In my project, Cyclone, a comment from Bearpie with a request to know how to find the size of an angle of any segmented project. Here I am answering his request as a blog to be available for anyone wishs to benefit of it.
IF you are interested in finding it mathematically, here is an algebraical law:
The Required Angle= [(360 devided by sides number) – 180] devided by 2
The required angle for 12 sided= [(360 devided by12)- 180] devided by 2 = (30 – 180) devided by 2 =150 devided by 2 = 75 degrees (The answer)
IF you dont like that, follow this:
The required angle for 6 sided ring is 60 degrees, 8 sided ring is 67.5 degrees ( common ), 10 sided ring is 72 degrees 12 sided ring is 75 degrees (very common), 18 sided ring is 80 degrees, 24 sided ring is 82.5 degrees ( good for open segmented ), 36 sided ring is 85 degrees ( good for open segmented as well) and 48 sided ring is 86.25 degrees ( good for fine design) and so on….
REMEMBER, the angle alone is not enough for perfect tight ring. It needs another two factors, A- all segments must be precisely the same length. B- Cutting must be precisely vertical or 90 degrees.
So, if you insure precise angle, precise length and precise verticallity, you will do a good job.
TO INSURE precise angle: It is not enough to set your miter on a requered angle. You have to test it with a sacrificial piece of timber (we have many of them), probably 2 or 3 times. Every time, ajust your miter accordingly by move it to left or right.
TO INSURE precise same length of all segments, you have to have a LENGTH STOPER on your miter. This stoper has to be ajustable, because you need to ajust it for each level of your project.
TO INSURE vertical cut, I recommend using good electric miter cross cutter.
NOW, How to find out the segment length of each level, needs some drawings which I am preparing but they are not ready. So, I will come back to you in few days time. Thank you all.
-- Sam Shakouri / CREATING WONDERS WITH WOOD.....Sydney,Australia....