This is a useful scribing block with an adjustment mechanism of the needle point height.
This design came from a famous Japanese mini-lathe technical guidebook. It incorporates both coarse and fine adjustments which makes it convenient to use.
The overall height is about 12 cm which is adequate for my work.
Put needle cap, made of silicon rubber pipe, when it is out of use.
For safety, protective tubing is placed over needle when not in use.