# Complex mitring



## adzm124 (3 Nov 2006)

Hello, I am trying to find a way of accurate mitring for a 3d shape in wood, to do a cast from in concrete. Best way to describe it is like the pizza hut roof symbol. Is it as simple as to cut the angle on the mitresaw the same as the edge cut? New to this wood-stuff, so technical words escape me! Sorry. Does this make sense? It's the mitring of the upright 4 sections causing problems, as they lean-in to each other


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## SketchUp Guru (3 Nov 2006)

I had to look at the Pizza Hut logo to figure out the shape. So are you wanting to end up with a piece of wood that is shaped like that in 3D or are you looking at making a negative version in wood?


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## SketchUp Guru (3 Nov 2006)

Like this?


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## SketchUp Guru (3 Nov 2006)

Or this, rather?





If you are using this for a mold, you should be able to get away with simple butt joints instead of mitres. I would cut the end pieces as desired and nail on the long ones. Then I would trim the long ones flush to the short ones.


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## JFC (3 Nov 2006)

Isnt that a hipped barn end roof .


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## Newbie_Neil (4 Nov 2006)

Hi adzm124

Welcome to the forum.

Cheers
Neil


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## adzm124 (4 Nov 2006)

Thanks Dave R, that's the kind of shape, I see your method for that shape and it's a good solution for it, but we also will make a hexagonal shape in 3d, which leans inwards towards the top - how do you calculate the angles to cut? As cannot butt up on some pieces.
For example: with a 90º mitred cube the two angles are 45º.
If wood leans at 36º inwards towards top, instead of straight up, what is calculation to find the angle of mitre-cut? 
Confusing eh?


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## Nick W (4 Nov 2006)

If you have a Palm PDA you can use the compound mitre function of Woody


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## SketchUp Guru (4 Nov 2006)

Calculating the angles for compound miters generally requires some trigonometry. Or you can use a calculator such as the Excel-based one that you can get free here. Or, if the angle you want is shown, a table.

And where were my manners. Welcome to the forum.

Edited to add: Nick did better in his typing class that I did.


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## adzm124 (5 Nov 2006)

Thanks for the welcome and thanks very much for advice from all, you have been very helpful, downloaded the excel program, makes it easier to undertand. The hexagonal one we are about to do would have made my head explode.
It's only for some rubbish plywood, to make a concrete cast of a japanese 4 tier tower - should I be saying this on a woodworkers forum? I'll post a pic when we've done, if anyone wants to see it.
Just getting in to woodturning and projects, we have moved from uk to france, and need to find out where we can get decent wood, chestnut, maple etc. Thanks muchly, I'm sure i'll have other questions - sorry!


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