Rolimin

The Rolimin is a special ruler I bought about a decade ago.
Mine is much used and broken a couple of times.

If you have a source where to buy these, exactly these 13x7 cm with the circle templates, tell me about it! I want a replacement.
Update: I found one - multiplle actually - some time ago. And I switched to CAD (even at my age! Imagine that) for most things, since I make most parts with CNC now, so CAD and CAM have become mandatory. There are other roller-rulers available commercially in Germany, but they all are larger. I want a small one again – one that is not broken :-)

Like all roller-rulers, the Rolimin makes drawing parallel lines a snap.
The brass rollers only rotate at he same speed, so the movement of the ruler is restricted to parallel moves.

But the Rolimin also has a feature for drawing circles.
Small circles (1 to 10 mm diameter) are included as templates.
Larger circles can be drawn as well: pressing the brass knob at the top lowers a pin to the paper. With the pencil in one of the squares right and left of the brass knob, the Rolimin effectively becomes a compass.

When I was still making free-hand sketches on a daily basis, I simply loved this cute and very effective tool.

I still use it for quick sketches sometimes, since pencil-Rolimin-paper is soo much faster than Windows-Illustrator-Deskjet :-)