Review on General Tools 523 Adjustable Trammels by Chad Boho

The only limit to the size of the circle you can create is the length of the bar you provide. Only criticism is that the tip is smaller than a pencil. I usually use it with a pencil and point. I remove the nut holding the tip, being careful not to remove the cap and spring underneath, and then stick the wooden pencil firmly in its place. It may be better to grind the pencil to make it fit better. When I change a nut, I flip it so more thread is tighter. Beam sizes may vary. I use 3/4” x (3/4” - 1 1/2”) x whatever length you need. A 26 inch beam creates a 4 foot diameter circle.