The Modular Castle Kit - Lego Compatible is a kit to assemble Lego compatible modules into castles and strongholds. You can print just one, several or all components and then play at castle construction, mixing in your own Lego. You can hook together modules like in the picture used to advertise this thing (use simple Lego bricks as connectors) or you can create much wilder "mix with any Lego" structures or you could create a village with different buildings. Some modules are designed to be stacked on top of each other.
There are three types of components:

(1) modules with an easy to print base plate,
(2) modules with a Lego-compatible base plate (stackable)
(3 lighter stackable versions (better vertical fit, faster print, but require a solid 1st layer)

I printed most, but not all of the modules. However, I then also made some minor changes to most of the printed ones and there still may be a few minor glitches. Please examine a thing before you print it.

Slicer and printer settings

Tune your settings with the included standard 4x2 calibration brick. Make sure that the first layer sticks well, in particular when printing Lego-compatible bases (nibbles underneath). A few things to to:

• Make your first layer 125-150% or something that is equivalent. Most platforms are uneven (0.05mm waves do have an impact) and you will have to compensate for that.

• Add glue to the platform (e.g. Pritt extra strong) or hairspray

• Add 10 degs or more to standard printing temperature, e.g. PLA at 205

• Move the print head closer to the platform, e.g. for my self-calibrating printer I add this to the end of the start code: G1 Z-.05 F3000 or sometimes G1 Z-.1 F3000. On a non calibrating printer, place two sheets of paper on the bed and make sure that the print head can move the upper sheet in every position, but without scratching

• You could use a raft for the modules that have 2x2 Lego feet, but removing these is a pain...

Speed:

• Go very slowly for the first layer (about 15% of your normal speed).

• Go slowly for the second layer (if your slicer allows, e.g. Sli3r does not)

• Medium speed for the rest, e.g. 50mm/s or faster

Shells and layers:

• 3 shells

• 4 top layers (3 also can do)

• 3 or 4 bottom layers.

One tower takes about 6 hours to print with these settings. I do not recommend printing with lower resolution because wait will be longer. If you print modules with a base plate, you can easily print 4 towers at the same time, in about a day.

Fit with real Lego (TM) and tuning

Fit is about right for printing with 0.25 resolution and medium-fast quality printing. The blocks are maybe a bit too tight for fit with Lego. In that case, heat the piece with a heat gun (or maybe a strong hair dryer), then gently press onto Lego (TM). If the fit is too loose, change the slicer settings (or much better, generate your own version with OpenSCAD, see below).

OpenSCAD code / tuning / creating

This kit was made with an OpenSCAD library called Doblo Factory. I created a first version in 2012 that was refactored by Daniel M. Taub (2012/13). Since then I made a few minor changes. The version you should use (it includes this castle kit) is available as a zip file: http://tecfa.unige.ch/guides/3dprinting/doblo-factory/

Here, I only included the scad file that generates these blocks. It provides a list of the models. A typical tower includes mostly about 20-30 function calls, generating Lego block elements plus some openScad "hand code".

If you download the full Doblo Factory code (http://edutechwiki.unige.ch/en/Doblo_factory, also see the URL in the scad) file, you can:

• tune dimensions, e.g. various Lego-compatible nibble and wall thickness parameters (lib/doblo-params.scad)

• produce DUPLO structures instead (SCALE=1;) (example_castle_kit/castle_generation.scad)

• create your own castle modules (ext/castle-kit-2-0.scad)