Did you know that you can cut circles on a band saw by simply driving a nail into a piece of plywood clamped to the table, using the nail as a pivot point for your
workpiece?
Well.. you can!
I used an old shelf and some scrap ¾-in. plywood to make my jig. It is essentially an extension table that allows me to install a finish nail [pin] in the top.
The only limitation to the size circle you can cut is the length of your fence. Larger circles require larger aux fences.
To make my jig:
The first order of business was to “send” the jig through the blade to create the saw kerf, then shut off the saw when the extension table reached the edge of the bandsaw table.
The old shelf I was using as a fence, had a 1×2 edge nosing applied, and I used that nosing as a stop, indexed against the edge of the band saw table.
I installed 3 scrap pieces of plywood underneath the fence, and against the sides of the band saw table as stops, and fence stability supports.
The supports function to index the table with the blade but also to hold everything steady while you turn the actual circle stock through the blade.
I then level the table and attach an auxiliary plywood leg to the support table to keep it from sagging under the circle stock weight. Two screws hold this leg in place.
I marked a straight line from the blade down the extension table. Measuring out from the blade, and along my line, I measured and marked the column bases radius.
A 6 penny finish nail is then installed on that radius point.
NOTE: To figure out the radius measure distance from the center of a circle to any point on the boundary is called the radius. The radius is half of the diameter.
I needed a 14” column base so I glued and clamped up two 2x8 PT blocks the night before.
Assuming my wood piece is a square, I draw two intersecting, diagonal lines from the corners to determine the center. Once the center is marked, I drill an 1/8-in. hole through the center.
I then place the soon to be, circle stock over the extension table 6d nail, turn on the saw and slowly turn the wood clockwise though the blade, cutting my circular column nases.
After all, 3 bases were cut I ran them through my router table to round them over. A quick sand and they were ready to go.
NOTE-
Thinner blades work best with the circle cutting band saw jig in fact a ¼-in. blade is perfect.
Avoiding the center hole on your stock:
Some projects like furniture and tabletop pieces require you to cut precise circular shapes while avoiding the center hole in the stock.
To do this on the circle cutting band saw jig you need to use two-sided tape and attach your stock to a sacrificial surface which is mounted on the 6d nail, …
or drill your hole on the bottom of your wood, but not all the way through.
#workshoptip #Bandsawjig
#woodworking # CuttingCircles
6 сен 2024
