Something I have done for drawings and diagrams, published in the journal under the heading “Club home of the masters”. In one of the rooms was a note on the machine to edit used caps from glass canning jars. I use a similar device for ten years, and it has never failed me even once.
In my fixture and differences that provide additional opportunities. First of all, the versatility: with a roomy ring the holder can edit the different size of the cover. Made on pivot arm guide wheel pressed by the inside of the holder, providing its rotation, run-in and alignment bent or deformed can opener the surface.
The design of The device is extremely simple. Those who wish to manufacture these, I want to give some explanation and recommendations.