Week 11: Mechanical design, machine design

In the mechanical and machine design week, my fabmate Pedro Chana and I made a solar wood engraver (Solaser), using fressnel lens to generate enough heat to engrave the wood. The process and results were amazing and documented here.

Note: as we were only 2 people, we 100% worked together during the week. Its very difficult to pull apart one work from another. I supervised more the building part and Pedro supervised more the documentation, but both worked together on every part (design, making, programming, testing, documentation) of this amazing process. 

Apart from the documentation we have, I'd like to highlight some learnings:

1-We thought that the process was going to be really slow, so a solar tracker could be needed to maintain the focus. But the reality is that we are able to engrave at 10 mm per second. The conclusion is that if the drawing is not very complex a manual tracker (as we did) is enough. 

2-On the other hand, as the power of the focused sunlight is very high, the machine can't be stopped easily, because just one second with the machine stopped can make the wood burn. So it would be very useful to have a device to stop the sunlight, with two options:

  1. A mechanical device: Perhaps with a servo motor putting some piece on the way of the sun rays.
  2. An LCD screen to electronically switch the rays on and off.

3-The perfect complement for the Solaser machine is a solar panel for the power supply. It's obvious that you need sun to run the machine, so you have it also to power it. We didn't have time to do it but we plan to do it soon.