April 8, 2014 at 10:57 pm #21714
Your method of using two shadows and a pointed light does indeed solve my issue. However, I found this method particularly finicky and I kept bumping the paperclip while trying to adjust things.
I’ve rigged up a way to use a cheap laser pointer to align the pen:
I have it hooked up to a switch so that I can turn it on and off without disturbing the lasers position.