learning the ropes

things I made at ITP and after: sketches, prototypes, and other documentation

Thursday, April 26, 2012

Initial Wipe Fix

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.

posted by Michael Chladil at 1:46 pm  

Tuesday, April 17, 2012

Your First Print

  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.
posted by Michael Chladil at 2:47 pm  

Thursday, April 5, 2012

Makerbot Specifications / Status / Preparation

Two Makerbot Thing-O-Matics

Thing-O-Matic #1 (4391 )

  • Stepstruder Mk6+ (configured for 3mm filament)
  • Motherboard v2.5 (with Arduino 2560) – firmware v3.1
  • Automated Build Platform
  • Extruder Controller board v3.6 – firmware v3.1
  • Spindle kit (missing feed tube)
  • Calibration
  • Modifications
    • Stepper shafts ground to accommodate pulleys (probably need to replace steppers since pulleys don’t spin true)
    • Location of Z- and A-axis control boards swapped on mounting board to accommodated shipped cable lengths.
  • Issues
    • Extruder jamming – originally, unit was assembled with 3mm filament capability.  Tried to run 1.75mm filament through it before realizing this, which jammed the extruder.  After several cycles of taking apart and reassembling the extruder, I rebuilt the unit with 3mm capability and “repaired” the tip of the  PTFE tube that guides the filament through the heater.  Ultimately, we should order replacements for both of the filament tubes.

Thing-O-Matic #2 (tag 6776) — operational

  • Strepstruder Mk 7 (using 1.75mm filament)
  • Heated Build Platform
  • Motherboard v2.5 (with Arduino 2560) – firmware v3.1
  • Extruder Controller board v3.6 – firmware v3.1
  • Calibration
  • Modifications
    • Left side cutout for power supply modified to accommodate Makerbot’s change in power supply part geometry.
    • Heated Build Platform Strain Relief to prevent damage to HBP cables.
posted by Michael Chladil at 11:20 am  

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