The Origami Forum

Hey everyone!

I am undertaking the very difficult task of folding Lang's recent Stag Beetle crease pattern. The grid is divided into 60ths but I don't know how to even start to divide the square into 30ths for that matter. I know that if I precrease a grid of 30ths, all I have to do is bisect or fold in half to get 60ths. Can anyone please show me the folding sequence to divide a square into 30ths? Thanks for you time in advance

Oruhito

Divide into 5. Divide each 5th into 3.
(You can also make it the other way round, first divide in 3 than each third into fifths.)
Now you have 15ths divide in half -> 30ths, divide in half -> 60ths.

Everytime when you have to make a larger grid and don't know how to get it, first make a prime factor division:
60/2=30
30/2=15
15/3=5
Proof: 5*3*2*2=60 and that is exactly what you have to do.

all you need to do is divide the paper into a 32x32 grid and cut off the extra strips to make it 30x30.

I'd do the 32 by 32 then cut....much less of a headache. 3rds into 5ths *shudders*

Thanks to all of you - equally good methods! I'm sorry for such an obvious question but I was tired and have a math disability so I often don't think too logically ha ha

Oruhito

http://www.flickr.com/photos/24738774@N04/

You could also use the Haga theorem to go right to 15ths: from the diagram on that website, use AP=7/8 and then BT=14/15, which you can use to get the entire grid. Just divide the 15ths in half from there. Hope I helped!

i always use reference finder when i undertake a task such as this. This program is freely available on robert kang's website http://www.langorigami.com/science/reff ... inder.php4

there is a new reference finder 4, however i believe that the only difference between its predecessors is the visual style of the program

Similarly to what Jonny suggested, you can go directly to 15ths using the first method on this page:

http://origami.gr.jp/People/CAGE_/divide/06-e.html

It will be much easier to deal with 7/15 (meaning the other side is 8/15).

[img]http://img360.imageshack.us/img360/7474/15thfk7.gif[/img]