I wanted to explore wood turning and make a huge vase. To figure out how it works and avoid all the usual pit falls, I wanted to make a small scale vase first. Little did I know that what I made as a prototype would be the one i will eventually display in the show at university. So this little vase was done with only intentions to learn and experiment, with no thought on how it will look or fright that it might fail.
The first step on making this was the design. I will illustrate multiple steps I went trough, and how and why I did them.
I took student membership at Techshop (www.techshop.ws), so I can use the facilities. I took a SBU for wood lathe and went to work. I got some personal tools for advanced hollowing.
Step 1: design
I decided on segmented vase as no more one is limited to the size of the wood one can find. I wont mention the disadvantages, but there are lots of advantages, like having no end grain to bother with, using all the scrap wood, etc, etc.
Segmented vase is made by putting together pieces of wood, to make a rings, stack the rings, and then turn them on the lathe. Hollowing becomes easier, but the design is constrained after you start.
The design is first created as a half section. This is the shape of the vase or bowl you have in mind. I roughly used the thickness and the width, I will need to have sufficient overlap between layers. I decided to make each rings with 12 segments (each segment is a regular trapezium, with an included angle of 30 degrees). I tested my math skills, and just to be sure, by cutting some foam core and putting them into a ring.
I made the a CAD file (this can be done on paper with a ruler and pen too) and took a 1:1 print of the segments i have to cut and number of segments i have to cut.