This idea comes from my kitchen and bathroom remodeling bag of tricks. I've been making these for nearly 30 years.

To purchase PVC online: go to Amazon or Ebay and do a search of "Rigid PVC white flat sheet 1/8"" Beware that there is a corrugated and a foam PVC board. You don't want those. You want solid, machinable flat stock. 👍

Here's a link to my video showing how to make small circles with a table saw:    • How To Cut Small Circles With A Table...  

Here's a link to my video about the PVC carpenter's square:    • Introducing The Remarkable Whizbang C...  

Here are Amazon affiliate links to tools shown in this video...
Irwin Unibit #4 : https://amzn.to/3Uid32l
Deburring tool: https://amzn.to/3xx6kZk