I can also use it to cut circles up to 60cm in diameter thanks to this part that will act as a rotation axis(first photo). After cutting all the plywood pieces to size, I’ll machine this part that will slide along this U-shaped slot in the band saw table. I’ll use this piece of HPL board, although any kind of hardwood will do as well(second photo)
We must be very precise when cutting the piece to ensure it will slide smoothly without too much slack. I make the final adjustments with a piece of sandpaper stuck to a board. Looks like it’s ready now. I’ll make a little slot in the sled to help me position and lock the HPL(fourth photo).
Now I’ll make this rebate that will help me achieve perfectly straight cuts(first photo). Since this disc is not high enough, I’ll make this series of cuts first. This slot will allow me to slide the part that acts as rotation axis to make circular cuts..
Now I’ll screw these two parts that make up the other part of the sled together. I mark and drill the position of the screws that will attach them to the sled. I’ve used this method of making a rebate which lets me attach it and detach it when I need to cut circles.
Now I make holes to lock the HPL in place. I use the same holes to mark the HPL itself. I drill it with a bit that is half a millimeter smaller than the diameter of the screws, and I thread the hole with a tap(fourth photo).
Now I prepare the part that adjusts the diameter of the circles. We could also use hardwood instead of HPL. I’ll use a shelf support pin I had lying around in the shop as axis. I drill its position and that of the screw, allowing me to lock the part at the desired diameter.
I finish machining it with the band saw and check if everything is correct. By tightening the screw, the part expands, but not too much, meaning we must be very precise to obtain a good lock. In the plans I used an aluminum “U” profile inserted in the table channel, but since I do not have it in the workshop I will not use it.
I’m going to test it. First I’ll try to make a tenon using the fence and the sled. Looks like it’s working well! Now I’ll try to cut a circular piece that is 200mm in diameter. I measure the radius with a measuring tape measuring from the band saw blade to the shelf support pin and tighten the screw of the part that acts as an axis.
The cut is smooth and everything seems to be working as intended. Of course, I can also tilt the band saw table and make circles with the edge at an angle. I’ve left a gap in the base of the band saw so that I can always keep the sled accessible. And that’s all for today. See you soon!