A Trammel Set is a clip on compass for drawing circles. This Set manufactured by M Power is a "Flat lying" set for drawing and cutting circles. Simply clip the set onto your metal rule to lay out any size circle. We tried it on a 4' long 2" rule, and a 12" long 1" rule. In both cases it drew a perfect circle accurately and with ease. The accuracy depends on your patience and care when tightening down the pinch bolt. This set will also let you mark a parallel line with one of the trammel heads and a try square as shown in figure 2. another use of this set is drawing duel parallel lines on your work using an engineers square as shown in figure 3.
The set also lets you cut circles in veneer. A small blade holder replaces the pencil in the trammel head. Rotating the cutter 3 or 4 times should complete your cut through a typically thin veneer.
Overall this set is well constructed and easy to use, two things I like in a tool. I found that using this marking set in conjunction with the circle cutting jig I use on my band saw made marking and cutting both accurate and easy to do and a perfect addition to your tool box. Making this September's Cool Tool. Selling online for about $22 won't put a dent in your tool budget. Check out all the features of this set on the M Power website.