school compass

thingiverse

This is the pen holder of a "Maped" compass. This integrate the pen holder and the nut. The original tread correspond to a classic M16x2. But I made here in the STL a metric pitch at 1.5. Anyway I also put the nut original nut with a metric pitch of 2, for those, like me, who lost it. I also attached the Freecad model. It has a parametric spreadsheet where you can change the metric step. Choose the step equal to 1.5 or 2 (recommended) and it will calculate and draw everything. You just need to export to STL and print it ! I do not encourage to use a step of 1mm, this is too small and this si quite difficult to screw the nut.... Use the 2mm pitch. I tried to print into 2 different positions. The "purple" position is easiest to print but has a real mechanical weakness in the top cylinder, because of the printed direction : it is very easy to break this small cylinder inside the compas because of the layers direction. Instead rotate it by ~90° like the gray one. In this recommended position the layer will support more torque. Otherwise, no need for suport. Use a raft instead of a brim (even if I used a brim for the gray one). at the first try (that break) I tried a large support (I used a brim of 4mm, inside and outside the model) but the base of the pen holder was a bit distorted, that block the nut when I try to screw it. Right after the print, the nut is hard to screw but after few time, it is then OK I used a H step of 0.12, to get a good quality. The total print does take around 1h30, not really long.