Round Stock Measuring Tool

This is an extensible round stock measuring tool. Each segment is 150mm long. You can print additional segments and connect them with printed pins and an M5 bolt. There are 5mm holes in the plate for mounting to a bench. You can place the tabs into the slots get different measurements. There is pretty good repeatability in my tests. The tabs subtract 5mm to 14mm from the slot they are placed in. For example, if you place the -9mm tab at 130mm, the usable channel is 130-9=121mm. The pen attachment was designed around a Sharpie Ultrafine marker. I looked at several common markers and they all seem to taper, so the holder is a compromise and will not fit over the entire length of the marker. I have also included a 12mm version for larger pens. The center of the pen adapter is 15mm from the edge of the segment. You could design your own attachments for the front or back if you desired. You can also use the tool without a pen dapter.

Please note that the white colored unit in