Segment length and angle determination

hey everybody uh so we've already done one or a couple of videos on segmented bowls uh but in today's video we're just gonna break down how to figure out how long of a segment you need and the angle at which you need to cut it so first i want to talk about the length the segment edge length and the edge length is going to be the long end of the of the segment so to figure that out you need to first know your radius so half of the diameter the width of your bowl so once you have that number you are going to figure out the circumference of the bowl and to figure out the circumference we've got 2 times pi times the radius and we're going to divide that number by the number of segments that you're going to use in your bowl for example if i were to use a 20 segment piece or a 20 segment ring and my diameter is uh 12 inches so the radius is 6. so we're going to have 2 times pi times 6. and that number two times three point one four times six equals 37.68 and we are going to divide that by 20. gives you 1.884 inches so approximately 1 in seven eighths so the second edge length is going to be one and seven eighth inches and that's your segment length and you're going to do that for every uh every ring that you that you're making now let's talk about how to figure out the miter angle of your cut a circle is 360 degrees and so you're going to divide that by two times the number of segments so again let's use the 20 segment the 20 segment example so you have 360 divided by 20 times 2 so 40 and that's going to give you 9 degrees very similar to a a square or a rectangle with 90 degrees again a square or rectangle is still 360 degrees time or divide that divide 360 by 8 and you come up with 45 degrees and that's it's that simple so if i wanted to do say a 10 segment ring i would do 360 divided by 20. that's going to give you 18 degrees 8 segments 22 and a half degrees now most miter fences for your table saw have a built-in stop at 22.5 degrees if you are making a ring the fewer number of segments that you have you just have to make that make sure that your ring width is uh is a little bit wider because you're going to have significantly longer edges and the more segments that you have the the shorter your your edge length is going to be and so the more round of a circle you're going to have right out of the gate so that's it it's it is uh relatively simple uh and if you uh if you have access to it uh there are many many uh free apps that you can use one website that i've used in the past is a block layer they have a segmented ring calculator in the in the app itself or in the uh the website itself woodturner pro is the program that i use most often where i can open up and see the design as it comes to life and yeah tom do you have any questions did i leave anything out no i just wanted to go back and put emphasis on this part that i didn't think we emphasized enough in the original video i appreciate you taking the time to do that well it's not a problem anyway i'll uh i'll list the links to the reference items that you mentioned and and we'll go from there so thanks for watching thank you thanks guys

Channel: The Southern Woodworker

Views: 12,193

Keywords: Segmented bowls, woodturning

Id: spz8sXExoJc

Length: 5min 49sec (349 seconds)

Published: Sun Aug 23 2020