To start off, here’s what we’re talking about. You’ll want sound enabled for it.
This second attempt at a replica jetpack was also 3D printed (on a Bambu Lab P1S) using PETG filament, sanded and painted to achieve a metallic-looking finish. The 3D model was the “Veepy Jetpack” design, which is sadly no longer available. I am stunned at how well-designed this model is, not just in terms of being screen-accurate, but also how well things are engineered to support successful printing and assembly. There are even aspects that facilitate maintenance of it, something that I tried to continue in other areas of the build. The model was also designed to accommodate effects hardware, in order to provide lights and sound and a moving fan.
The Veepy design also incorporates off-the-shelf hardware components when possible, for things like the flap actuator parts, the braided hoses and copper pipes on the engines, the fan, and hundreds of tiny rivets. Having the rivets be a separate component not only made them look more realistic, but it made the sanding process easier without having to work around hundreds of little bumps.
To make maintenance easier, the nose cone sections are held in place with magnets, and can be carefully pried off. That gives access to the inside of the tanks (if your hands are small enough). The engines rest in a bracket inside the tanks, and are secured with a single screw each to keep them from popping out of place. Removing that screw makes it possible to remove the entire engine, at which point the tank is empty. The tanks are attached to the central section at the bottom by some 1/4″ screws, and at the top there’s a long threaded rod running from one tank to the other, through the radiator section. Those parts are designed so that once the nose cones are removed, you can unscrew the nut from one end of the threaded rod, slide it over to the other tank, and pull out the radiator. At that point you have access to the central section from the top, which is useful since that’s designed to contain the effects electronics.
I took things a step further and worked to keep the tanks separable from the central section if necessary. The little rivets are all super-glued into place, but the ones that would connect the central piece to the tanks are only glued to the central section. That made the tanks separable, but it would leave a small gap visible between the tanks and central section when things flexed at all. To counter that, I removed a handful of strategically-located rivets and replaced them with threaded fake rivets that can be secured from both sides. These are normally called Chicago Rivets, and I found some that worked for it, but installing and removing them was really fiddly. So instead I took some long-ish M3 stainless steel screws, filed the heads down until they looked like the rest of the rivets, and secured them with wingnuts on the back side. Now the tanks are securely attached to the central section, but I can undo that part and remove them if needed.
I think the only other tweak I made to the Veepy design was to replace a couple of threaded wood inserts with head-set inserts, because I was afraid the wood inserts would end up breaking the 3D printed plastic. Regardless, the Veepy design was incredibly impressive, and it inspired me to put in the extra effort necessary for other aspects of the project.
It’s worth noting how much detail the Veepy model puts into parts that generally won’t be seen: Here are the engines, which are mostly covered up when installed in the tanks:
The braided steel hoses are real, along with the brass compression rings on them, and the copper pipes. I didn’t have a proper tool for bending the copper pipes, so I used a dremel tool to cut a bunch of slots partway through the pipe in the areas when it needed to bend, which made it possible to bend it without just folding the hold thing flat.