Round Stock Measuring Tool

thingiverse

This is a versatile measuring stock with expandable segments, each segment being 150mm long. You can easily add more segments and connect them securely using printed pins and an M5 bolt. For convenient mounting on a workbench, there are 5mm holes in the plate. By placing tabs into slots, you can achieve different measurements. My tests show that this setup offers good repeatability. The tabs reduce the length of the slot by 5-14mm, depending on their position. For instance, if you place the -9mm tab at 130mm, the usable channel becomes 121mm (130-9). A pen attachment was specifically designed for a Sharpie Ultrafine marker, but I discovered that many common markers taper, so this holder makes some compromises and won't fit over the entire length of the marker. To accommodate larger pens, I've also included a 12mm version. The center of the pen adapter is positioned 15mm from the edge of the segment. You're free to design your own attachments for the front or back if you prefer, and you can use this tool without any pen attachment at all. Note: The white-colored unit shown in the images is an older model, while the blue unit represents the current version.