Posts: 118
Threads: 0
Joined: Jan 2003
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.
Posts: 12,926
Threads: 0
Joined: Jan 2010
Location: Lewiston, NY
(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.
There are several on-line calculators. For your application I think you need the N-Sided Pyramid. Here's an article on cutting the joints. Or you can build a sled for your TS that holds the parts at the correct angles.
John
Posts: 2,840
Threads: 0
Joined: Nov 2006
Location: Western NY
09-16-2019, 09:18 PM
(This post was last modified: 09-16-2019, 09:18 PM by Cecil.)
- Start with a squared up stick, i.e. 2x2x10
- Tilt blade to desired angle you want the sides of the container to tilt, nominal is fine
- Rip the stick to the angle (bevel on one edge)
- Set blade back to 90*
- Set miter gauge to angle necessary to make n sides, i.e. 6 sides, 30*
- Set the stick beveled side down and cut in two.
- There are now 2 gauge blocks
- Use the end of the stick to set the blade angle
- 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.
I tried not believing. That did not work, so now I just believe
Posts: 4,447
Threads: 0
Joined: Jan 2005
(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
Posts: 118
Threads: 0
Joined: Jan 2003
John,
That is great article with the built in angle calculators. Thank you very much. Chris
Posts: 22,248
Threads: 0
Joined: Nov 2002
10-18-2019, 02:51 PM
(This post was last modified: 10-18-2019, 02:51 PM by Edwin Hackleman.)
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.
Rip to width. Plane to thickness. Cut to length. Join.
Posts: 794
Threads: 0
Joined: Nov 2006
Location: Halstead, ks
(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.
Edwin:
Change the extension to something else. The recipient can change it back to .xls
Bill
Posts: 22
Threads: 0
Joined: May 2006
Location: NH
Here is a calculator that I use:
http://www.pdxtex.com/canoe/compound.htm
Regards,
Phil
Posts: 22,248
Threads: 0
Joined: Nov 2002
(10-18-2019, 02:58 PM)wjt Wrote: Edwin:
Change the extension to something else. The recipient can change it back to .xls
Bill 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?
Rip to width. Plane to thickness. Cut to length. Join.
Posts: 1,563
Threads: 0
Joined: Jan 2004
(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?
Get a Google account; it is free if you don't have one. Then upload the Excel document to Google Drive. Share the document and copy and paste the link here. Folks could then download it.
Alternatively, you could convert the Excel document to a Google Sheets document, share it, post the link here, and folks would use the calculator in Google Sheets without downloading it.
Matt
|
