Gerber variable scale. 8:37 video by Chris Staecker.
https://www.youtube.com/watch?v=zeCslpB-JVU
Previously:
https://www.homemadetools.net/forum/...342#post173202
https://www.homemadetools.net/forum/...952#post156773
https://www.homemadetools.net/forum/...9580#post89618
https://www.homemadetools.net/forum/...960#post164306
