate parts that could be joined together. Each of these pieces fit comfortably within the printer dimensions. Personally, I love the metallic red and gold materials - I am very tempted to try my hand at an Iron Man helmet as a future project!
To fit everything together, I used a combination of machine screws (various sizes) and gorilla glue. A light sanding between two peices of PLA combined with some gorilla glue produced a very strong bond between parts and the overall shell construction feels very solid.
Here are some various details of the pack - note the use of custom printed v-hooks, and fittings which are printed out of the PLA silver. You'll also see some of the installed switches and buttons which will be used in a custom electronics kit I am going to be designing with an Arduino.
Here are some pictures of the completed pack - minus a motherboard, custom electronics, and pack frame (I'm likely using an ALICE setup like the movie here).
I'll continue to add to this post to describe my process on the Ghost Trap and the Wand.
Of course if you want to know more about those items as well feel free to visit my Instagram page which has more process pictures
Check out my Ghostbusters prop builds and 3D printing efforts on Instagram @GhostbustersGear