How to make segments

[Bob Strand]

Would like info on angles, length how to cut segments. Making a bowl out of a piece of 2"x6" square rosewood and want a segmented bottom and top out of maple flooring.

 

[Gary Beasley]

Look at youtube for some very excellent videos covering those aspects. Earl Rasmussen has some good ones.
You will likely need to put together a cutting sled or learn the setup for a chopsaw done safely. Some folks even manage it on a bandsaw.

 

[Bob Strand]

Thanks Gary. I did some Utube and its full of good stuff but I was looking for some reading material that would give formulas for how to measure and create original works. The sleds shown appear the way to go for precise cuts. Thanks again.

 

[Gary Beasley]

One book I have is Woodturning with Ray Allen by Dale Nish. It goes into quite a bit of detail on techniques and equipment.

 

[Kim Rymer]

Hi Bob:

AAW Explore! has 95 articles about segmenting (projects, gluing, design, cutting, etc.)

Steps

• Go to the AAW website at woodturner.org.
• Log in with your username and password. (If you don’t know your username and password, call the AAW office at 877-595-9094.)
• From the main menu, hover your mouse over “Read” and click “AAW Explore!”
• The AAW Explore search page will be displayed.
• In the section labeled “Category” select “Segmenting” from the dropdown menu and click the “Search” button.
• A list of all the articles will be displayed. Scroll down the list, if one of the articles is of interest, simply click the world icon in the “Links” column to open the article in a new window.

I hope this helps.
Kim

 

[john lucas]

Don't waste your time on youtube. Get Malcolm Tibbets book on Segmented turning and learn from the master. Just about everything you want to know is in there. the art of segmented wood turning Other than that join the AAW and use Al's suggestion.

 

[Raul McCai]

Would like info on angles, length how to cut segments. Making a bowl out of a piece of 2"x6" square rosewood and want a segmented bottom and top out of maple flooring.

Malcom Tibbits has a book and a couple of great videos that he sells

 

[Bill Boehme]

Malcolm Tibbetts has several books. The one that you want is The Art of Segmented Woodturning.

 

[john lucas]

Thanks Bill. I meant to post a link to the book but got in a hurry and forgot.

 

[Bob Strand]

Thanks Raul. I'll keep the Tibbetts book in mind. I did go to the AAW segment site and dipped into that most informative reservoir. Wow. Thanks Kim.

 

[JeffSmith]

Just watched Malcomb’s latest youtube video on building a tower. Great explanation of the process both conceptually and the build. Hard to concieve of maintaining control over all aspects of such an involved and time consuming process. I’m in awe.

 

[John Torchick]

Kim, thanks for calling attention to the AAW Explore. I need to pay more attention to that resource.

 

[George Stratton]

If you are trying to figure the length of a segment without too much computer help and a simple pencil compass and simple plastic protractor, just draw a circle of the size you want, put a horizontal line through center, draw 15 degrees up and down from the horizontal, and draw a verticle line slightly outside the circle diameter. This would be for 12 segments. Measure the verticle line from one 15 degree to the other.to find the length you need. Simple way. Of coarse I draw it up with autocad at home and the computer figures it out for me. But hey, it works. Geo.

 

[Mike Johnson]

If you search on Google there are several pdf charts that list diameter and wedge degree for making various size and number of segment rings. This chart also gives you the inside lengths and outside lengths of each segment so you quickly determine if you have a workable design. As George mentioned above drawing a circle and dividing the pie into segments is the basic concept in designing segmented pieces. You then need to develop a drawing with the rings stacked on top of each other to determine your wall thickness and potential contours of the vessel. Alternating the segment alignments is the first basic design and from there it can get very complex if you have the time and patience to create something more challenging. Grain direction and color arrangement patterns can also add to the complexity of the project. You can get carried way going down this path if you have the time and patience, however the finished product can be a masterpiece if you can pull it off.

 

[Gary Beasley]

I found an app for my android called Segment Calculator by Byroid Apps that will give you specs after entering the inner and outer radius and the number of segments giving you cutting angle, segment length and segment width. Its not the only app out there either, look and see what makes you happy. Its really handy and quick.

 

[Richard Andrews]

As far as cutting segments, the easiest and most accurate method I have found is the “Wedgie Sled” on Jerry Bennett’s website http://segeasy.com/. He has some YouTube videos demonstrating the use of this table saw sled. FWIW, its use does not require the purchase of the “Wedgies” he sells, though they are very accurate. A 12 segment ring can be made using a simple 30 degree triangle. I have found that in the vast majority of cases, the ring will not have any gaps and not require sanding to adjust the ring. In my experience this sled is much easier to use and much more accurate than using my miter saw.

