# Replacing the Numbers on a Cuckoo Clock Dial

A while ago I bought a beat up cuckoo clock on eBay, to practice cuckoo clock cleaning and repair. Its face was missing most of its numerals. In this post, I describe how to use a 3D printed template to glue the numerals on a cuckoo clock’s face.

Continue reading Replacing the Numbers on a Cuckoo Clock Dial

# Geometry, Gothic Architecture, Rose Windows, and Christmas Ornaments

(first published on Needhamia.com in 2007)

I find the rose windows of Gothic cathedrals awe-inspiring. From the rigid formalism of Chartres to the flamboyant explosion of Tours, their marriage of geometry, philosophy, and aesthetics with stone and glass is awesome. Built at a time when science and spirit weren’t as divided as today, each window is a statement of the beauty, order, and harmony in the world. Using only a pair of compasses (dividers) and a straight-edge (an unmarked ruler), the Gothic architects created myriad lace-like designs, making stone hang in the air and glass sing.

Geometry was my favorite math class in Jr. high school, and the Euclidean constructions that I drew with my compass and ruler I later applied in shop class and drafting class. Geometry was mathematics made beautiful, and I loved it.

Continue reading Geometry, Gothic Architecture, Rose Windows, and Christmas Ornaments

# Build a Minimal Weather Underground Station

Today’s post is a How-To for a project I recently completed: a temperature-only Weather Underground Personal Weather Station made from an ESP8266, a MAX31820 temperature sensor, and a few miscellaneous parts. The whole project fits inside a 3D printed project box for mounting on an exterior wall that is sheltered from the weather.

Continue reading Build a Minimal Weather Underground Station

# How to Play 25 Lotus Flowers

25 Lotus Flowers is a  rotating-piece puzzle I recently invented (at least I’m ignorant of any earlier versions). The object is to turn the 25 lotus Flowers to form a given pattern. The challenge is that each Flower prevents one of its neighbors from turning, so you usually have to turn several Flowers before you can turn the one you want to turn.

Continue reading How to Play 25 Lotus Flowers

# Lunar Clock: Designing a 3D Printed Clip

In my previous post, I replaced the electronics of my several-year-old lunar clock design with modern parts. In this post, I’ve replaced the laser cut parts with 3D printed parts, with particular attention to the clip that holds the photo interrupter in place.

Continue reading Lunar Clock: Designing a 3D Printed Clip

# Well Depth Sensing: Mechanical Design

In my previous post, I finished the Web Service that the ESP8266 uses to upload well tank temperatures (and eventually a depth estimate) to a cloud database. In this post, I turn to the mechanical design of the case for the RJ45 jacks for the 1-wire interface.

Since my last post, I’d ordered and received some RJ45 jacks and breakout boards from Sparkfun.  I’m planning to use an RJ45 jack on a half-sized breadboard as the interface between the ESP8266 Thing Dev board and the 1-wire bus.

Continue reading Well Depth Sensing: Mechanical Design

# My First 3D Printed Sundial

I’ve been interested in sundials for ages.  Tracking the sun’s path by observing the shadow of a stick is an ancient form of astronomy, and a gateway into geometry (literally “measuring the earth”).

Continue reading My First 3D Printed Sundial

# Dog Weight Scale Part 12: More 3D Printing

In my previous post, I did a little woodworking on the scale.  In this post, I start designing a 3D printed part that will keep the top of the scale centered on the bottom.

Ever since I measured the center of gravity of the top plywood circle, I’ve been puzzling through how to make sure that center of gravity stays centered on the bottom part of the scale.  Without some sort of connection between the top and bottom plywood circles, the top will inevitably slide over time, messing up all the center of gravity calculations.  On the other hand, if this connection between the top and bottom has much vertical friction, it will take some of the load of the scale, throwing off the weight calculation.

Continue reading Dog Weight Scale Part 12: More 3D Printing

# Dog Weight Scale Part 10: 3D Printing Load Sensor Holders

In my previous post I soldered the weight scale parts to a proto-board.  In this post, I design and 3D-print the part that keeps the Load Sensors from slipping.

The Load Sensor is an oddly-shaped thing that has a few tricky constraints: the T-shaped part in the middle must be free to bend downward (my wooden mounts take care of that), and I don’t want it to slide out of place horizontally or tilt off of its position when I’m putting the top plywood piece on the scale.

I’ve tried a couple ideas – wood holders, washers and bolts – but nothing seemed to work well. So this week I decided to learn how to design and print 3D parts.

Continue reading Dog Weight Scale Part 10: 3D Printing Load Sensor Holders