Tag Archives: robomaster

From Blender to Pepakura to Corel Draw to CraftRobo

2011-05-08

Blender is an excellent open-source 3D modelling application. Pepakura Designer (short: Pepakura) is a very useful tool for papercrafting, which converts 3D models to 2D templates which can be printed on paper, cut and assembled into the original 3D model.

The two are a great combination for papercrafting. In fact, I found the combination of Blender for 3D modelling, Pepakura for unfolding, Corel Draw for postprocessing, adding artwork and finetuning, and finally CraftRobo for cutting perfect. Here is the complete workflow:

First, you need to export the Blender model to the 3D Studio format understood by Pepakura.

Go to

File > Export > 3D Studio

then save the file. Then, simply open the file in Pepakura. Once you have created a satisfactory 2D pattern, the next step is to get it into Corel Draw. There are several vector export formats available in Pepakura, however all of them have some problems. I found the best one to be DXF (AutoDesk’s ‘Drawing Interchange Format’).

In Corel Draw, click on

File > Import

then select ‘DXF AutoCAD’ as file type and select the file exported from Pepakura. You will then be able to place the file into your existing page, by pressing LMB and dragging the mouse until the shape has the correct size.

Note that the DXF format separates the shapes for folding and cutting into different layers, which are preserved in Corel Draw. This is very convenient when you want to process them differently (such as assigning them to different cutting types for the Craft Robo).

One important drawback of the DXF format is that Pepakura chops up the outline of a shape into individual edges. This can be difficult to work with in postprocessing. Therefore, another option is to use the EPS format. Here, you need to carefully c0lor all cutting edges in the same color in Pepakura. This will create a contiguous outline in the EPS file. Unfortunately, the EPS file does not preserver the color information itself, so all edges – folding and cutting – are black, and you have to separate them manually.

You can now add artwork and edit the shapes, if necessary. Once that is done, you can simply send the file off to the Craft Robo for cutting. I keep the folds and cuts in different layers (see above) and assign the following cutting parameters:

Folds: Index 90lbs paper, 10cm/s, force 30, line type: Custom 1 (0.120 cm a, 0.120 cm b), Passes: 1

Cuts: Index 90lbs paper, 10cm/s, force 30, line type: 1, Passes: 2

Converting CorelDraw to GSD files

2011-02-19

Craft Robo’s aptly named control software Robo Master uses a proprietary file format ‘GSD’. I work with CorelDraw, and while CDR is perfect for cutting directly (and in my opinion much better suited for complex Craft Robo projects than Robo Master), there is no way around the GSD format if you want to pass on designs to other people.

The way I do the conversion is as follows:

First, I split the art to be printed and the cutting outlines. The art to be printed goes into a PDF file, and the cutting outlines into a GSD. The reason behind this is that complex artwork does not convert correctly to GSD – only very simple shapes do.

Now, in order for this to work we need to make sure that the registration marks are included in the PDF and that they align with the registration marks used by Robo Master.

I have prepared a Corel Draw file with registration marks at the exact same positions as the default positions in Robo Master.

Using this file, these are the steps I follow:

  1. Position the artwork and cutting outlines inside the registration marks
  2. Move the cutting outlines to an invisible layer or delete them temporarily
  3. Export the document as a PDF
  4. Make the cutting outlines visible again or restore them. Delete everything else (make sure that the cutting outlines are ungrouped and are all in a single layer. This should be the only layer in the document)
  5. Due to a bizarre behaviour of Robo Master, where imported DXF files have their center at the lower left corner of the page, we need to add an offset to the outlines. Go to ‘Arrange-> Transformation -> Position’, and enter 148.5 and 105 mm (half the page size for an A4 page). I have prepared a macro included in the template mentioned above you can use for that: Go to “Tools -> Visual Basic -> Play” and select RecordedMacros.dxfoffset
  6. Now go to “File -> Save as…”, select as file type ‘DXF – AutoCAD’
  7. In the AutoCAD export window, select “AutoCAD R13″ as the export version, and select “Millimeters” as the export unit.
  8. Open Robo Master, go to “File -> Load DXF…”
  9. Save the file as a GSD file.