@Jeremie_Francois I finally got around to reading the whole post. GREAT work! You are really showing your technical ability by skipping the Arduino code on the slave and making use of interrupts for better control. Kudos! Also, nice work on the improvements–you saved me some typing.
For now, I’m still using an induction sensor and software compensation on my Printrbot LC+ v2, which works well enough, but I’ve really been wanting to build a printer that only moves the bed in the Z-axis. I know the UM1 uses laser cut panels, but you have me wondering if I should try to make them on my OX CNC. I will probably not do that because I’ve been eyeing an aluminum extrusion version of the Ultimaker (e.g. Eustathios) for quite a while, but still…this just makes me want an Ultimaker even more! Again, great work!