Angled and Mitered - is it possible

[simonmags]

Morning All,

My little pea brain is struggling this morning, I'm sure this must be possible but I;m struggling with the maths to work out the correct angles of cut.

What I would like to do is make a simple(ish) little chisel box, normal 45 degree mitered corners for the most part. The only twist is I'd like the sides to fall in at about a 15degree angle.

I started making a test piece out of ply last night, and the angles are close but the gaps are to large for decent glue joints currently.

https://lh3.googleusercontent.com/-jgJfAMfIPsQ/TwrJp5I1PMI/AAAAAAAAATs/8cWimNfzbEo/s400/IMAG0159.jpg

Any ideas on how to work out the correct angle of cut, or if this can be done?

Cheers

[HazzaB]

Hey Simon,

I have a project on the list, that requires the same or very similar sort of joins so I will be watching this thread with Interest.

HazzaB

[Ian Smith]

Gents,
Try this link Woodworkers Guild of Georgia, Miter Calculator (http://www.woodworkersguildofga.org/ShopHelpers/MiterCalculator.htm), otherwise just google compound mitre calculator.
Ian..

EDIT - According to the site linked above your angles are 10.55 and 45.99

[munruben]

Gents,
Try this link Woodworkers Guild of Georgia, Miter Calculator (http://www.woodworkersguildofga.org/ShopHelpers/MiterCalculator.htm), otherwise just google compound mitre calculator.
Ian..

EDIT - According to the site linked above your angles are 10.55 and 45.99Good link Ian. If you haven't already done so, I would put the link up in the forum library. :2tsup::2tsup:

[Billyboydes]

Hi Guys,
Here is a file I took off the Forum years ago.
regards

[Ian Smith]

Good link Ian. If you haven't already done so, I would put the link up in the forum library. :2tsup::2tsup:


Munruben,

Done! (in Conversions and Calculations)


Ian

[Billyboydes]

Hey Ian,
FYI the Web Site is wrong, their own PDF download is the same as my Excel.
regards

[Ian Smith]

Billy ,
I deleted my post because I misread the info - the spread sheet refers to blade angle and the web site refers to mitre angle - They are both right.


Ian

[AlexS]

Billy's one is correct. I think there's a later version of it which also does coopering angles already in the forum library. If not, just do a search on the WWF for compound mitre spreadsheet.

[joe greiner]

If the dimensions are small enough, and/or your miter box is large enough,

Cut the top and bottom bevels first. Set the board against the back wall of the miter box at its 15-degree angle, so that the bottom fits the base. Cut the normal 45-degree miter. Do all the right-hand ends, then reverse and do the left-hand ends; or vice-versa.

This also works for cornice moulding.

Cheers,
Joe