thi is a remix of a 4 jaw chuck I found here https://www.thingiverse.com/thing:6399141 but it was for a 100mm 4 jaw chuck and I resized it so it fit my chuck sanou k11-125mm 3 jaw chuck and also my 4 jaw chuck this model is still under construction but it works like that

in the 3mf it is in draft 0.28 because it was a test but next one will be slower and better and I will update the 3mf

if you need soft jaw for your 125mm chuck I made some here