Reparing coarse adjustment knob on HP-105B

[tkamiya]

I just went through a process of experimenting and repairing a fiber glass shaft extension for 11801 adjustment on HP-105B.  Mine was there but the fiberglass shaft was so damaged by heat that it no longer functions as needed.  A little metal tab that acts as screw driver blade at the tip of fiber glass piece has come completely loose.

I went through iterations but what finally worked was to cut off the original piece and glue in a tip harvested from ceramic tip screw drivers.  I used this screw driver for parts.  A small hobby lathe was used to drill a coaxial hole onto fiber glass shaft.  As attached image will show, the finished part is a little shorter than the original, but it still works well.

https://www.ebay.com/itm/ENGINEER-DA-72-Ceramic-Driver-0-4x2-4mm-Stock-in-USA/172416675691?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Please see