Free formed circuit protected by a brick of crystal clear resin

The look of this crystal clear resin brick is pretty amazing. [Rupert Hirst] decided to encase his amplifier circuit in a block of polyester resin. We just hope he got everything in his circuit right because there’s no way to replace any of those parts now!

He deserves a lot of credit for working out a visually pleasing way to mount each component. There wasn’t any type of substrate used, but a few lower gauge wires were picked as the rails and they add some mounting stability. Before casting, he took the case of each of the three jacks apart and sealed the seams with some of the casting resin to prevent the final pour from filling them up.

Eagle CAD was used to design the mold. He printed it out on some card stock, then used a hobby knife to cut the pieces out and super glue to assemble them. A second layer of super glue was run on each seam to ensure they’re water tight. After the casting was made [Rupert] spent plenty of time sanding, routing, and polishing the brick to achieve this look.

This makes us wonder about heat dissipation. Do you think it will be a problem? Tells us what your opinion by leaving a comment.

A six-year adventure into the world of CNC fabrication

Hackaday doesn’t always get the entire back story of a build. The usual assumption is that someone decided to build something, and with just a little bit of effort the project makes it into the Hackaday tip line. This doesn’t do justice to the builder, with skills honed after years of practice and experience. A 200-word summary is deceiving, and makes everything look almost too easy. [Michal] decided to buck that trend and sent in his half-decade long adventure of becoming one of the best micro-scale machinists we’ve ever seen.

In 2006, with years of robots made out of hot glue and cardboard behind him, and the quality of 3D printers not up to his exacting specifications, [Michal] snapped. He sunk the better part of $3000 into a Roland MDX-15 desktop mill. After several months of futzing about with acrylic sheet, [Michal] came across the wonderful machining properties of modeling board.

Determined to do something useful with this modeling board, [Michal] started looking into resin casting. Casting in resin is a common technique in the artist and model maker communities to mass produce small plastic parts. After getting his hands on eight liters of polyurethane resin, [Michal] made a useful part guiding the direction his skill set would grow in the coming years.

After years of experimenting with techniques, materials, and mediums, [Michal] eventually honed his craft and was able to finally start building real robots. These projects were a far cry from the cardboard and milk jug contraptions made earlier in his career. [Michal] was now producing incredibly precise gear assemblies with accuracies within 0.002 mm.

You may remember [Michal] from his robot with pivoting wheels we showcased last week. He got a lot of email from people wanting to know how to start delving into his unique blend of artistry, engineering, and craftsmanship. The good news is you can now learn from his mistakes, so a planetary gearbox shouldn’t take more than a few months to finish.

Who needs mecanum wheels?

Skills are all that’s needed to solve a problem. Take this four-wheeled robot as an example. [Michal Zalewski] wanted it to be omnidirectional but wasn’t very satisfied with the concept of mecanum wheels and the like. So he designed a chassis with wheels at each corner that can pivot as one to change orientation. The image may look like a rendering at first glance, but this is actually the physical prototype. See what we mean about skills?

Okay, so the robot design is pretty cool. But we’re more excited about the build process. We’ve looked at [Michal’s] work before. He wrote a thorough guide about CNC mold making. These parts are all cast from epoxy. This starts with a rough milled mold, which is given a second pass for the fine details before being painted with a release agent and used to make a silicone mold. From this the parts are produced. Check out the Flickr set showing the casting process for the planetary gear box on each motor. If only these results were as easy to achieve as he makes it look.

[via Reddit]