Ideas
Things I might build. Or might not.
Large-format 3D printer
Throwing ball
Space telescope
Shaper to CNC mill
An old Klopp shaper, turned into a CNC mill. Its heavy frame gives the stiffness; stepper motors go on the handwheel axes, a milling spindle on top. Speed hardly matters here: small cuts and slow feeds are fine if the machine can cut more kinds of work. Backlash is handled in software, by always approaching a position from the same side.
20 N rocket engine
A small rocket engine, about 20 newtons of thrust, to design, build and fire myself.
2000 °C furnace
A small high-temperature furnace: a chamber of about 10 × 10 × 10 cm that reaches around 2000 °C, with graphite shielding. For material and casting experiments.
Learning system
An app for learning from papers, lectures and exams, and for proving it. I read a paper, then write down from memory what I understood; it checks what is right, what is missing and what I got wrong. Exams work the same way. Minimal, calm, and built so that the knowledge ends up in my head, not in the app.
Hand engraving
Engraving metal by hand, the traditional way: gravers, an engraving ball, a leather pad.