Hand machined mechanical pencils

V3 pictures of construction





1) Overall layout of the laser. The two headstocks can be seen along with the copper cooling tube.

2) A nice little temperature gauge I found in the skip at university. Unsurprisingly, it works! I use it to measure the cooling water's temperature. It rises by about 10 degrees in the 20mins I ran it continuously. That's the probe I'm holding on the left. It runs of a little solar panel so it never needs batteries!

3) My Pirani Gauge setup

4) An assortment of my various pressure gauges