Kappeler was born in Frauenfeld. In 1927, he graduated as a mechanical and electrical engineer from the ETH Zurich. He became an engineer and later a partner in the company Emil Pfiffner & Co in Hirschthal and, from 1940, its chairman of the board of directors. His love of the mountains led him not only to undertake mountain and ski tours, but also to produce a relief. For almost 25 years he devoted his free time to the Alpstein relief. With walks in the terrain, by means of a pantograph constructed by himself and other instruments, he optimized the production of the relief.

[1] This article bases on Mair, Toni. Grieder, Susanne. Das Landschaftsrelief – Symbiose von Wissenschaft und Kunsthandwerk. Mit Schweizer Reliefkatalog. Verlag hier+jetzt. Baden, Schweiz. 2006. S.161.