Lizzardhead, this one’s for you!!
Dave once asked me if I could make a 3 sided obelisk. I have been thinking about it and I cut a scrap of spalted beech cut to a triangular shape and set it under the bench while I thought about how to hold it. I came up with this method to safely cut the triangular piece to the center point. I made an L shaped support from scraps and then fastened the bottom of the triangle to it with 2 screws.
I first marked off the center of the triangle on the top and the bottom of the piece. Then I drew a line from the bottom corner of the first side to cut to the center of the top.
I mounted the triangle to the L block with one screw and spotted the second hole location when the side to cut was truly vertical.
Then I cut it on the band saw from the center of the top to the bottom outer edge.
I repeated that process for the the other two sides to draw the line to the top center from the base and had to use a piece of scrap under the part to support it during the cut. I cut though it in the process, but that’s okay.
The last cut was the tricky part because the center is no longer at the top of the piece because I cut that away. So I used a square to transfer the center from the bottom to the top and mark it and draw a line to the base for the last cut.
I found that you lose about 30% of the length in this last cut so you have to plan for that for your final height of the piece. On a 4 sided obelisk, the start height is the final height.
This was not a project but a just a test to see how it worked and it cut very easily and safely in this way.
Here is the final obelisk with 2 coats of Clear Matte spray:
-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!!