Cutting feature ring segments

B

bbrewer

Guest
I am using Lam Pro
I have glued up diamonds on my feature ring with a little space between the diamonds. My Repeating Unit is set for 2.5" which is the SEL for the segments and the segments match the Repeating Unit.
Now I am trying to figure out how to cut my segments without making them too short. Also I will be losing my space off the ends of the diamonds.
Would someone please explain what I need to do to get around this problem?
 

mfisher

Super Moderator
Staff member
Here is a couple of idea.
- glue your repeating pairs together. Cut off the dog ears to square up the segment block. Glue end pieces to the sides to give your border more space between the diamond and the surround material. Mark the segment block face down the center of the diamond. Mark the SEL line (left and right) sides of the block. Cut the segment block as outlined in the incra jig document.


You can reduce the width of the center strip when planning in LP. That increases the border width by making the diamond smaller.
 

Jim Morgan

PRO Member
You don't say how you normally cut segments. If you are using a wedgie sled to cut segments from a dimensioned stick, the stick rides on the jig, and the segment is the offcut that falls to the right of the blade. This is reversed for the sort of feature ring segments you are constructed: the segment rides on the sled, held by the fence and a stop block, similar to the set-up in the incra pdf. Cut half of the segments on the top fence with the face side of the segment towards the fence; cut the remaining segments on the bottom fence with the face side of the segment away from the fence. For each of the segments in one half, cut one edge roughly to length. Adjust the stop block, flip the segments over (keeping the same surface on the fence), and trim to exact SEL. Use masking tape shims to make fine adjustments: purple (delicate) tape is 0.002, blue (painters') tape is 0.004, and yellow (masonry) tape is 0.006.
 

Lloyd Johnson

Administrator
Staff member
If your target SEL is 2" and you are going to lose 1/8" when you cut the board of repeating units into individual units, you should do one of two things. First, you could add 1/8" to the Segment Edge Length to provide the wood that will be lost but that is not how I do it. I use the second method to add back the lost wood. To do that , hold your angled cuts back 1/16" from the front edge of the segment as you will see in the following diagram. This will turn a SEL that is 1-7/8" to the equivalent of 2" once you turn the ring round. It will also let you set a stop to make your first angled cut and then flip the segment over and against the stop to make the second cut.

I always make my cuts this way so I don't have to remember to add 1/8" to the SEL and instead just use the dimensions shown in the Summary.
(This is a top view of the segment)

Cutting angles on segments that are too short.jpg
 
B

bbrewer

Guest
Hi guys,
Thank each of you for your great replies. They are all very clear. One big help was to not cut the bevels from a strip, but to cut them individually. I was trying to figure out how to cut from a strip and be accurate.
Do you have a height to width ratio that you find is pleasing to the eye?

Thanks again for your help.
 

mfisher

Super Moderator
Staff member
I really don't have a recommendation for the height / width ratio for a featured ring. It is whatever is pleasing to your eye.
Depending on the shape of the vessel I tend to put the featured ring center at the golden ratio level.

One thing to keep in mind is SP will put the featured ring at the widest part of the vessel. In WTP you can put it at any location.
 

Lloyd Johnson

Administrator
Staff member
One thing to consider is when you cut the angles on the segments, the inside of the bowl should look as good as the outside so make sure you don’t cut into the design. If you transfer the design back to Segment PRO you can scroll in through one side of the bowl and see what the design will look like on the inside of the other side of the feature ring.

To keep from cutting into the design, increase the width of the center strip that will be removed. When you increase that width, the width of the design decreases. You can also change the angle of a diamond (for example) to change the width of the design.

I believe that the height/width relationship is less important than the finished result. If the inside/outside of the feature ring looks good and the accuracy of the cuts and assembly is good, any other considerations will not have much meaning.
 
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