# Angled Mitre Joints

Hi guys,

I'm trying to build an intergrated corner bench in my decking. Cutting the joins in the seats is an easy job making 45 degree angles as they are horizontal. The back rests for the benchs however are a bit more tricky.

If the back rests were vertical, again it would just be a case of again cutting 45 degrees. However I don't want to build posture correction benchs and so want to build both back rests at an angle of 10 degrees from vertical.

I have a compound mitre saw, but as I've dicovered it isn't just a simple case of rotating the blade to 10 degrees and pitching it to 45 degrees.

Can anyone tell me how to calculate the angles??

Thanks,

Alan
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117 views and no replies..!

Looks like you are all as stumped as I am!
AlGBarker
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hi ALG

Trying to get my head round what your on about!!

do you want the back rest supports 2 meet in the corner of the angle,if so u need a mega wide peice of timber so theyll join once compounded,and cut along the length at 45 degs with the 10 degs marked out along the height and cut each end at 80 degs and spin em round

if your goin 2 place the supports at 10 deg from the point where the seating slats and the frame meet at 45 degs, id suggest cuttin the 80 deg angle on the back rest upright timbers,and half jointing and bolting it to the horizontal frame of the seat....

im getting a headache.... :roll:

once youve done this then the point where the horizontal slats meet each other (theoretically as long as youve set the rest out right!!) should still be 45 degs..?!! cos theyre all sitting at the same angle so therefore not a compound mitre,its like an inverted hip on a cut roof....

i need a drink.... :wink:

hope this helps,easier to draw or make than explain,maybe a "sketch feature" would be a good app

mark
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Alan,

Is this (roughly) what you are trying to construct?

Google "slide.com/r/KXGvRL6W7z_syj6Ulzi03O811_Ck7S6q?previous_view=mscd_embedded_url&view=original"

ands lets see if I can embed it on the page....

Google "slide.com/r/KXGvRL6W7z_syj6Ulzi03O811_Ck7S6q?previous_view=mscd_embedded_url&view=original"

Mark
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Mark (Sweetorb)

Thanks for you reply... but I got a bit lost... I think I need a drink after reading it too! he he

Mark (hanger_on)

That's exactly what I'm trying to build!

If both back rests were verticle the 45 degree corner join in the horizontal slats would be easy, again if only one of the back rests was at 10 degrees and the other verticle. But because they are both at 10 degrees off vertical the angles go out the window.

Nice CAD picture by the way. Hope my finished product looks as good.

Alan
AlGBarker
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Hey,

The embedding attempt didnt really work as expected but you've found the picture. The CAD package is google sketch-up (free!).

Anyway the readings I have taken from the drawing are 7 degrees for the crosscut and 44.5 degrees for the bevel.

Can I suggest you try these settings on a couple of scrap bits first, just to check....

regards

Mark
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Mark,

This is brilliant. Thanks very much for your help.

All I have to do is make sure I set my saw up right now!

Alan
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