Behold a DIY, Kid-Friendly Table Saw

The “table saw” swaps the saw for a nibbler; here it is cutting corrugated cardboard in a manner much like the saw it replaces.

“Kid-friendly table saw” seems like either a contradiction, a fool’s errand, or a lawsuit waiting to happen; but this wooden table saw for kids actually fits the bill and shows off some incredible workmanship and attention to detail as well. The project works by using not a saw blade, but a nibbler attached to a power drill embedded inside.

Unsurprisingly, the key to making a “table saw” more kid-friendly was to remove the saw part. The nibbler will cut just about any material thinner than 3 mm, and it’s impossible for a child’s finger to fit inside it. The tool is still intended for supervised use, of course, but the best defense is defense in depth.

The workmanship on the child-sized “table saw” is beautiful, with even the cutting fence and power switch replicated. It may not contain a saw, but it works in a manner much like the real thing. The cutting action itself is done by an economical nibbler attachment, which is a small tool with a slot into which material is inserted. Inside the slot, a notched bar moves up and down, taking a small bite of any material with every stroke. Embedding this into the table allows for saw-like cutting of materials such as cardboard and thin wood.

The image gallery is embedded below and shows plenty of details about the build process and design, along with some super happy looking kids.

Continue reading “Behold a DIY, Kid-Friendly Table Saw”

The Nibbler: a 4-bit CPU built with 7400 logic

nibbler-schematic

Maybe we shouldn’t say “built” since [Steve Chamberlin] hasn’t actually heated up his iron yet. From the finished schematic above that is puzzling at first, until you realize the scope of the project. His Nibbler implements a 4-bit CPU using 7400 logic chips. Because he’s come up with the architecture himself he’s taking a lot of steps to check all of his work before committing to a PCB.

We linked to his category for the project which is still in progress. Most recently he wrote a program to prove that it’ll run on the hardware. That’s a feat considering this is still just a design idea. It was made possible because he wrote a simulator based on the design. The C++ tool simulates data and control buses and features a full set of debugging tools.

Careful testing of the design before the build is the best possible way to go. The simulator and debugging tools will be useful for software development even after the hardware is built. And testing before wiring is a must as these things get out of control quickly in terms of soldering complexity.

[via Dangerous Prototypes]