PCBrule

Story

I was a freshman in high school when I first learned what a slide rule was. My FIRST robotics mentor brought a slide rule to a meeting one day and I was blown away by the magic math stick and what it could do.

I’ve always been attracted to purely mechanical things — I love analog photography because I find it really neat that you can produce an image using only gears, curtains, levers, glass, and chemistry. My favorite school supply throughout high school was a cherry red DigiKey PCB ruler — there was a satisfying quality about the gold lettering and just how durable it was.

Since then, I’ve had a nagging idea in my head: “Wouldn’t it be awesome if you made a slide rule out of Printed Circuit Board?”

Now as a student in university I am finally acting on that idea — and it is pretty awesome in my opinion.

Inspiration

“If you’ve had this idea for a while, what pushed you to actually make it?” you ask.

Well it’s simple. I am a student in a competitive field. I wanted to make a really cool and memorable “business card” that I could hand out at my school’s career fair. I was hoping this memorable object would sit on a company recruiter’s desk with my name on it, and they’d see it, and give me an internship.

Selling them and bringing it to market was mostly an afterthought.

Wait, what’s a slide rule?

A slide rule is a mechanical calculator — engineers used them before the advent of digital computers. It is a tool that operates on the principle of adding together logarithms.

The Apollo astronauts carried a Pickett N600-ES to the moon, and the PCBrule is modeled after that very same design — with identical scales and calculation capabilities. Its layout has been time tested and literally approved by NASA.

Current Prototype Demonstration

Upcoming Prototype Iterations

• Mechanical redesign of cursor guidance system — Engineering cursor rails and guides to eliminate acrylic surface contact
• Polycarbonate window prototyping and testing — Sourcing and machining polycarbonate alternatives for durability testing
• Friction and smoothness optimization — Testing different materials and coatings for optimal slide feel
• Long-term durability testing — Stress testing the updated design for wear patterns and reliability
• Shim manufacturing jig — Developing a jig to assist in punching and cutting of 0.1 mm stainless steel shim pieces
• Bow spring bending jig — Making a device to repeatably and consistently bend the phosphor bronze cursor springs