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Calculation of Ring Sizes for Segmented Spheres--A Correction

Dennis J Gooding

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Despite numerous proof reads before posting this thread in the Tutorials and Tips Forum, I managed to define a parameter incorrectly. The parameter θ was incorrectly defined as θ =180/N, whereas it should have been defined as θ = 360/N. I have since corrected the error, but just in case someone is already trying to use the old result, beware. SFTI
 
Is is definitely off the subject but I’ve gotten intrigued by tumbling bowl projects. As a new turner I’ve watched a bunch of you tube videos but I guess I need detailed step by step instructions which I have have found hard to find. Do you know of any sources?

Thanks for your posts
 
Sorry Peter, but I have I have never done a tumbling bowl and did not even know what it was until looking it up just now I expect that others here will be able to help you however. DJG
 
I'm just starting to dip my toes into segmented turning. The turning part is easy. Cutting the wedges on a wedgy sled is easy. Gluing up the segments is not too hard either. Making the wedges the correct thickness and width so I don't run out of wood is the tricky part. I've got my first bowl drying up in the shop now. I learn something new every time I try it.
 
You might be interested in this site: https://cdelker.bitbucket.io/segbowl/

It lets you design the bowl's profile in 3D and then adjust the particulars (segments, rings, etc.) and print out the requirements/cut list.

Things you can adjust:
  • Drag and drop drawing of bowl profile
  • Set thickness and number of segments in each ring
  • Rings can contain segments of different arbitrary sizes
  • Color individual segments or patterns of segments in a ring
  • Generate a report of all dimensions and cut angles in fraction or decimal format
  • Change units between inches and millimeters
  • Rotate individual rings or "twist" for spiral effect
 
Thanks Mike. That's a great tool. I'll put it to use. I'm not really ready to spend a bunch of money on Segment Pro software...... yet. I just finished my 1st segmented bowl. I got the cut list from a Google search. It's 11 inches in diameter and has 97 pieces. Maple, walnut and purple heart.IMG_2447.JPG IMG_2448.JPG I think it turned out pretty well.
 
Thanks Mike. That's a great tool. I'll put it to use. I'm not really ready to spend a bunch of money on Segment Pro software...... yet. I just finished my 1st segmented bowl. I got the cut list from a Google search. It's 11 inches in diameter and has 97 pieces. Maple, walnut and purple heart. I think it turned out pretty well.

You're right! It's gorgeous. That's the best free, online resource I've discovered. I visited another site not to long ago that had a very good method based on some printable 1:1 graphs where you'd draw the side plane of your design and then use a spreadsheet to generate the necessary cut measurements. As usual, I couldn't find that link when I wanted to share.

But this new one is better. At least for me. I'm not likely to spend a lot of money on buy-me software when this app does what I need.
 
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