Reasons Parts Fail (MakerBot)

There are a variety of reasons why a part may fail on the MakerBot. It is important to monitor the print regularly in order to catch potential failure. This page will list a few reasons why a part might fail and how the problem can be resolved.
==Extrusion Stops==
===Tangled Filament===
One of the most common causes of a failed print is stuck filament. When the filament gets stuck, the extruder no longer has any material to work with, and will continue on printing nothing. It is hard to catch this before it happens without sitting and watching the entire print (which is a waste of time). If this happens, stop the print and ensure the filament is feeding in such that it will not catch on anything when you attempt the print again.
===Clogged Nozzle===
A clogged nozzle will make the printer unable to extrude more plastic. To check if the nozzle is clogged, go to the LCD menu and run the Load script in Utilities > Change Filament. If the plastic curls up toward the extruded, the nozzle is probably clogged and needs to be unclogged.
If the nozzle is clogged, you should probably ask a mentor to help you fix the issue, but here are the steps you can take to fix it.
# Unload filament from extruder.
# Turn off the MakerBot.
# Loosen the two bolts on the front of the extruder, unplug the motor, and pull the motor out.
# Turn on the Makerbot and heat the nozzle by running preheat or load filament script.
# When the nozzle is hot enough, take some filament and push it through the tube manually.
# When the filament begins to extrude, pull it out and cut the end off.
# Repeat ~3-4 times until the nozzle seems unclogged.
# Cancel the script that is heating the nozzle, let the nozzle cool, and shut off the MakerBot.
# Reassemble the extruder and start the MakerBot up again.
# Test. If the extruder works normally, you're done!
If this process doesn't work, wait until a mentor can come help you fix the problem.	
==Extrusion Stops==
===Tangled Filament===
One of the most common causes of a failed print is stuck filament. When the filament gets stuck, the extruder no longer has any material to work with, and will continue on printing nothing. It is hard to catch this before it happens without sitting and watching the entire print (which is a waste of time). If this happens, stop the print and ensure the filament is feeding in such that it will not catch on anything when you attempt the print again.
===Clogged Nozzle===
A clogged nozzle will make the printer unable to extrude more plastic. To check if the nozzle is clogged, go to the LCD menu and run the Load script in Utilities > Change Filament. If the plastic curls up toward the extruded, the nozzle is probably clogged and needs to be unclogged.
If the nozzle is clogged, you should probably ask a mentor to help you fix the issue, but here are the steps you can take to fix it.
# Unload filament from extruder.
# Turn off the MakerBot.
# Loosen the two bolts on the front of the extruder, unplug the motor, and pull the motor out.
# Turn on the Makerbot and heat the nozzle by running preheat or load filament script.
# When the nozzle is hot enough, take some filament and push it through the tube manually.
# When the filament begins to extrude, pull it out and cut the end off.
# Repeat ~3-4 times until the nozzle seems unclogged.
# Cancel the script that is heating the nozzle, let the nozzle cool, and shut off the MakerBot.
# Reassemble the extruder and start the MakerBot up again.
# Test. If the extruder works normally, you're done!
If this process doesn't work, wait until a mentor can come help you fix the problem.
==No Supports or Incorrect Supports==
==Print Not Sticking to Build Plate==
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A print can fail if the base does not adhere properly to the base plate. There are a few things that can cause this: 
# The base plate is not level. It could be possible that the base plate is not level. If the base plate isn't level your part may come out lopsided or won't stick properly. See Leveling Base Tray for instructions on how to level the base plate.
# Bubbles or Other Defects in Tape There is tape on the base plate in order to make maintaining the MakerBot easier. If there are any defects in the surface such as bubbles or significant wear, the part will have trouble sticking. See Maintaining Tape for more information.
# Complex Geometry Complex geometry on the bottom side of a part can cause issues with adhering to the base plate. Try simplifying the part geometry or adding a raft to avoid this issue. 
==References==
http://download.makerbot.com/replicator/MB_Replicator_UserManual.pdf
https://support.makerbot.com/learn/makerbot-replicator-2/extruder/how-to-unclog-a-nozzle_13470