Tuesday 13 March 2012

Mendel90 files

I have put the Mendel90 files on GitHub. There is the OpenScad source code plus some Python scripts that, given a machine configuration, will generate all the STL files for the printed parts,  DXF files for the sheets, SVG drill templates, a master BOM with a matrix showing where the parts are used and sub-assembly BOMs for each of the sub-assemblies.

Two standard configurations are included: Sturdy90 is the MDF version with 10mm rods that I have had running for three months. Mendel90 is an acrylic version with 8mm rods and the same build area as a Mendel that I have assembled but not run yet. The generated files for these two configurations are also on GitHub.

The directory structure is as follows: -

├───imported_stls       The pulleys and gears that I use but don't have OpenScad source for.
├───mendel                 Generated files for the Mendel90 variant.
│   ├───bom
│   ├───sheets
│   └───stls
├───Prusa_retrofit       A Z motor bracket that allows the Mendel90 x-axis to be fitted to a Prusa.
├───scad                    The OpenScad source.
│   ├───conf               OpenScad configuration files.
│   ├───utils                Utility modules for making objects, such as polyholes.
│   └───vitamins          Models of the non-printed parts.
└───sturdy                  Generated files for the Sturdy90 variant

The top level directory contains the build scripts. To make all the files for a machine run: -
    make_machine.py machine_name

To make just the bom, sheets or stls run bom.py, sheets.py or stls.py machine_name.

machine_name can be mendel or sturdy. To make your own variant copy scad\conf\mendel_config.scad or scad\conf\sturdy_config to yourname_config.scad and edit it. Then run make_machine yourname.

To view the model of the whole machine open scad\main.scad. It will take about 8 miniutes to render but after that you can pan and zoom it at reasonable speed and changes takes less time to render.

To view a sub-assembly open the individual scad files. Set the exploded flag in config.scad to make exploded views.

scad\conf\config.scad contains constants that should be independent of machine variant, for example screw clearance hole sizes. It includes machine.scad that is generated by the build scripts to include the configuration for the specified machine variant.

Thanks to sevikkk (Vsevolod Lobko) for making the scripts work on Linux as well as Windows.

I will put the build instructions in the RepRap wiki soon. These will mainly consist of the exploded views of each of the sub-assemblies with the list of parts in it. Unfortunately OpenScad can't export images from the command line at the moment so they have to be made manually in the GUI.

On my todo list is to add scripts to make images of all the STL files, PDFs from the SVG files using inkscape and produce the BOMs in spread sheet format using OpenOffice. I also need to write a script to tile the SVG files to allow them to be printed on A4 sheets and taped together like the Darwin bed template.