Just for fun...a Penrose triangle

[eph210]

This is one way of constructing a Penrose triangle, also known as the impossible triangle.
This one is from one piece of cherry and is about 5" by 4.6" by 1"
Where is Mr Escher when you need him?

[cnc4me]

Love it !

[zeeway]

+1. Good job...confusing, but good.

Angie

[MTSO]

I like that a lot!, would love to see the crv file for that.

regards

Brian

[CarveOne]

I like this a lot also. It would make a nice linked chain circle as a wall display.

I once heard a rumor that said Mr. Escher's friends all thought that his thinking was a little twisted. I've always wanted to cut a model of the "Stairs". This one:

http://i.huffpost.com/gen/984718/thumbs ... -570.jpg?4

CarveOne

[kak]

Ok, how did you do it?

It looks cool, so I have been trying, but there is missing some material on the bottom side ( every corner).

I took the first half of material thickness, then mirrored the stl model and took half of the other side thicknes. It didn´t work.

[eph210]

I did that too on one I tried. I figured out that you don't mirror the model when you do the back. Only one file is needed, it ends up looking the same from both sides. You have to cut full thickness from both sides to make it work. I used some hot melt glue in the corners to hold it in place after I flipped it. The inside corners of the triangle have to be cleaned up by hand.
I have modelled it in Aspire now and it is a lot smoother than using the stl. When I get one completed I will post it.

Euan

[mezalick]

Thanks for the challenge.
I've been pondering this since you posted it.
Here's my version, made in Aspire.

It really stretches the imagination.
Michael

[eph210]

So I had a triangle model at my market today. That wasn't enough, now I am asked if I can make a circular version with a triangular cross section and one third turn per face. A bit more puzzling and I am close to having that one working.

I have attached the preview of the triangle I modeled in Aspire.

[mezalick]

Here's a shape to suggest...

[mezalick]

Or maybe something like this...
~M

[scottp55]

I just reached my "3 impossible things before Breakfast" Limit
You guys are making my head hurt!
LOVE the last one!
If you ever offer it for sale for us VCP8 guys, Might even BUY it so I could make one for the house.
scott

[eph210]

That last one is great. I will have to make a version to have on Saturday. Thanks for the inspiration.
This is my version so far. I am not ready to cut it yet as I am not sure it is a triangle cross section at the sides.

Euan

[CarveOne]

I'm with scottp55, my head hurts too much from looking at these simulations to figure out how to design and cut one of these. I'm sure that hallucinogenic drugs helps with the layout effort - but I'm not going there. I'd rather just buy the file ...

CarveOne

[kak]

Finally it worked.

Thanks for the advice, not to mirror the stl model. But still your first picture in the first post is my favorite.
I wonder how it looks in side view - like a zig zag?

The radius of my endmill was enough to keep the triangle in the material - I didn´t use hot melt glue. But I had tabs in the corners.
It takes some time to clean the inside corners. Im done with only one of them