This Kinetic Art Display Uses A Gin Bottle

[David McDaid] likes gin. So in homage to their favourite tipple, a certain brand of Scottish origin, a kinetic art project was brewed. Tabled as a Rube Goldberg machine — it’s not — but it is a very smart marble run type installation, dripping with 3D printed parts and a sprinkling of blinkenlights.

The write-up shows the degree of pain we go through with building such contraptions, apparently [David] burned through 2.5 kg of PLA filament despite the bill of materials requiring a mere 660 g. Much experimentation, trial and error, and plenty of print-and-reprint-until-good-enough, resulted in a clean looking run with some neat features. We particularly like the use of a stainless steel jigger to add a touch of metallic ting, to the soundscape produced. The whole show was put together in Fusion 360, since all those tight tolerances do not make for a simple construction without a lot of fiddling around with the layout. Once it was a sound, layout was prototyped on a wood board, which was subsequently used a drill template for the final acrylic version.

On the electronics side of things, an Arduino Nano clone is on control duty, reading an IR trip sensor to fire of a simple light effect, illuminating the gin bottle in a slick fashion. These machines need a mechanism to raise the balls against that pesky force of gravity, in this instance a 3D printed custom chain was constructed, driven with a stepper motor in turn driven from a TMC2208. You see, this thing lives in the kitchen, so the aim was to keep all the noise from the mechanics to a minimum so only the noise of LDPE balls rattling around can be heard. They are the star of the show after all! The build looks nice and would certainly be something we’d like to see on the wall. Obviously we’ve seen a few marble runs over the years. Here’s an interesting one that uses an elevator mechanism, and another project that shows how to generate runs procedurally.

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Custom Inflatables Are Only A Laser Beam Away

Carl Sagan one said “If you wish to make an apple pie from scratch, you must first invent the universe.” It might not be a very accurate description of the relative difficulty level of baking, but the logic is sound enough: there’s often a lot of ground work that needs to be to covered before you hit your ultimate goal. A perfect example of this principle is the inflatable raft that [ralph124c] hopes to eventually create; before he can set sail he has to perfect making balloon animals with his laser cutter.

In the long run, the raft will be constructed from sheets of TPU coated fabric that are fused together with a hot iron. But before he spends the time and money on building the real thing, he wants to do some scaled down tests to make sure his design works as expected. He makes a cryptic remark about learning the hard way that inflatables are prone to bouts of strange behavior, and out of an overabundance of caution we’ll just take his word for it.

He hoped to test his designs with the much cheaper LDPE film, but he found that the hot iron didn’t fuse it together in the way he was hoping. His mind turned to his 60 watt laser cutter, and wondered if the desired effect could be achieved by turning the power down as low as possible and quickly moving across the material.

His first attempts either blew right through the film or did absolutely nothing, but eventually he had the bright idea to move the laser farther from the LDPE. This put the beam out of focus, which not only expanded the area it would cover, but reduced the energy being delivered to the surface. With a bit more experimentation, he found he was able to neatly weld the pieces of material together. He even found that he could increase the power slightly to cut through the film without having to adjust the laser focus. With the ability to create complex inflatable shapes, perhaps [ralph124c] will create balloon version of Carl Sagan or an apple pie to celebrate.

Of course, this technology isn’t limited to birthday balloons and model rafts. The ability to quickly and easily produce custom inflatable shapes could be a huge boon to anyone working in soft robotics, and we’ve even seen similar concepts applied to haptic feedback systems.

[Thanks to Arthur for the tip.]