The Bottom Cap

A project log for Automatic Chessboard

Making my own automatic chessboard

Carlos Lopez PCarlos Lopez P 05/15/2021 at 16:390 Comments

There should be a smooth interaction between the board’s surface and the pieces. To get around this, we are looking at different materials to cover the bottom part of each piece. The aspects I want to solve are:

  1. Avoiding the natural veneer from wearing out because the repetitive movements the pieces will perform over the board.
  2. Avoiding leaving stains over the surface caused by the bottom cap, so it must be made out of a durable material
  3. The friction between the pieces and the surface must be minimal to achieve a seamless motion
  4. The bottom cap should be very thin (around 0.5mm) to have the minimal distance possible between the magnet from the piece and the magnet on the arm

After searching for similar problems and how friction, heating, wearing, etc. were solved...right away I knew the materials to test would be: HPTFE, PTFE (Teflon), felt, silk and the looped female side used on velcro.

On the board’s side, the veneer surface is covered with Epoxy varnish, because it’s the most resistant treatment I could find to protect the wood without losing its natural qualities.

Tavo helped me to build a small jig to test all these materials. It consists of a magnet arm directly connected to a stepper motor that drags a piece over a small veneered board (15cm x 15cm).

The jig drags the piece 5cm per movement and it reaches over 85,000 movements per day. We did the maths and this way we can emulate 4 years of use in only 3 days!!!

We are still not sure about which material should be the selected one, all of them presented different issues regarding wearing and aging so we are still looking for new ones to test.

Some of you recommended some materials in the comments, we already ordered samples of them and I’ll let you know how they work. Any other materials you think we can test?

I’ll leave our discord server if you would like to chat about this project:

And my YouTube channel in which I upload progress and test videos: