Chuck jaw truing tool

[Paul Jones]

Thank you! Your chuck jaw truing tool is brilliant and easy to find the raw materials compared to other designs I have seen using round steel plates with holes precisely drilled to catch the chuck jaw edges. If you have time, I found it is a good practice to dismantle and clean the 3-jaw chucks before grinding the jaws to help ensure repeatable jaw clamping. It is amazing how much gunk gets into the scroll plate behind the jaws and can affect the jaw positions.

I too have turned the backplate register on my mini lathe chucks to be slightly smaller than what comes from the factory. These are bolt mounted so an easy modification and never found any slippage. The ER32 collet chuck now runs with almost no measurable TIR.The larger lathe and chucks have a D1-4 mounts and already run extremely true. However, I do use a 0.0001" division indicator to measure the chuck OD run-out after mounting to makes sure I didn't get a chip lodged on the D1-4 surfaces.

Thank you for sharing your designs and experience with chuck jaw truing.

Regards,

Paul