 

[Mike Johnson]

There are various methods for cutting accurate segments, the table saw sled is one way which many use along with the Wedgie variation.
A compound miter saw can work very well with a stop set up for accurately controlling the length of each segment being cut.
Several companies make precise table saw miter gauges that can accurately set the cutting angle and duplicate it each time.
Once you have a good system set up you can quickly cut a lot of segments.

 

[john lucas]

Ditto on the Wedgie sled. I have used all of the methods and find it the easiest. This is from a guy who does not do a lot of segmented work so each vessel is kind of a new trial not totally dissimilar to a new turner. Over the years I've moved, purchased new equipment and other variences that must be taken into account. So I almost always end up doing cutting some scrap to make sure the new system works. With the Wedgie sled the trial and error is almost non existent.

 

[Mike Johnson]

All three methods will work equally well if the angle of the blade is perfectly aligned. If you are using a table saw to cut traditional shaped segment pieces and your vertical alignment of the blade is off by any amount you will have issues. Using a scrap piece of wood and cutting a ring of segments will let you know if your blade alignment is accurate. Any misalignment will show up as a small gap between several of your segments in the ring. The Wedgie templates when used will guarantee the angle on both sides of your segments. The other methods mentioned will also produce accurate angles for both sides of the segment if your stops and angles are set correctly. A well built table saw sled with a properly designed angle miter will produce accurate pieces if the sled runs true and the miter fence is set properly. I have an Incra miter fence which works quite well if you properly set the tool up to work with your brand of table saw. A quick way to check a ring of segments is to cut a set and stretch a rubber band around the circumference of the ring holding the segment ring together, hold the ring up to a light source and check for gaps with the light shining through any voids. If your system is set up correctly most of your rings will be a matched set with maybe a little touch up required with sand paper to clean up any tear out on the cut edges.

 

[Doug Rasmussen]

What about information about matching wood characteristics for segments? I would think things like wood density, relative changes with humidity and so on should be considered.

 

[Mike Johnson]

Moisture content and wood types are most definitely a consideration in segmented work. Segment size, glue type and wood finish types are also considerations that should be made. Some people have encountered raised glue joints from expansion and contraction of the finished segmented piece after it is exposed to changes in the environment that the piece is exposed to.

 

[John King]

What about information about matching wood characteristics for segments? I would think things like wood density, relative changes with humidity and so on should be considered.

Theoretically, it's a concern. Practically speaking, I have not found it to be a problem. I select woods for color, contrast, etc. without regard for density. Have never had a segmented bowl come apart at the joints because of defferential movement of the segments. Some bowls that I have kept are 12 years old. Never had one returned by a customer. - John

 

[john lucas]

Ideally yes. Woodmovement especially if it's dramatic or if the grain doesn't run correctly will definitely cause a problem. I have a large piece upstairs that had a cocobolo rim. I suspected one, that it might be hard to glue the Cocobolo, and 2 because the grain didn't run the same way as the rest of the vessel (which was a bowl from a board) I thought there could be a problem. So I kept it and didn't give it away or sell it. sure enough about 6 years later the rim started to seperate from the rest of the vessel. Just a little bit. Still very nice piece but I would not want a customer of friend to have a piece with a crack. You can find specs on woodmovement of all woods online. I'f I'm working with a wood I don't know I look it up. If the movement is radically different than the other species I'm using I try to change. Since I don't do a lot of segmented work I want to give myself the best chance of success I can. Early on I did a lot because I didn't know you could use green wood or dry wood yourself so everything was glued up. Back then I also had lousy tools so I"ve had to go through all the various processes to improve my techniques.

 

[Doug Rasmussen]

The few larger segmented pieces I've actually handled in galleries all had at least a very slight feel of the glue lines. They weren't visually noticeable enough to be a problem IMO.

Last weekend I talked with Martha Collins at a Seattle craft fair, She had a number of bracelets like the attached image (from the AAW site), no feel at all of the glue lines. She had one bracelet she said had movement from the heat of bright spot lights in her booth. She was taking that one back to the shop to sand and re-lacquer. I wondered if at some point the wood movement ever stops.

