best chisel sharpener

I have tried many different sharpeners but this one is the most convenient because of the dovetail, but there were not enough magnets to hold the chisel while tightening the screws.
magnet used is 5mm in diameter (in fact 4.9) and 4mm high (in fact 3.9).

thanks to the author
https://www.thingiverse.com/thing:4799989