DobloFactory

Copyright (c) 2013 Daniel M. Taub Copyright (c) 2010 Daniel K. Schneider

This file is part of DobloFactory. DOBLO: DUPLO-compatible scenery factory

DobloFactory is free source: you can redistribute it and/or modify modify it under the terms of the CC BY-NC-SA 3.0 License: CreativeCommons Attribution-NonCommerical-ShareAlike 3.0 as published by Creative Commons.

You should have received a copy of the CC BY-NC-SA 3.0 License 
with this source package. 
If not, see <http://creativecommons.org/licenses/by-nc-sa/3.0/>

NOTE THIS FILE MAY BE OUT OF DATE test-foo.scad files are good documentation for library components.

Read down to understand how to use this. Documentation (similar as here, but more readable) http://edutechwiki.unige.ch/en/Doblo_factory

Download:

• http://www.thingiverse.com/thing:2106

BUGS, missing pieces, other things to do:

• cyl_block nibbles can't handle top_r < 2 and rational numbers
• a pilar with both supports for bottom and top (i.e. 2x4 directions)
• replace support by triangle_forward, triangle_right, etc.
• Lego brick heights work in multiples of 3 (Duplos is multiples of 2)
• test STL merging with both Lego models

Authors:

• Daniel K. Schneider, TECFA, University of Geneva, March 2010
• refactored by Daniel M. Taub, CEMI.org, October 2012, January 2013
• based on parametric lego duplo (http://www.thingiverse.com/thing:1778) by Domonoky
• based on OpenSCAD Bitmap Fonts Module (http://www.thingiverse.com/thing:2054) by Tony Buser.

This code is derived from two original works:

1. Domonoky's parametric lego duplo - http://www.thingiverse.com/thing:1778. I got the idea, and then kept some of the fine parts (nibbles, walls, etc,)
2. Tony Buser's OpenSCAD Bitmap Fonts Module - http://www.thingiverse.com/thing:2054

Legal disclaimer:

• This is not Duplo(TM), it's called Doblo and it just happens to fit more or less.

Purposes:

• Creation of 3D duplo-compatible "play" boards for various purposes from Kindergarten to Master level
• Introduction to 3D environnment (learn about positions) and use of OpenSCAD
• "End-user 3D programming" environment (e.g. students could add other primitives)

Coordinate system: We use a column/row/up grid, each x/y cell corresponds to a DUPLO/Lego nibble

• col = x-axis
• row = y-axis
• origin is at x=0 and y=0, default bottom of bricks is z=0
• each block module starts from left/back ("upper" left corner)

units for col/row and width/length:

• 1 DUPLO row (16mm, i.e. half a 2x2 block)
• 1 LEGO row (8mm) units for up and height:
• DUPLO: 4.8mm, i.e. a 1/4th of a typical duplo 19.2mm 2x2 block
• LEGO : 2.4mm, i.e. a 1/4th of a typical duplo 19.2mm 2x2 block. Should be rather 1/3 (3.2mm) but I can't change this easily without breaking stuff (castles)

Software needed:

• http://openscad.org/
• http://en.wikibooks.org/wiki/OpenSCAD_User_Manual Once you installed openscad, then you may have a glance at the manual. Otherwise, just know this:
• To compile a .scad file (see the result)
  1. Menu: File->Open
  2. menu: Design->Compile
• To render for real and to export
  1. menu: Design-> Compile and Render (CGAL) .... this can take many minutes.
  2. menu: Design-> Export as .STL

Usage: (1) Create a new .scad file or start from doblo-factory-examples.scad (2) Import this file: include doblo-factory-1-2.scad (3) Set the SCALE variable !!! (4) Then, either write custom modules to create any combinations of block forms and imported STL or use the merge_brick standard module to pile up 3 objects: a doblo, a block and one imported STL

See examples in the file doblo-factory-examples.scad

Printing:

• To print larger structures be aware of warping, e.g. make a fat sticky raft and/or use cooling and/or print with PLA.
• If you need good DUPLO compatibility, you will have to print with small layers !
• Large structures can take many hours to print.

To create your own more complex custom shapes, there are several modules (functions). For example:

(1) The doblo brick. Typically, to create a DOBLO base (you also can pile them up (union) but may lead to a waste of plastic. Doblo bricks are just like Duplo bricks, however you can make the nibbles on top optional.

module doblo (col, row, up, width,length,height,nibbles_on_off)

(2) Merge STL files Positions an stl file, you may have to find out by trial and error what z offset to use. Tip: embed the STL into a doblo or a block. module merge_stl (file, col, row, stl_z_offset_mm)

(3) Blocks and base plate To create a building block for larger structures with x,y,z positioning. A block doesn't have nibbles underneath and may or may not have nibbles on top.

A base plate will have some grid underneath, because printing large flat blocks is usually very difficult. Using "up" other than 0 doesn't make much sense.

module block (col, row, up, width,length,height,nibbles_on_off) module base_plate (col, row, up, width,length,height,nibbles_on_off)

(4) Nibbles. To insert nibbles on some spots of a nibble-less block or an imported STL. To used in larger structures.

module nibbles (col, row, up, width, length)

(5) Bottom nibbles To insert underneath an imported STL. Not very usefull I think, I'd rather stick a doblo block to the feet of an imported object.

module bottom_nibbles (col, row, up, width, length, N_height)

(6) Support triangles Support triangles are used in larger structures to support a roof. Thickness = 1 doblo width, e.g. = PART_WIDTH. Sometimes you may want rational numbers. E.g. 1.5 Height/length proportion is 4.8/4 (i.e. typical Lego proportions). Only use angle arg of 0,90,180,270 !!

WARNING: you may want to have these overlap a bit, e.g. if 2 corners are just touching, the model will be not simple and can't be exported as STL. In other words, make them a bit higher (embedded into the block that you will put on the back and the top of the triangles anyhow. See the stronghold example included. __ |

module support (col,row,up,height,rotation_angle,thickness)

(7) ramp Is the opposite of the support triangle, but with a flatter angle. Can be used to achor a high and slim block or also to build a real ramp (then you might place 2-4 next to each other.) Height/length proportion is 4.8/16 (i.e. typical Lego proportions)

module ramp (col,row,up,height,rotation_angle)

(8) Cylinder Is like a block, but round, i.e. meant to used for larger structures . Can have nibbles on top.

module cyl_block (col, row, up, bottom_r, top_r, height, nibbles_on_off)

(9) Glyph Adds a character, based on http://www.thingiverse.com/thing:2054 Size: fits on a 2-x2 doblo unit height_mm is height in mm. Typically between 2 and 4

module glyph (col, row, up, height_mm, char)

(10) Text Adds a text, based on http://www.thingiverse.com/thing:2054 Size: fits on a 2-x2 doblo unit height_mm is height in mm. Typically between 2 and 4

module text (col, row, up, height_mm, chars, count)