Soon after purchasing a CNC lathe in 2020, I designed and produced my first line of CNC precision spinning tops, the Cahaba series.
The series is comprised of 4 variations of a simple, elegant design intended to maximize the spinning time for a top that is small enough to fit in a pocket and affordable for the everyday top lover. The variations differ only in the design of the body; specifically, the number and location of grooves that give the top its distinctive appearance while spinning.
These 4 tops look great as a full collection, but can also be purchased individually.
The Cahaba name
This top is named after the Cahaba River, a major tributary of the Alabama River and part of the Mobile River basin. It begins near Birmingham and travels 194 meandering miles southward.
The Cahaba River is many things to many people, including:
- An endless supply of entertainment and relaxation for kayakers, anglers, floaters and others who head to the river for recreation.
- A source of drinking water for 20% of Alabama residents.
- Home to more species of fish than any other river of its size in North America.
The Cahaba top and the Cahaba River also share a name with the Cahaba lily, or Hymenocallis coronaria. Cahaba lilies are a beautiful white flower and are a well-recognized symbol of Alabama’s natural beauty. They grow in the Cahaba River, as well as in other parts of the Southeast US.
There are cocktails and hotel conference rooms named after the Cahaba. There are even festivals celebrating this lily. Unfortunately, the Cahaba lily is currently endangered due to dams, though there are ongoing efforts to protect it and increase its populations.
Cahaba top specs
A Cahaba top weighs between 3.5 and 4 ounces, with slight variation depending on the version. It is 1.9 inches tall and 1.7 inches in diameter.
It is made from an aluminum core and a stainless steel body.
Why two different metals? It makes the top spin longer! Learn why in my article about the basic physics of spin tops.
The point at the bottom of the top is a hardened and ground ball bearing that is pressed into the core. This prevents the point from wearing down over time with use.
The spinning stem is finished off with a diamond knurl grip to help the user get a good, hard spin.
I’ve saved the best spec for last. The spin time! The Cahaba spins for over 10 minutes on a smooth, flat surface if given a powerful spin. My best spins with this top have been over 13 minutes, though this may not be attainable for novice top enthusiasts.
Design and manufacturing
This series of tops was one of the first things I manufactured on my CNC lathe. A very simplified version of the production process is this:
- I write and input a program into the machine.
- A piece of cylindrical stock is placed into the lathe.
- The lathe executes the program.
- I assemble the top components, including the core, the body, and the tip.
A single top requires four main machining operations: two for the core and two for the body. This is because the lathe must hold on to one end of the part while the other end is being machined.
One of the great things about a CNC lathe is that many of the same part can be produced in a relatively short period of time, since the steps are programmed into the machine. Nonetheless, each top needs to be inspected and tested by hand, as mistakes, flaws, and other unexpected things occasionally happen.
The Cahaba in action
The video below is a short demonstration of a “flock” of Cahaba tops spinning together. It does a nice job of illustrating how evenly balanced they are, though doesn’t show the true extent of their spin times. A video showing a the full duration of a spin would be over 10 minutes long!
You can view more of the Cahaba top in action (as well as my other tops) on the Scovie YouTube channel.
Get your very own precision spinning top
A Cahaba spinning top belongs on a desk, in a purse or pocket, in a top collection, or on a display shelf. Get yours today from our top shop!