Charlie Plesums
Member
- Messages
- 1,523
- Location
- Austin, Texas
If you are doing tapered rectangles, like the examples, beware that the miters at the corners are not exactly 45 degrees. In a tall column they may be close enough to 45 degrees to not matter, but you may need to jury rig your angle a little (I have never been successful at calculating the angles, but if the top is 1 inch in from the bottom, tilt your blade 45 degrees, raise the top 1 inch as it goes through the saw, and you are home free - both angles are cut at the same time.
If you want round columns such as the full or split columns that I made for these wine cellars - see www.plesums.com/wood/other/winecellar.html this is how I did them...
Using 4/4 stock, I made a cylinder of 12 segments (tilt the blade 15 degrees). To get the taper, I calculated that the top circumference is 6 inches less than the bottom circumference, so the top of each segment is 1/2 inch narrower than the bottom. Just before each cut, I moved the top 1/2 inch away from the rip fence. Flip the board before each cut, and there is practically no waste. Glue the column together with lots of hose clamps, turn, and live happily ever after.
Of course if your world isn't perfect, glue two sets of 6 segments together at a time, so that any error (gap) is in the unglued surface, then flatten on a jointer before gluing the two halves of the column together.
Since the column is hollow, I screw a piece of plywood to the top and bottom to mount it on the lathe. Be sure to drive a screw into each segment so things don't fly if a glue joint fails (or in my early columns, I left a hose clamp on the top and bottom during turning)
If you want round columns such as the full or split columns that I made for these wine cellars - see www.plesums.com/wood/other/winecellar.html this is how I did them...
Using 4/4 stock, I made a cylinder of 12 segments (tilt the blade 15 degrees). To get the taper, I calculated that the top circumference is 6 inches less than the bottom circumference, so the top of each segment is 1/2 inch narrower than the bottom. Just before each cut, I moved the top 1/2 inch away from the rip fence. Flip the board before each cut, and there is practically no waste. Glue the column together with lots of hose clamps, turn, and live happily ever after.
Of course if your world isn't perfect, glue two sets of 6 segments together at a time, so that any error (gap) is in the unglued surface, then flatten on a jointer before gluing the two halves of the column together.
Since the column is hollow, I screw a piece of plywood to the top and bottom to mount it on the lathe. Be sure to drive a screw into each segment so things don't fly if a glue joint fails (or in my early columns, I left a hose clamp on the top and bottom during turning)