(09-16-2019, 06:46 PM)CCinOH Wrote: Any handy tips on how to cut a complex angle?  I am building an octagon shaped bird feeder with a sloped roof.  The 8 sections of the roof are essentially triangles.  They slope from the wide-end up to the peak. The angle I'm trying to figure out, and ultimately cut, is the long sides of the triangle.  As the triangles wrap around the roof, they have a slant to the side so they meet cleanly. 

Does anyone have any tips or tricks for determining the exact angle and then how to cut that on my table saw?

Thank you, Chris.

1. Start with a squared up stick, i.e. 2x2x10
   
   
2. Tilt blade to desired angle you want the sides of the container to tilt, nominal is fine
   
   
3. Rip the stick to the angle (bevel on one edge)
   
   
4. Set blade back to 90*
   
   
5. Set miter gauge to angle necessary to make n sides, i.e. 6 sides, 30*
   
   
6. Set the stick beveled side down and cut in two.
   
   
7. There are now 2 gauge blocks
   
   
8. Use the end of the stick to set the blade angle
   
   
9. Lay the stick on its side then butt the angled end against the blade.  Use this to set the miter gauge.
   
   no calculation.  You are making a gauge block.  It works great.

(09-16-2019, 06:46 PM)CCinOH Wrote: Any handy tips on how to cut a complex angle?  I am building an octagon shaped bird feeder with a sloped roof.  The 8 sections of the roof are essentially triangles.  They slope from the wide-end up to the peak. The angle I'm trying to figure out, and ultimately cut, is the long sides of the triangle.  As the triangles wrap around the roof, they have a slant to the side so they meet cleanly. 

Does anyone have any tips or tricks for determining the exact angle and then how to cut that on my table saw?

Thank you, Chris.

If you want something similar to a Geodesic dome then two angles are 45°. You will have 8 triangles with a base dimension and two legs 45° each. I would draw the walls of the bird house , all 8 sides. That will give you a base dimension , lets say for instance 10". Find center  which is 5" , and square that up past roof line. Now draw each 45° angle til both meet the centerline. Measure the lengths and you have dimensions for each triangle. Not positive but I think the compound angle is 22-1/2 °. I got this by dividing 360°  by 8 ,gives me 45° and half that angle is 22-1/2°.

mike

(10-18-2019, 02:51 PM)Edwin Hackleman Wrote: I built an Excel spreadsheet that I use all the time for cutting compound miter angles, but I cannot attach it here. .XLS file attachments are banned by WoodNet. Not sure why.

(10-18-2019, 02:58 PM)wjt Wrote: Edwin:

 Change the extension to something else. The recipient can change it back to .xls

 Bill

(10-21-2019, 07:39 PM)Edwin Hackleman Wrote: Bill, that does not work either. I tried renaming using three different file extensions and then no extension at all. WoodNet rejects them all. The host program apparently looks at the file and says "Forget it buster, not on our watch. You can't fool us. No Excel files allowed."

Any other suggestions?