Center Marker Finder / Gauge / Template, 90 & 45 Degree Square & Protractor, for Dowels, Square Stock, etc. - UPDATED: 6 Slots Widths

UPDATE 2025-05-19: I have added 50mm high versions of the 3mm walls models. This makes the tool usable on objects with some unique or non-flat end surfaces.

UPDATE: I have updated this design to include 6 different slot widths for both of the different wall thicknesses, making twelve models in total. As mentioned below, the original design accommodated a .09mm lead/tip; the slot is 1mm wide. I have added models with 0.6mm, 1.5mm, 2mm, 2.5mm & 3mm slot widths to accommodate thinner and wider marking instruments. To allow for the wider width slots, I reduced the diameter of the two front circles, though this has minimal effect on the functionality (just an FYI).

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This is a center finder/marker tool for end stock (dowels, boards, pipes, etc.); with additional functionality as a 90 degree square and simple 45 degree protractor. There are two versions: 2mm (light weight) or 3mm (stiffer) walls & face. The 3mm version side walls are 2mm taller, for more rigidity and contact with the stock material. These are designed to be used with a mechanical pencil (=/< .09mm lead) or a fine tip marker (Sharpie).

Both versions have the same capacity; with circular and square stock, center marks can be made on objects with maximum diameters up to ~150mm (~6"). 45 degree angle lines can be drawn across objects ~70mm (~2.75") wide.

Both tools have rough edge clearance channels and corners to help with messy edges from previous cuts. See pictures for more detail.

The tool stands upright on its side for checking square and 45 degree angles.

If you are looking for additional uses for this tool, I guess if you were desperate, and you have some string, you could use it as a plumb bob as well, though it is not very heavy.

2mm Version Dimensions: 80mm x 80mm x 10mm (~3 x 3 x .4"); ~8 grams/2.72 meters of filament @ 100% infill.

3mm Version Dimensions: 81mm x 81mm x 13mm (~3.19 x 3.19 x .5.12"); ~14 grams/4.67 meters of filament @ 100% infill.

The pictures are of the 2mm_Wall_x_1mm_Slot version (100% infill), the first one I designed. It worked fine the first time I used it on all of the different materials, but I wondered if a stiffer version would work better. I made the 3mm version and I prefer it. I figure that if I am going to print a tool that I will use in my workshop for a long time, why skimp on a few grams of filament? Both versions have a hook hole for hanging on a nail or on pegboard.

Category: Hand Tools