3D snowflake

 From:  bemfarmer
8221.1 
http://www.handimania.com/diy/3d-paper-snowflake.html

This is a cylindrical model, in MoI, of one sixth of a 3D snowflake, typically
made by cutting concentric squares out of a square of paper.
Paper snowflakes were observed on the ferry.

The model is essentially that of wrapping two concentric squares,
around a cylinder, at 45 degrees, i.e. the squares are oriented as a diamond.
The wrapping effect is created by using the Helix command.
(Flow was used to figure out the helix parameters, and did a fair job of modeling, but was not used for the final model.)

Dimensions are scaleable. The dimensions and other parameters used are as follows:
The two concentric square diamonds have diagonals of 2.25 and 1.75,
for an average of 2, which is the pitch and axis length of the basic helix.
The radius of the helix is 1/PI ~= 0.3183099. There is one turn.
The reverse twist helix is also created.
The two helices are moved axially by 0.25 units, self trimmed, joined,
and used to trim a cylinder.
Once this single pointed "figure-8-like wrap" is completed, scaled copies are made.
This model has 3 cylindrical sections.
The middle cylinder was rotated 180 degrees.
A 4th smaller section could be added in the middle.
Offset shell was used.
Circular array can be used.
Paper modes have a little bending adjustment to combine into a six sided snowflake.
- Brian

EDITED: 25 Nov 2018 by BEMFARMER

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