An Imperfect Science

Here in the Library, we love a challenge.  When Larry and Anita Taylor contacted us about printing a replacement chess piece for their set, we welcomed the project.  Larry explained that one of his rooks had gone missing and he wanted to print a new one so he could continue to play.  He brought in the remaining rook and we got to work.

First we had to calibrate the scanner.  This process takes 10-15 minutes.  Makerware for Digitizer (the computer software that accompanies the scanner) walks you through the steps on your monitor.

Next up is the actual scanning!  We placed the rook on the turntable and the software walks you through the steps.  Each scan takes approximately 9 minutes, the sensor remains stationary while the turntable moves in tiny increments that allows the software to capture the item from every angle.  Multiple scans are often recommended, and merged together to create a more complete model.  For this project, we scanned the rook four times!

Sometimes a little extra editing is needed to make sure the model prints properly.  We used Meshmixer and Netfabb (both free downloads that can help edit and repair 3D designs) to remove any extra bits picked up in scanning and create a flat base for the model.

The missing rook was from the black set, so we changed out the filament (PLA or PolyLactic Acid - plastic) so the replacement rook would match the other pieces.  Changing the filament is an easy process that involves heating the extruder to melt the current color so it's easy to remove, then replacing it (still heated) with the new color.  

It is also important to level the build plate before you start a print.  This process takes 5-10 minutes and ensures that the surface is smooth and level for your print.  The display on the front of the Makerbot will walk you through the steps to level the plate.

Finally we were ready to print!  The scanning and set-up took about an hour and a half, including some trial and error.  When the model is ready, Makerware is the computer software we used to send the job to the printer.  Once that's done, it's a matter of waiting.  This print took approximately 2 hours and 15 minutes to complete.  Cost is determined by weight and this model's final weight was 16 grams, for a total cost of $3.60.  For comparison, the original rook weighs 73 grams.

As you can see, the print is not an exact replica.  This technology is still in it's early stages, particularly when it comes to scanning 3D objects.  But we are committed to the pursuit of learning, through trial and error if that's what it takes!