My Digitac pal Uwe Reisinger could not be stopped to help me with the pen for the public presentation. Lasers are way too dangerous to expose the radiation publicly. Therefore he built a penholder head which will be connected instead of the laser module. Uwe is a maniac in hacking. Give him a box with scrap parts and he will do something useful with it.

For the pen holder he used an old relais a threaded rod a copper pipe and some screws. A spring balances the axis, so that the relays is strong enough to move the pen up and down. The pen will be clamped into the pipe which makes it possible to adjust the height anytime.

If there's enough time at friday, I will provide a short video for you to see it in action.