trying to understand all this segmented stuff

[Bob Hampton]

ok so i been a lurker for awhile ..make a comment or 2 once in a while ..now im on the row for questions
Im trying to get a grasp on all this segmented stuff and i think i have most of it down but one thing
When making the rings ..is each ring graduated ...in other words are the rings different size as far as length to get the step down for shape or are they all the same size and u shape it on the lathe?

I have been reading and reading and i see wide rings like about 1 1/2 and then some only 1 inch so whats the trick here?
questions and more questions ..guess i need a good step by step for old farts that need it simple...lol

thanks for any info
Bob

[Thom Sturgill]

From what I've seen, and like you I'm trying to get a handle on it, they are of differing sizes both diameter and thickness as measured radially as well as thickness measured vertically. Segmented work is much more 'designed' than non-segmented. Many turners do not decide on a final shape until they have roughed out a piece and see what the wood tells them. Segmented turners have to plan everything in advance.

Lay out your design on grid paper and then draw stepped blocks that not only contain the design curves and thickness, but give you some room to play. It helps to make the 'width' of the piece some relatively standard size to minimize the number of jigs and clamping rigs needed. There is PC software available that will aid in the layout.

[Bob Tate]

The software is nice but I don't use it very often. If you hunt, you will find a table that tells you what size segments for a given diameter ring. I mostly use that. If you set your lowest (first ring) then add 1/4" to each succeeding ring you get a nice taper. Or stack the same size rings together for a layer or two to get a more straight sided affair. It is fun to experiment. Mostly my segmented turnings com out the way they come out. I do not do a lot of planning. I know some people do and turn out some beautiful stuff. I do segmented turning to save wood. You would think Colorado would be good for lots of wood, and is if you want to turn Pine of Aspen. Not for me.
If you don't find the segment table let me know and I will post it. I do not believe it was copyrighted.
Bob

[Bob Hampton]

thanks guys for the help
I put all the idea's into the "think about it" top drawer while i puzzle on it a bit more...lol

[Robert McGowen]

For reference, I believe that most people use the terms width and length as pictured below.

Think of it this way, if all of the sides were straight up and down, then all of the segments could be the same width, because there would be no slope. Also, if they all had the SAME slope, the segments could be all the same width.

Once you add any variation to the slope of the vase, then the rings that have more slope than the ring that they are touching, needs to have wider segments. This is because the wall of the vase is no longer going straight through the segment and continuing straight through another segment, but is now going through the segment and turning or changing slope within the next segment, so that next segment has to have more wood (width) to it.

In the picture of the vase, the wall of the vessel is drawn in colored lines. You can see that layer 3 can have segments that are not very wide compared to the layer above and below it. That is because layer 3 does not have much slope, but the layer above and below it have a lot of slope compared to layer 3, and therefore, need much wider segments.

Clear as mud? :rolleyes:

[Brodie Brickey]

Check out Seggy's Dream a video by Malcolm Tibbetts

http://www.youtube.com/watch?v=fRn_mzDYq-s

Although the video tells a story, it also shows the process of segmenting a vase.

Malcolm also has a book and instructional videos on segmentation. I've only used the book but it is clearly written and illustrated.

Different heights and sizes on a segment will create a different look. If you want something to stand out more, you can use sizing to emphasize.

Here are some examples from his site:
http://www.tahoeturner.com/gallery/91.html

http://www.tahoeturner.com/gallery/86.html

http://www.tahoeturner.com/gallery/78.html

http://www.tahoeturner.com/gallery/66.html

[Larry Marley]

Hi Bob,
here is a cross section of a simple bowl.
As Robert as stated:
You will see when the sides are vertical the segment width is narrow and as the slope of the wall approaches horizontal the segments increase in width.
Malcolm Tibbetts has a very good book on this.
you can also check out Kevin's woodturnings. he has a tutorial on how to design a bowl.
http://www.turnedwood.com/

Larry

[Bob Hampton]

ok now this thing is beginning to make a little sense for a change
so what u guys are saying then is that each ring is wider then the previous ?
but are still the same amount of segments just that each ring segment is a little longer and wider as u progress up correct or am i still in the dumb chair?

So far from what i have been reading (and Mr Tibbets has a great site) if u start out lets say a 12 segmented ring with the base segment length starting at 11/4x3/4 thick then the next ring would be increased in length by an 1/8 inch and width by 1/2 inch? or am i still lost ...this is the confusing part to me ..i know its simple but i guess i still havent grasped this yet ..when i do i will feel soooooo stupid!...lol
ahhh well i just need a good challenge to keep from going stirr crazy not being able to work right now.
appreciate all you guys and your patients with me
bob

[Bob Tate]

You pretty well have the idea. I think if you do one you will fall right into it. Most of the time I keep the width the same and just make segments longer or shorter. Either way works, and will impact shape.
Bob

[Richard Madison]

Some good explanations there. And/but if you are serious about trying segmenting, just buy Malcolm's book The Art of Segmented Woodturning, available from Amazon or himself at his website (which you already know about). Still use it as reference for compound stave angles. Am not a fan of software, and always just draw a half section view on engineering paper (with 1/4" squares) and scale the segment widths and lengths (based on O.D.) from the drawing.

[Bob Hampton]

guys i would really like to thank all u for the time u took to help me out here with all this segmenting stuff!..lol
After a lot of reading here and on the net and playing around with scrap wood (thankful for the pile i have) and some very good advice from here ...I think i FINALLY have a grasp on it ...not firm mind u but a hold of some sort..im going to try my first bowl today and see where it goes.

I agree its going to be alot of trial and error and a great deal of patients ..
I did manage to find some good calculating charts that show length and width of each segment per ring so think i have that down finally ..that seems to be where i was having a problem trying to understand was how to get the measurements for the size of each ring and also how much to increase the size per segment in each ring to make it step up or down to make the shape.

So off to the shop and boggle the rest of whats left of my tired brain cells..lol this should be a good challenge anyway.
Thanks again for all the help
Bob

[Gerold Griffin]

Certainly alot of good advice given to you here. If you haven't already check out Malcolms book the Art of Segmented Woodturning. That is my go to book for segmenting. Also if your like me I flat hate spending the time drawing out each ring. You may want to check out http://www.woodturnerpro.com/
It is a whole lot faster way get your design on paper and into the shop! Not sure if they still do it or not but they used to let you try it out free for 30 days.

[John King]

Bob - Checkout the subject table at http://www.woodturner.org/products/aw/more_info/spring_2006/SegmentEdgeEstimationTable.pdf. If you know ring size and number of segments, you can get segment length from this table. - John

[Dick Sowa]

Most of the confusion with segmenting seems to come with the use of various terms for the segments. This is how I use the various terms, so I won't confuse myself, although confusion is getting easier with age :)

Segment LENGTH is the distance across the longest flat side of the trapezoidal segments...which also is the outside. The length x number of segments approximates the outside circumference of the ring.

Segment WIDTH refers to the width of the board from which the segments are cut. So a wider board will give a wider segment, which will result in a ring with a thicker wall...or more material to remove when turning to final wall thickness.

Segment HEIGHT refers to the vertical thickness of the segment, which is equal to the ring thickness. The height of one segment x the number of rings equals the height of the vessel or bowl.

[Bob Hampton]

john thanks for the link ...ill go look at that

Dick..thanks that helps to understand more...thats how I have been looking at it also ...whole lotta stuff to take in and yes it gets confusing when the mind has aged..lol
thanks again
Bob