Stave Segment Techniques

Ed Cuttle

PRO Member
Was wondering what folks use to cut stave segments. Also, is there a plan somewhere to build a jig for the table saw, or do most use the bandsaw or compound miter saw? Would really like to try building a stave vase, but any info would be appreciated.
Thanks in advance!
Ed
 

Lloyd Johnson

Administrator
Staff member
Ed,
Depending on the effect you're after, you might try the 'wedge' method. Technically they are compound segments rather than staves. A stave is typically ripped from a board and a compound segment is crosscut from a board, but they can both achieve the same appearance.

The traditional method of cutting staves is to tilt the blade and set the miter at non-standard angles. It is difficult to get these angles set correctly and errors of 1/10th degrees is problematic. This is where the wedge method can be helpful.

If you want to add a compound segment ring where the slope is 40 degrees (for example), take a turning square of scrap wood that is 2.5" x 2.5" x 18" (or so) and tilt the table of your bandsaw to 40 degrees and cut the block lengthwise. You'll now have a wedge-shaped 18" length of wood that has three angles - 90 degrees, 40 degrees and 50 degrees. Use double sided tape to adhere this wedge to your miter fence. When you now lay your board on this wedge, it is already in its intended slope which means that you can now leave your saw blade perpendicular to the table top and set the miter at the standard number of degrees (15 degrees for 12 segments).

Before I do this, though, I take the board I'm going to use and rip the two long edges at the angle of 90 degrees minus your desired slope (90 - 40 = 50 degrees). I usually do this at the bandsaw. Once you have done this, you should be able to look at the end of the board and see a parallelogram. If you do this before cutting the segments, the ring made from them will already have a flat top and bottom and requires just a little effort to completely flatten it so that it can be added to the vessel.

The beauty of this approach is that a single wedge can be used for either a 40 or 50 degree slope or a 30 or 60 degree slope. I have three different wedges hanging on my wall and use them whenever possible.

Obviously, this won't work if the height of the ring is more than can be cut with your blade fully extended.

This process basically duplicates the process of cutting crown molding on a miter saw where the molding is tipped into its intended slope so that presets can be used to set the miter and tilting the blade is not required.

Lloyd
 

Ed Cuttle

PRO Member
Thanks for that insight Lloyd, I will give it a try. And I would guess that if I need a slope other than 40, or 50, just make another wedge to use on the miter fence for that degree. In my Woodturner Pro .wtp design, I have a stave segment ring that has a miter angle of 5.33 deg and blade tilt angle of 14.04 so then using your method I should make a wedge that will support the 14.04 degree tilt angle, correct? As always thanks for your help. Ed
 

Lloyd Johnson

Administrator
Staff member
Ed,

If you are going to use the Wedge method, I recommend using the ring type 'Compound' instead of Stave. Here is the difference between the two:

With the Stave ring type, you specify the upper outside and lower outside diameters and the height of the row and the software calculates for the Slope.

With the Compound ring type, you specify the slope, the upper outside and lower outside diameters and the software calculates the row height.

There is one thing that needs to change, though, if you use the Stave ring type and that is that the slope that is shown needs to be subtracted from 90 degrees. 90 degrees minus the slope shown is the angle of the wedge that you would make if using the Stave ring type. It is much easier using the Compound ring type as you can simply pick the slope you want to use.

I hope that helps.

Lloyd
 

Ed Cuttle

PRO Member
Again, Thanks Lloyd, I went and changed the two rings from Stave to Compound, and made some adjustments. Woodturner Pro defaulted to 40 degrees for the 'Desired Compound Slope' which will be supported by the 'Wedge' I will create as you mentioned earlier, correct? So in the Cutting Summary page, under Miter Angle, (which is 11.6 degrees) that is what I should set my table saw sled miter angle to for cutting the segments, correct, ignoring the Blade Tilt angle? Just need to be sure of all the cuts/angles.
 

Lloyd Johnson

Administrator
Staff member
Yes, using the wedge approach with the wood tilted in its target angle, you'll cut it as if it was a flat ring - no blade tilt and a standard angle.

It's always a good idea to make your first ring from MDF.

Let us know how it works for you.

Lloyd
 

Lloyd Johnson

Administrator
Staff member
Ed,

After re-reading your last post, I want to make sure it is clear about the cutting angles. If you use the compound ring type but then use the wedge technique, you need to ignore both the angle and the blade tilt calculations. If you have 12 segments in your ring, the miter angle is 15 degrees with no blade tilt -just as it would be if it were a normal flat segmented row.
Lloyd
 

Ed Cuttle

PRO Member
Again, thanks for the clarification, that makes more sense to me now. And I will take you up on the idea to run a test w/MDF. Will keep you posted, Ed.
 

Ed Cuttle

PRO Member
Lloyd, completed the MDF test and I must say, the segments matched perfect! What is your recommendation to mount the ring so you can even the bottom/top. I have seen some folks hot glue the ring to a faceplate MDF.
 

Lloyd Johnson

Administrator
Staff member
Lloyd, completed the MDF test and I must say, the segments matched perfect! What is your recommendation to mount the ring so you can even the bottom/top. I have seen some folks hot glue the ring to a faceplate MDF.

Ed,

You can see why I like to use this method when it makes sense. Evening the top and bottom partially depends on whether you did my other recommendation of cutting the two long edges at an angle before cutting the segments. If you did that, there is virtually no flattenting that needs to be done as it should be flat on the top and bottom already.

Regardless, I ususally use Cole Jaws on the wide end and then flatten the narrow end. I then glue the ring to the vessel using that flat surface and then turn the wide surface flat.

If I need to install the ring on a vessel where the wall profile is getting smaller, I'll use hot melt glue to mount the ring on an mdf disk mounted on a faceplate or use Cole Jaws in the expansion mode to hold the ring from the narrow diameter.

Lloyd
 

Ed Cuttle

PRO Member
Lloyd, having one problem. Now that I have a test design (a vase), my one ring that I have as a compound ring shows a desired compound slope of 75 degrees (ring #3) and not sure that my table saw will go high enough to do the cut for the board width. What do you do when this happens? Also, using the compound method, do I now need to have a cut board with the 75 degrees for the sled? Is there a way to get you the .wtp file so you can see what I am talking about. When I created the test ring as you recommended, the ring I did in MDF was for the upper ring, which was only a couple inches high/wide. Thanks for any suggestions/help. Ed
 

vrbradley

PRO Member
Lloyd,
Do you have any kind of a tutorial on using this wedge method. i'm in the process of trying to design a vessel with staves?
Brad
 
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