Open segment bowl started - Petal

Bob Beaupre

Bob Beaupre

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Open segment bowl 48 segments 23 rows the top three are solid segmented rings the two outside are walnut with a thin layer of maple between them. Should be 1057 pieces.
Well I've designed it in WTP, also approximated it in Segment Pro to get the 3d view and the paint page. Picked up my wood Sunday and milled all the material for the open segment part. So we are off and running.
WTP screen shot
Pedal.png
This is the approximation view from Segment Pro
7.jpg 8.jpg

The paint page form Segment Pro
Pedal layout.png
now I have hand written the rows along the right side and the segment count across the bottom, trying to keep the right order for the colors.

I'm using six different species so I had to do some hand calculations and add a columns on the summary from WTP, as it only handles a max. of five species per bowl. I also have to summary fom Segment Pro but the profile is a little different then the one I did in WTP so I'm only have that as a reference.
Woods used are Maple, Walnut, Cherry, Padauk, Yellowheart, Wenge.

I have the segments cut for the first three rows, I've made then the same diameter so I have some less setup time.
Tonight I got the first row glued on and we will wait until tomorrow to sand it flat.
IMG_20161115_213200664_HDR.jpg
 
Segment edge length was 0.22". I'll have that for the first three rows. Pipe cleaners just fit, and they were pretty tight. I also use a dental pick.
 
Nice project. Pretty small pieces.

I have watched some of the expert bowl turners in our club doing open segment bowls. Quite a bit of time with pipe cleaners and dental picks. At times they had segments come loose when flatten the ring for the next row, or when they did some preliminary shaping. They stated keeping the tools very sharp helps.
 
Another great follow along. At some point turn your photos and text into a book to go along with the finished piece. It will definitely increase the joy of whoever purchases it and might just increase the price.
 
mfisher said:
Nice project. Pretty small pieces.

I have watched some of the expert bowl turners in our club doing open segment bowls. Quite a bit of time with pipe cleaners and dental picks. At times they had segments come loose when flatten the ring for the next row, or when they did some preliminary shaping. They stated keeping the tools very sharp helps.
Click to expand...

Yup lost three pieces this morning flattening the fist ring they are on and drying now
 
Just the sanding board. However, round the side edges of the board other wise the edge could catch a segment and send it flying. Don't ask how I know. :eek:
 
Bob Beaupre said:
Just the sanding board. However, round the side edges of the board other wise the edge could catch a segment and send it flying. Don't ask how I know. :eek:
Click to expand...

ooh, ooh, I know, I know. :oops:

I have made only one open segment bowl. It was given away as a gift. Had a lot of starts and stops , making and adding segments that flew away. Your pattern is much more complex than the one I did.

Thank you for sharing your photos of work in progress. I find it very informative.
 
Bob, I don't do open segment so it might not make any difference but why do the segments appear to be different lengths and the outside edges not matching?
 
The length varies a little because of the width of my boards, I left them what ever width they were, giving me a little more in wall thickness is some areas.
The outside varying is a function of the Seg-easy open segment plate. I talked with Jerry Bennett in Boston and there is some very small variations due to tolerance even with CNC machine when you get down that small, and of course there are some variations in the width of my cut segments. That's way for the first two rows I use my index fixture if you go back to the earlier picture you can see the first two rows are very consistent. Working with the Seg-easy plate I'll move segment from one slot to another trying to get the best match, but with as many different wood species as I have it is limiting. I did add some wall thickness to hopefully compensate for this. Even if all my segments were exactly the same there would be some variation in the OD / ID of the rings just because of the tolerances in the Seg-Easy plate. But he rings where you need them ie at the wall thickness are round and the gap is very consistant.

Hope that answers your question
 
Stuart here are the highs and lows on my 48 open segment plate, using the same segment in different locationsIMG_20161117_094044967_HDR.jpg IMG_20161117_094433804.jpg IMG_20161117_094724523_HDR.jpg

So if my segments are all perfectly the same there is up to a 1/8" variance on a side, not diameter

Now look at the spreadsheet a on a 48 segment ring 1/16" diameter change is 0.0041" in edge length
But look at the 24 segment ring a 1/16" diameter change is 0.00825" in edge length, double
So the accuracy has to be twice as good on a 48 verse a 24
calc.png
 
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