I designed this simple part to help me hold a filler board while I trace the upper contour in order to fill the gap between the carcass of a cabinet and my uneven ceiling. To be used with standard 19mm boards. I printed it on my Kobra S1 using PETG. The .3mf file contains also 4 discs with pre-drilled center hole (may be drilled further based on size of your pen tip) to obtain a gap of 1, 2, 3 or 4mm between the ceiling and the line being drawn. The latest version is slightly more bulky than on the picture, to make it stronger.