I built what I thought was the ultimate segment jig only to figure out it was not accurate enough to make perfect joints. So after some deep thought sitting with the hens and sipping on a nice German beer it hit me square in the head what the issue is. The angle can be slightly off if you cut the segments correctly then the complementary angles cancel each other out. I modified my segment jig by removing the first angle guide and making the second on big enough for some Destaco clamps.

 

First I trim one to the angle

 

Then I use a scale to set the length to my stop jig

 

The stop jig overlaps the base so I put a bit of scrap under to lift the scale up

 

After setting the fence to hold the stop jig in the same place each time I flip the part and  set the cut and mark the right edge with an X

 

Ready to cut a segment

 

When you assemble the segments the X goes to a blank and the angles are perfect, only a rubber band is holding the segments in place. For glue up I use a hose clamp.

 

I'll add my segment calculator tomorrow in three flavors, excel, open office and a debian install deb.

 

JT

 

Edited January 1, 20233 yr by jthornton

This site may interest you.  They sell templates for setting both guides on your sled.  Other areas of the site show how they are used.

 

https://segeasy.com/toystore4.htm

Edited January 1, 20233 yr by HandyDan

Thanks!

I build the sled on my CNC mill so it's very accurate, at least as accurate as wood can be with humidity changes...

 

JT

Edited January 2, 20233 yr by jthornton

Like any theory you need to test it to see if it's correct or not. So on my segment jig I set the angle between 8 and 10 segments and cut some test pieces to see if my theory is correct on this jig or not. The test was successful and proved my theory is wrong!

 

 

 

I suspect on the other jig that uses the blade on a 22.5° angle that my theory is correct because each side is cut from the opposite side of the blade... sounds like I need to do another myth busters test.

 

I suspect the issue I had before was the crappy way I was setting the length, the new length stop using the fence as a stop is super accurate.

 

JT

Most everyone ends up buying the wedgies from the site I provided.  If you're doing a six sided disc you can use a 30°-60°-90° you may already have in the shop to set up your sled.  William Young had a forum site and a lot of the members were into the segments and the wedgies solved all their problems.  His site has been taken down so I cannot reference it for you.  Some have glued the pieces for the halves and then straighten the center plane and glue both halves together to overcome any discrepancies.

 

It turned out my CNC jig is accurate but my length was not as accurate. I've looked at those segment setting tools but they are not necessary when the jig is made on a CNC mill which is accurate to 0.0001".

 

I've used the make two halves and make then 180° when my length setting was not as accurate as now.

 

JT

I have a sled like the picture Dan posted. I made my own wedgies on my CNC. Very fast and easy to set up and very accurate.