Cutting compound angles?

[logwalker]

You are over simplifieng the problem. Your pyramid when viewed from above will show 45 degree angles but, the miters that are needed to fit the four sides will be 30 degrees.

[Radar67]

To get a square or triangle, you have 360 degrees to deal with. A triangle will have 120 degrees at each joint (60 degree miters), a square will have 90 degrees at each joint (45 degree miters). The taper only makes a smaller square at the top of the post, not a triangle. A tapered square post is cut with 45 degree miters. A taper jig on the table saw will cut the best joint for this purpose. Roll the blade over to 45, set the taper jig to the line on your stock and cut. First, cut your board to the length you want, then use a center line to lay out your pieces. Mark your bottom to you width, mark the top to your width, connect the dots and you have the angle of the taper to set your taper jig with. Easy enough?

[logwalker]

OK, build a tapered column with a 60 degree taper. Cut the miters with a 45 degree angle. Now try and get them to fit tight. I am sorry but they won't. If you don't believe me then try it. You only need to cut two sides to see how far off they will be.

Joe

EDIT: What everyone seems to be missing here is that this is a compound angle. That means two angles coming together and creating a new and different angle.

[SwampDonkey]

Joe, my response was only to your Pyramid analogy. ;) I've never cut a tapered post so I can't answer this problem.

[logwalker]

The pyramid is the same problem. If it has 45 degree angled side then the miters on the corners would have to be 30 degrees.

[jamesamd]

Not sure what I'm seeing there,James

Lud  ;D
The front board and the top board both are 5 1/2" on the ends.They were tapered in a gentle curve to 4 1/2" in the center.Both boards have blocks and shims under them to bend the boards on the ends 1" (up/out) the centers are on a square piece of timber,flat against it.
I made a quick template by hand out of MDF,jigsawed=sloppy but it worked.
If My Son want's to make them for His house,Iwill have 1=one=uno=ein template made of 1/4" alum.
at a shop that has a CNC router and then route 45's on each edge. ;)Worked for Me!
Jim

[jamesamd]

So,LW.What are the results? With Your tapered colums!!!
I am very curious.
Jim