Some filaments contract too much and warp the extruded object.  To prevent this you have to print the object in a temperature regulated chamber and/or on a temperature regulated bed. The chamber tool allows you to control the bed and chamber temperature and the holding pressure.
 
The chamber gcodes are also described at:
 
http://reprap.org/wiki/Mendel_User_Manual:_RepRapGCodes
 
The chamber manual page is at:
 
http://fabmetheus.crsndoo.com/wiki/index.php/Skeinforge_Chamber
 
Operation
Settings
  Bed
    Bed Temperature
    Bed Temperature Begin Change Height
    Bed Temperature End Change Height
    Bed Temperature End
  Chamber Temperature
  Holding Force
Heated Beds
  Bothacker
  Domingo
  Jmil
  Metalab
  Nophead
  Prusajr
  Zaggo
Examples
Operation
The default 'Activate Chamber' checkbox is on.  When it is on, the functions described below will work, when it is off, nothing will be done.
 
Settings
Bed
The initial bed temperature is defined by 'Bed Temperature'.  If the 'Bed Temperature End Change Height' is greater or equal to the 'Bed Temperature Begin Change Height' and the 'Bed Temperature Begin Change Height' is greater or equal to zero, then the temperature will be ramped toward the 'Bed Temperature End'.  The ramp will start once the extruder reaches the 'Bed Temperature Begin Change Height', then the bed temperature will approach the 'Bed Temperature End' as the extruder reaches the 'Bed Temperature End Change Height', finally the bed temperature will stay at the 'Bed Temperature End' for the remainder of the build.
 
The idea is described at:
http://www.makerbot.com/blog/2011/03/17/if-you-cant-stand-the-heat/
 
Bed Temperature
Default: 60C
 
Defines the initial print bed temperature in Celcius by adding an M140 command.
 
Bed Temperature Begin Change Height
Default: -1 mm
 
Defines the height of the beginning of the temperature ramp.  If the 'Bed Temperature End Change Height' is less than zero, the bed temperature will remain at the initial 'Bed Temperature'.
 
Bed Temperature End Change Height
Default: -1 mm
 
Defines the height of the end of the temperature ramp.  If the 'Bed Temperature End Change Height' is less than zero or less than the 'Bed Temperature Begin Change Height', the bed temperature will remain at the initial 'Bed Temperature'.
 
Bed Temperature End
Default: 20C
 
Defines the end bed temperature if there is a temperature ramp.
 
Chamber Temperature
Default: 30C
 
Defines the chamber temperature in Celcius by adding an M141 command.
 
Holding Force
Default: 0
 
Defines the holding pressure of a mechanism, like a vacuum table or electromagnet, to hold the bed surface or object, by adding an M142 command.  The holding pressure is in bars. For hardware which only has on/off holding, when the holding pressure is zero, turn off holding, when the holding pressure is greater than zero, turn on holding. 
 
Heated Beds
Bothacker
A resistor heated aluminum plate by Bothacker:
 
http://bothacker.com
 
with an article at:
 
http://bothacker.com/2009/12/18/heated-build-platform/
 
Domingo
A heated copper build plate by Domingo:
 
http://casainho-emcrepstrap.blogspot.com/
 
with articles at:
 
http://casainho-emcrepstrap.blogspot.com/2010/01/first-time-with-pla-testing-it-also-on.html
 
http://casainho-emcrepstrap.blogspot.com/2010/01/call-for-helpideas-to-develop-heated.html
 
http://casainho-emcrepstrap.blogspot.com/2010/01/new-heated-build-platform.html
 
http://casainho-emcrepstrap.blogspot.com/2010/01/no-acrylic-and-instead-kapton-tape-on.html
 
http://casainho-emcrepstrap.blogspot.com/2010/01/problems-with-heated-build-platform-and.html
 
http://casainho-emcrepstrap.blogspot.com/2010/01/perfect-build-platform.html
 
http://casainho-emcrepstrap.blogspot.com/2009/12/almost-no-warp.html
 
http://casainho-emcrepstrap.blogspot.com/2009/12/heated-base-plate.html
 
Jmil
A heated build stage by jmil, over at:
 
http://www.hive76.org
 
with articles at:
 
http://www.hive76.org/handling-hot-build-surfaces
 
http://www.hive76.org/heated-build-stage-success
 
Metalab
A heated base by the Metalab folks:
 
http://reprap.soup.io
 
with information at:
 
http://reprap.soup.io/?search=heated%20base
 
Nophead
A resistor heated aluminum bed by Nophead:
 
http://hydraraptor.blogspot.com
 
with articles at:
 
http://hydraraptor.blogspot.com/2010/01/will-it-stick.html
 
http://hydraraptor.blogspot.com/2010/01/hot-metal-and-serendipity.html
 
http://hydraraptor.blogspot.com/2010/01/new-year-new-plastic.html
 
http://hydraraptor.blogspot.com/2010/01/hot-bed.html
 
Prusajr
A resistive wire heated plexiglass plate by prusajr:
 
http://prusadjs.cz/
 
with articles at:
 
http://prusadjs.cz/2010/01/heated-reprap-print-bed-mk2/
 
http://prusadjs.cz/2009/11/look-ma-no-warping-heated-reprap-print-bed/
 
Zaggo
A resistor heated aluminum plate by Zaggo at Pleasant Software:
 
http://pleasantsoftware.com/developer/3d/
 
with articles at:
 
http://pleasantsoftware.com/developer/3d/2009/12/05/raftless/
 
http://pleasantsoftware.com/developer/3d/2009/11/15/living-in-times-of-warp-free-printing/
 
http://pleasantsoftware.com/developer/3d/2009/11/12/canned-heat/
 
Examples
The following examples chamber the file Screw Holder Bottom.stl.  The examples are run in a terminal in the folder which contains Screw Holder Bottom.stl and chamber.py.
 
> python chamber.py
This brings up the chamber dialog.
 
> python chamber.py Screw Holder Bottom.stl
The chamber tool is parsing the file:
Screw Holder Bottom.stl
..
The chamber tool has created the file:
Screw Holder Bottom_chamber.gcode
| Classes | ||||||||||||||||||
| 
 
 
 
 | ||||||||||||||||||
| Functions | ||
| 
 
 
 
 
 | ||
| Data | ||
| __author__ = 'Enrique Perez (perez_enrique@yahoo.com)' __date__ = '$Date: 2008/21/04 $' __license__ = 'GNU Affero General Public License http://www.gnu.org/licenses/agpl.html' absolute_import = _Feature((2, 5, 0, 'alpha', 1), (2, 7, 0, 'alpha', 0), 16384) | ||
| Author | ||
| Enrique Perez (perez_enrique@yahoo.com) | ||