How to draw really large circles for circle skirts

I have a drafting compass from my art school days which comes in handy for circles…up to about a 10″ radius.

What is one to do when one wants to draft a circle skirt pattern requiring a MUCH larger radius? I mean, a drafting compass that can draw circles big enough for maxi or even midi skirts would be ridiculous.

Yeah, you can use the old “pin + string + pencil” trick. But you know what’s a lot cooler than that?

A yard stick compass set.

I forgot I found this and  forgot I bought it. I used it for the first time yesterday and was so floored! What a clever little contraption! Draw circles with a radius as long as the ruler you have. And because it’s a ruler, the measurement is built right in. (Plus, it’s made in the USA.)

How does it work?

It comes with 2 posts: one with an anchor pin, and one with lead.

Each post has a removeable knob and about a 1/4″ groove in which you can slot your ruler. (My wooden one was too thick.)

You unscrew the knobs, slide your ruler in, line the posts up to your desired measurements, and tighten the knobs until the posts are snug. My metal ruler is quite a bit thinner than the grooves in the posts, but the posts still stayed in place when the knobs were tightened down.

And voila: behold the mega-compass!

Bring on the circle skirts!