 

[john lucas]

Wood movement never stops but when you have really small segments individually they don't move as much. I had plannned a test but haven't had time to do it. I want to make 2 rings. One with 12 segments and one with 36. Measure them in 2 directions throughout the year and see if one moves more or differently than the other. I think I got away with a lot of glue ups that should have broken when I first started because they were all 6" or less in diameter. You have less movement in a 6 inch bowl than a 14" bowl. The cocobolo bowl I mentioned above is almost 18".

 

[Ely Walton]

If you have one (or have access), I use a very solid chopsaw with a 14 inch Forrest blade. Leave the same setting, use a stop block, and flip the board after each cut. Angles are spot-on even with a large number of segments. the challenge for me is flattening the rings before vertical (bottom-to-top) glue-up. If less than 15 inches they go into the planer - no problems, but I have to glue up larger rings both horizontally (segment-to-segment) and vertically at the same time to avoid gaps. I have seen some methods where a large ring is mounted on the lathe and sanded using a long board for a sandpaper backer -- but just would not like all that dust... Regardless, segmented turning prep is very time-consuming. I would rather mount a big, green blank and just start making shavings!

 

[Bob Strand]

Wow, again. The knowledge you guys possess and your willingness to share it is, to say the least, commendable. I ended up going with the mitre saw and measured stop block, and after several re-adjustments and trial pieces, came up with the right angle. I need to segmented tops for these shallow rosewood bowls I'm making but I don't do much segmented work anymore but the info is totally appreciated. Thank you all.

 

[Bob Strand]

If you have one (or have access), I use a very solid chopsaw with a 14 inch Forrest blade. Leave the same setting, use a stop block, and flip the board after each cut. Angles are spot-on even with a large number of segments. the challenge for me is flattening the rings before vertical (bottom-to-top) glue-up. If less than 15 inches they go into the planer - no problems, but I have to glue up larger rings both horizontally (segment-to-segment) and vertically at the same time to avoid gaps. I have seen some methods where a large ring is mounted on the lathe and sanded using a long board for a sandpaper backer -- but just would not like all that dust... Regardless, segmented turning prep is very time-consuming. I would rather mount a big, green blank and just start making shavings!

I'm totally with you Ely. All this angle measuring and variances make my un-geometric mind hurt. Good info that it is but, like you, I enjoy a piec of wood that comes off the lathe and gives me a warm, satisfied feeling.

 

[Mike Johnson]

This is a link to one of the pdf files that provides help for cutting rings.

http://www.spacecoastwoodturners.com/newsletter/Segmented_Turning_Table.pdf

 

[Gary Beasley]

Earl just put out another video redoing his sled

View: https://youtu.be/1OspCgUk4Hg

 

[Bryan Lisowski]

I know this thread has been inactive for a few months, but figure it is the best place for my questions. I would like to build the sled Jerry Bennett designed. Building the sled is straightforward. On his site he sells the wedges, but I would prefer to make my own. Either I'm having a brain cramp or have been out of geometry classes to long. Does anyone have a template they have used for different amount of segments? Second question, how accurate is the miter set/segment deal?

 

[Pavle Ancevski]

Just divide 360 with the number of segments.
For 18 segments the wedge should be 20 degrees, for 8 segments = 45 degrees
Be sure when you set the wedge in the sled to have it centered, or the trapezoids you gonna cut will have different left and right sides. Some like that, but usually people want trapezoid with parallel top and bottom, and same right and left side.
I am not using wedges. I have bought a digital protractor, and I am setting each fence of the jig to be on exact angle with the line of cut of the sawblade. That made me segments that I do not have to glue in half. Just get them all with a hose clap and they are perfectly fitting.
Just remember, for 8 segments the angle is 45 degrees, but you are setting each fence to be at 22.5 degrees (half of 45) with the blade cutting line.

Take care

 

[Stefano Bastianelli]

This is what I did for the wedges. On the CAD or any design/drawing software just draw the angle you need. You can also google the angle like "22.5 degree angle" set the search to images. Print, stick to a foamed cardboard, cut them with a knife and a ruler. You can also make them from HDPE boards easily if you can rely on a precise miter gauge.
If you are careful and precise with the cuts, they can be accurate as much as those cut on a cnc. I use them and I don't even need to glue half rings.

 

[Pavle Ancevski]

Also, I like these two calculators for segmented work:
https://www.blocklayer.com/woodturning-segments.aspx
https://marleyturned.com/Shop_Utilities.html

They give you all the dimensions for your cuts including the angles on each segment.