It's an adjustable compass for drawing that uses an iris mechanism. It also has a straightedge for drawing lines. This is the second version I've made of this and it fixes some tolerance issues with the original design. The design is my own, but I took inspiration from the following iris compass linked below. My design is quite a bit thinner, although it may not produce the most precise circles.

• [https://makerworld.com/en/models/60163-iris-compass-circle-drawing-remix-with-small-impro?from=search#profileId-62315](https://makerworld.com/en/models/60163-iris-compass-circle-drawing-remix-with-small-impro?from=search#profileId-62315)

Important:

• The compass may initially have a lot of friction (especially for matte filaments). With more use, friction decreases a tad. Ironing can be enabled for top surfaces, which helps to eliminate friction. I added a little bit of lubrication fluid I had laying around from Hub Hobby to the flange of the top and the peg slots before assembly, which helped a great deal.
• This is a delicate tool. Pushing down on the shutters may skew them out of position. If this happens fully open and close the compass and they should pop back into place. You may need to fiddle with it a bit or remove the top to realign the shutters.
• If the compass is dropped it may fall apart, but it can be easily reassembled.

Assembly:

• After the build plate is completely cool, carefully use a scraper to work around the edges and remove the thin parts from the build plate (Parts may permanently bend if remove while warm).
• Place the Base on a flat surface.
• Hook one Shutter at a time over an outer peg of the Base. Work in a clockwise manner. When installing the last 4-5 Shutters, you will need to slide them under the first few initial Shutters while holding them in place and hook them over the pegs.
• Run your finger around the inner edge of the Base to align all of the Shutters in their open position.
• Rotate the Base assembly so that the slot on the edge faces you.
• Take the Top and lay it on top of the Base assembly so that the protruding nub is in the left edge of the Base slot.
• Shift the Top so that all of the Shutter pins are aligned with the Top slots.
• Push down on one edge of the Top with one finger and slide another finger around the edge of the top until it is attached to the Base.