A Dangerous Size

Printing an 11 x 14 inch sheet on the Epson 9900 involves a ticklish problem: the paper jams against the roll cover. This crumples it top and probably bottom, where the crumpled paper can hit the print head. This could damage the print head. Collisions can happen both when the paper feeds for the first time, when it moves up and down as the sensors on the head measure and position it, or when you start printing, and it again adjusts up and down.

Fortunately, the solution is simple. You can hover over the printer, gently guiding the top edge of the paper with your hands, though that isn’t the best solution. Holding or taping another piece of paper onto the roll cover behind the sheet works better. You could also leave the cover in raised position, but then you wouldn’t have it to guide and support the sheet.

protected printer

Paper taped to roll cover

Bitmap to Surface to Model

Bitmaps can be used as height fields for a 3D terrain. Typically, the brighter the pixel value, the higher the terrain at the location mapped to the pixel. A 3D grid such as a terrain model can be output as cross-sections and created in any convenient material. The Processing app included with this post will do the whole process for you: open a bitmap, display it as a terrain model, and output cross-section profiles to a PDF file. The profiles include slot marks. Once you cut out the profiles and the slots, you can fit everything together into a model. The model can be used to construct a mold for the surface.

Let me explain this with pictures. First, here’s what the assembled model looks like:

The assembled model

The assembled model

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