WIMUv4 Packagaing from OpenSCAD Parametric Packaging Script v2

WIMUv4
This variant of OpenSCAD Parametric Packaging Script v2
http://www.thingiverse.com/thing:66030 is use to make a prototype production packaging for WIMUv4 devices

Author Mark Gaffney
Version 2.6L
Date 2013-11-04

To Do:

Fix internal radii no-of-sides when using chamfered package to maintain wall thickness  

Warning:

Some combinations of values, shapes and locations etc. may lead to an invalid or non-manifold shape being created, preventing you from exporting a .stl  
If this happens try to remove or change some of the features or values until you get a valid shape and then add them back gradually until you find the offending item, then change it so it doesn't cause a problem  

Note:

This thing uses  HarlanDMii's"write.scad" module http://www.thingiverse.com/thing:16193  
which you will need to have downloaded and located in the directory if you want to run this on your PC  
  
Generating text can be very slow!  
  
When generating a stacked layout it may look like the top is taller than it should be, this seems to be a visualisation bug in OpenSCAD, if you create a .STL it will be perfect  

Version Info:
WIMUv4 variant 2013
This variant is used to make a production packaging for WIMUv4

Changes from previous versions:
v2.6l
adjusted the interlocking features to try to give better bite on edge with large cutouts for switch and uUSB
v2.6k
moved and enlarged uUSB & switch holes to prevent fragile structures being formed on advice of i.materialise
moved lables for switch, uUSB and uSD from top to sides of object

v2.6j  
	added text for indicating switch on/off  
	added holes and guides for internal reset/bootloader-enable switches  
	added a hole for screw in screwpost  

v2.6i  
	packaging for WIMUv4 2013 version with small battery (same size as WIMUv3a and WIMUv3  
	began to fix a bug where interlocking features didn't generate in the correct location if the top_bottom_ratio wasn't 0.5  
		only implemented and tested for spheroids  

...for more information of previous version please see this thing's ancestor http://www.thingiverse.com/thing:66030  

Attention :

Copyright (c) 2013 Tyndall National Institute.  
All rights reserved.  
Permission to use, copy, modify, and distribute this software and its documentation for any purpose, without fee, and without written agreement is hereby granted, provided that the above copyright notice and the following two paragraphs appear in all copies of this software.   

IN NO EVENT SHALL TYNDALL NATIONAL INSTITUTE BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF TYNDALL NATIONAL INSTITUTE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  

TYNDALL NATIONAL INSTITUTE SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND TYNDALL NATIONAL INSTITUTE HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.