Proxxon Shaft Lock for flexible shaft 110/BF or 110/P

Since years I use the Proxxon MICROMOT Flexishaft 110/BF. I like the shaft because it is so light compared to the strong but bulky drill / grinder IBS/E. It allows precise tooling due to the dual ball-bearinged milled steel shaft. However, the flexishaft has *_has no shaft lock button_*. You have to use a dowel, a drillbit or sth similar to block the steel shaft when you tighten or loosen the drill chuck, which always annoyed me. Therefore I designed this simple clip-on part. It clips right on t