A good F3F competition plane deserves a good CoG setting, which requires the appropriate tool :) !
After testing and explaining the concept with 2 kitchen scales few months ago, and needing an excel spreadheet to obtain the CoG value, I wanted to reach the next level, and use one of the numerous digital CoG tools available on the market. Initially, I wanted to build mine and I had even printed all parts. But, I have too many thing in parallel, so I abandonned after this step, and ordered one when I saw this version, that is foldable, and personnalized ;) !
I just need to add some soft pad or rubber pad and it will be ready.
Many thanks to Kolosun Leung, and also thank you to the designer for sharing his work.