After I published my last project I got a request to make a circle helper for making targets on A4 pages. That's why I have on one side holes for 1" 3" 5" 7" diameter circles. But then I thought why not to expand it to make a bit more use of it.

There is a center line so you can make circle graphs.

The other side has holes after every cm.

There are small circles on the rim every 5 degrees.

The holes are 4mm diameter so you can use markers, but normal pens and pencils are fine too.

You can use it on a white board, might be good in the classroom also. You can make graphs or teach kids about electron shells or something like that.

NOTE: use some kind of oil in-between the two parts (I used vegetable oil from the kitchen), you can take it apart oil it and put the two parts together. I printed with PLA.

Elephants foot can be a problem, I recommend using a raft.

Check this:

Update added 03.09.22

• Indicators every 5 degrees

V1.1 available

Update added 04.09.22

• Magnet holes added on the corners 6 mm diameter 2 mm height

V 1.2 available