learning the ropes

One of the tricks to getting an object printed properly is making sure that it adheres to the heated build surface.  Sometimes, it seems that this requires enabling the “raft” to prevent a thin section of a part from pulling away from the build surface.

Another trick to getting an object to adhere to the build surface is to make sure that the initial extrusion (which the gcode generated by ReplicatorG refers to as an “anchor”) does not become a blob that the extruder nozzle drags around the platform during the first few layers of a build.

From the time of its first testing, Makerbot #2 head never positioned the extruder nozzle above the silicon wiper at the beginning of a build, so it was always necessary to snag the anchor with a pencil or pliers to make sure it didn’t get pulled along by the nozzle.

The “start” section of the gcode that ReplicatorG generates contained some notes about this — and after tweaking a very short gcode file to discover the proper coordinates of the wiper, the next big challenge appeared: which file to modify.  The file which ReplicatorG notes in the comments of the gcode it generates indicated one file, but after combing through a bunch of start.gcode files, it was ultimately determined that the correct start.gcode  file was [ReplicatorG install path]\machines\thingomatic\start+HBP+Stepstruder.gcode

If ReplicatorG is installed on a different workstation, start+HBP+Stepstruder.zip should be unzipped and copied into the above file path to properly home and wipe Makerbot #2.

1. Verify that Thing-O-Matic is powered on and connected via USB to computer.
2. Start ReplicatorG
   1. Check Machine -> Connection to verify that the correct serial port is selected
   2. Check Machine -> Machine Type to verify that the correct machine type is selected.
      1. For Thing-O-Matic #1 this should be “Thingomatic w/ ABP and Extruder MK6″
      2. For Thing-O-Matic #2, this should be “Thingomatic w/ HBP and Stepstruder MK7″
3. Load up a model (either from a .gcode file or from an .stl file)
4. Make sure the part is touching the build surface
   1. Select “Move Object” on right control pane
   2. Click “Put on Platform”
5. Click the “Build Object on Machine” button (first button on the left).  The device will home itself and then after a warm-up period (30-40 seconds), will begin printing.  You may need to wipe the initial anchor extrusion (a blob before the object’s outline is drawn) so that it doesn’t get in the way of the print.

In order to document the sensor apparatus for students to understand, I had planned to draw a schematic in Eagle. Last night, I ran across Fritzing, though, and thought I would give that a try. The results are edited a bit. Fritzing didn’t have a part for the magnetopots, so I drew one — hoping to create a part out of it. Unfortunately, when I tried to follow the part creation procedure, I found that the Fritzing part template file appeared to have slightly less that 1 mil hole spacing, so it wasn’t compatible with the part I drew. Bummer, but maybe it saved me some time in the end?

I wrote two programs which demonstrate the basic workflow necessary to create a movie with a transparent background.

transparent_png_writer_bare.zip contains a Processing sketch which writes out a variable sequences of .png files with a transparent background.

framewriter is a Max patch that loads all of the .png files in a specified directory and dumps them frame-by-frame into a .mov file encoded using the “Animation” codec (which supports transparent backgrounds).

Quick visual documentation of drawer sensor build process.

MagnetoPots from SpectraSymbol