- MAKE A TRAMMEL -
For this project I used a 1 inch by 3 inch scrap of pine I had. At my router table I created a ten inch long slot by making a series of cuts with a 1/4 inch straight bit, raising my bit in between each cut until I was all of the way through. At ten inches this will give me a radius of twenty inches, which will be more than sufficient for my needs. But you can make this slot as big or as small as your needs require, just remember this slot is half of the overall size of this trammel. So if you choose a five inch slot your trammel will create a ten inch diameter circle. |
The adjustment for the trammel I made from the cut off that was created at the band saw. This piece requires 3 holes to be drilled with a 1/4 of an inch drill bit. The first hole will be to except the pencil and is drilled all of the way through from end to end. The second hole is for a retainer bolt and is drilled all of the way through the side about 1/2 of an inch from the first hole drilled. The third hole is for an alignment dowel and is drilled directly in line with the second hole but is 1/2 of an inch to the opposite side of the first hole. Note, this hole does not go all of the way through it only goes in about a 1/4 of an inch.
This assembly can then be placed into the main body of the trammel lining up both the dowel and the carriage bolt with the slot.
Then a washer and a wing nut can be installed on to the carriage bolt.
Then a washer and a wing nut can be installed on to the carriage bolt.
To use the trammel just mark the center of your circle and place the pin of the trammel on your mark, then loosen the wing nut and adjust to desired diameter then tighten the wing nut and draw your circle.