We’ve all seen the exploded view of complex things, which CAD makes possible, but it’s much harder to levitate parts in their relative positions in the real world. That, however, is exactly what [fellerts] has done with this wristwatch, frozen in time and place.
Inspired by another great project explaining the workings of a mechanical watch, [fellerts] set out to turn it into reality. First, he had to pick the right watch movement to suspend. He settled on a movement from the early 1900s—complex enough to impress but not too intricate to be impractical. The initial approach was to cast multiple layers that stacked up. However, after several failed attempts, this was ruled out. He found that fishing line was nearly invisible in the resin. With a bit of heat, he could turn it into the straight, transparent standoffs he needed.
Even after figuring out the approach of using fishing line to hold the pieces at the right distance and orientation, there were still four prototypes before mastering all the variables and creating the mesmerizing final product. Be sure to head over to his site and read about his process, discoveries, and techniques. Also, check out some of the other great things we’ve seen done with epoxy in the past.
Surely there is a better photo of the piece?
Many good photos on the website linked.
If you want to see some epic modelling and casting, check out https://www.youtube.com/watch?v=ei1z6UgRaU0 – the maker also does some embedded LEDs in his models for explosions – https://youtu.be/ATKUT4eNL6E?si=_IxYbGJIjcMDeFfl&t=1077
My initial guess before reading was multiple pours, separated by time. I haven’t experimented with epoxy to know if you can get an invisible edge by pouring on to partially cured material.
IME multipour works better with acrylic than epoxy
My dad made one of these in grade school about 50 years ago (minus the clever arrangement; parts were just sprinkled in). Not sure how much epoxies have changed since then, but there are definitely visible “layers” to it which are visible from certain angles.
Shades of “Tomb Raider”
I wonder if that would be possible to use the same resin to cast little parts that would replace the fishing line, and if they would become totally invisible once cured.
Ive had good luck using acrylic to cast holding fixtures before overcasting with the same acrylic, so long as the fixtures were well polished and cleaned. With both polyurethane and with epoxy separately Ive not been able to avoid a visible interface between castings no matter what Ive tried. YMMV
Author commented on hacker news on this:
“I tried casting thin rods out of epoxy to replace the nylon but failed to achieve a good result.”
Essentially every comment I see with people trying to improve it, the author has tried and had bad results.
Within the writeup the author states that he chose to use vacuum alone, despite being aware that pressure is often recommended for clear castings. So even by his own admission he did not try all possibilities before landing on something that worked to his satisfaction.
I see no indication that the author made any attempts using any materials other than epoxy. So mentioning my own struggles with both epoxy and polyurethane, and my success with acrylic seemed relevant. Epoxy is a thermoset resin, as such it is less forgiving than Acrylic, which is a thermoplastic. The chemical reactions that happen during epoxy curingcreate permanent crosslinked structures. When you cast new epoxy over cured epoxy the new material does not form molecular bonds with the old material. With Acrylic the monomer of the new material breaks some of the crosslinked molecules of the previous casting and chemically bonds to it. This is why its so popular in orthodontic and prosthodontic appliances. Its easily and cleanly repairable.
Author here. You’re right, I never tried acrylic for this project. Epoxy is much more available in my area and there seems to be a lot more information about (clear) epoxy casting online than for acrylic.
I am curious though, do you have any good resources for clear-casting 6x6x15 cm-ish cubes in acrylic? I mostly find AI generated slop or people mistaking epoxy for acrylic when searching.