Feynman brings up some problems with pantographs and precision in https://calteches.library.caltech.edu/1976/1/1960Bottom.pdf https://calteches.library.caltech.

Feynman brings up some problems with pantographs and precision in https://calteches.library.caltech.edu/1976/1/1960Bottom.pdf https://calteches.library.caltech.edu/1976/1/1960Bottom.pdf (page 6-7). I haven't thought about it myself, though.