Match boards with 60° angle

[Plupp 55122]

Hi,

I was planning to fit some planks that were all cut at a 60° angle, as shown at A in the picture. But as you can see at B, they don't fit together. Anyone have a smart tip on why it doesn't fit, I think it should!

 

[Tjacko]

When you cut the 45° angle, you should hold the plank as it is shown in the picture. I suspect you laid it down for better support than it provides on the small beveled edge it currently stands on. But keep it standing just as it should be when you make the 45° miter cut and you'll see that it turns out right.

 

[Micke184]

Are you sure it's cut at 60.00 degrees?

A "dubbelger" is very sensitive to deviations.

Measure the angle and post your result...

Error in thinking or "measurement error" - that is the question...

 

[Plupp 55122]

Hello again,

Thank you for your replies. Well, I've cut all the sides at 60° (or used 30°, that is). And if I position the piece upright when cutting 60°, the piece becomes straight and doesn't fit together at all.

The whole thing is in the shape of an equilateral four-sided triangle. So it has to be 60°.

If I were making a regular picture frame, it would have 45° angles and then no angle on the ends. But I want to raise it a bit. That's why I'm cutting the base at a 60° angle. And also the sides at 60°. This works fine. But then the question is what angle the ends themselves need.

 

[Sparkz]

Must have slept through the geometry lesson about the four-sided triangle...

But if I understand correctly, it's a square bowl with sides slanting outward at 60º? Like a pyramid with the top cut off and turned upside down? If so, you need to tilt the piece in the saw with the same angle it should have and set the saw at 45º.

 

[Tjacko]

I completely agree with sparkz's line, just as I wrote above. If it goes wrong, you have to keep it wrong when you saw.

But then the question is, is it a triangle or a square? (not that it should really matter)

 

[Plupp 55122]

Thank you for your tips, I held them up, standing on the beveled edge, works perfectly now, THANK YOU!

 

[Sparkz]

Glad it got resolved!
I thought of this thread when I stumbled upon a bunch of calculators, including one for exactly this. Check out CMITER.ZIP
http://www.myvirtualnetwork.com/mklotz/#math

 

[Tjacko]

Alright, I became unsure if I was really right. But since I was doing the same thing this summer and was going crazy before I got it right, I was quite confident in my case for once ;-)