Steps to operate MakerBot Cupcake CNC

This is a work in progress and needs have more details filled in.

Computer

The MakerBot is connected to a computer using a USB cable.  Currently, this is the Dell Dimension 3100 located beneath the bench with the MakerBots.

The computer requires the following:

• Power
• Keyboard
• Mouse
• Monitor
• USB port
• USB cable
• ReplicatorG (program to run theMakerBot)

Preflight Check

Before getting started, take a look at the MakerBot and make sure everything looks okay.  Check the tension on the Z stage belt.

In particular, make sure that the Z rod bearings are all in place at the top of the bot.  Sometimes, the support nuts slip, and the bearing fall out of their cutouts.  When they fall out, they look like this:

This needs to be fixed before proceeding, as it will prevent the Z axis from moving properly.  Write-up on how to fix this issue coming soon.

Also, make sure the Z-axis platform is sitting on the four Z-axis rod guide nuts.

Power

The power switch is on the PC power supply located at the rear of the MakerBot:

Pre-Print Procedure

• Launch ReplicaotrG-0026
• There is a link to ReplicatorG on the menu bar and in the home folder. 
• Open Control Panel (the 4-arrow icon, menu Machine->Control Panel, or just Ctrl-j)
• Give the temperatures displayed in the control panel a sanity check
• Assuming the bot is cold, room temperature should be in the 20's
• Check motion of the axes to make sure everything moves correctly
• Remember that the X and Y axes move the platform the opposite direction of the arrow buttons
• CLICK THE DISABLE BUTTON to disable the steppers
• Make sure the build platform is centered in bot

Basic Print Procedure

• Obtain 3D model
• Download from Thingiverse or design your own
• Prepare 3D model
• Make sure model is STL format and is resting on the Z plane
• In ReplicatorG, open STL file
• Click on "Generate GCode" button
• Choose the SF35-CRASHbotMk6-0017 profile
• Check the "use raft" checkbox
• Select SF35-CRASHbotMk6-0017 profile and click the Generate GCode button
• After slicing, a GCode preview window will open
• You can confirm that the GCode makes sense
• Close the preview window
• Print
• Click on "Build" button 
• Watch as your object is printed out
• Finish Up 
• Open ReplicatorG Control Panel
• The part will come off the build platform more easily once it gets to 80 C
• Use the spatula to remove part
• Hit Center Y button to re-center the build platform
• CLICK THE DISABLE BUTTON to disable the steppers
• Power Down
• Close ReplicatorG
• Turn off MakerBot power supply switch

When Things Go Wrong

Lots of things can go wrong during a print.  You need to supervise the print in case something really bad happens.

• The nozzle can bury itself into the object or the build platform.
• The filament can stop extruding.
• The nozzle can stop moving while still extruding

If things go bad in a minor way, you can click on the "Stop" button in ReplicatorG.

If things go bad in a major way, you need to switch off the power switch on the MakerBot motherboard.

In either case, you need to re-open the Control Panel and reset the extruder motor speed, target temperature, and zero point.

Troubleshooting

When the MakerBot stops extruding during a print, chances are the filament has become stripped.  You will need to reverse the filament out of the Plastruder, clip it to a clean end, raise the temperature a bit, and the re-feed it into the Plastruder.  Be careful about raising the temperature of the heater.  If it gets too hot, the PTFE thermal barrier can fail, which requires rebuilding the Plasturder.  PTFE fails at about 240 C, which is not much higher than the optimal extrusion temperature.  The thermistor on the New Blankets Plastruder is not calibrated very well, and reads about 20 C hotter than it is.

If the nozzle drags into the print, check the level of the build platform and Z platform.  If they are not parallel, the nozzle can catch the build platform or object.  Spurious globs in the object can cause similar problems.

Questions, Answers(?), and Notes