Wednesday, February 23, 2011

Bitcoin

Bitcoin

The bitcoin project, is a an open source way of saving and transferring currency without paying fees. From the bitcoin wiki:
https://en.bitcoin.it/wiki/Main_Page

"Bitcoin is a digital currency created in 2009 by Satoshi Nakamoto.
..
It is designed around the idea of using computed solutions to mathematical problems as money, independent of any central issuing authority."

With bitcoin, reprappers could buy printed parts without paying Paypal fees and/or currency exchange fees. Reprappers could also offer printed parts for sale on a bitcoin auction site:
http://www.biddingpond.com/

without paying Ebay fees. The site is small, but you've got to start somewhere.


Dimension

Filament settings have been added to dimension. This is very loosely based on Rob Giseburt's Volumetric 5D plugin:
http://tinkerings.posterous.com/volumetric-5d

The 'Filament Diameter' should simply be set to the measured filament diameter in millimeters.

The tricky setting is the 'Filament Packing Density'. The default is 0.85, this is for ABS.

The default value is so low for ABS because ABS is relatively soft and with a pinch wheel extruder the teeth of the pinch dig in farther, so it sees a smaller effective diameter. With a hard plastic like PLA the teeth of the pinch wheel don't dig in as far, so it sees a larger effective diameter, so feeds faster, so for PLA the value should be around 0.97. This is with Wade's hobbed bolt. The effect is less significant with larger pinch wheels.

Overall, you'll have to find the optimal effective 'Filament Packing Density' by experiment.


License

The license is being changed from the GLP 3 to the more restrictive GNU Affero General Public License:
http://www.gnu.org/licenses/agpl.html

The major difference is that the GNU General Public License permits making a modified version and letting the public access it on a server without ever releasing its source code to the public.

The GNU Affero General Public License is designed specifically to ensure that, in such cases, the modified source code becomes available to the community. It requires the operator of a network server to provide the source code of the modified version running there to the users of that server. Therefore, public use of a modified version, on a publicly accessible server, gives the public access to the source code of the modified version.


Object First Layer

The first layer in raft has been changed so that now you can set the first layer infill flow rate & perimeter flow rate independently.

If your 'Object First Layer' flow rate setting is not default, you must update your 'Object First Layer' settings accordingly.


Skirt

Skirt is a script to give the extruder some extra time to begin extruding properly before beginning the object, and to put a baffle around the model in order to keep the extrusion warm.

It is loosely based on Lenbook's outline plugin:
http://www.thingiverse.com/thing:4918

it is also loosely based on the outline that Nophead sometimes uses:
http://hydraraptor.blogspot.com/2010/01/hot-metal-and-serendipity.html

and also loosely based on the baffles that Nophead made to keep corners warm:
http://hydraraptor.blogspot.com/2010/09/some-corners-like-it-hot.html

If you want only an outline, set 'Layers To' to one. This gives the extruder some extra time to begin extruding properly before beginning your object, and gives you an early verification of where your object will be extruded.

If you also want an insulating skirt around the entire object, set 'Layers To' to a huge number, like 9876554321. This will additionally make an insulating baffle around the object; to prevent moving air from cooling the object, which increases warping, especially in corners.


Thread Sequence

Fill has been changed so that the thread sequence for the first layer is now 'Perimeter > Loops > Infill'. The thread sequence for the second and higher layers is as before.

You do not need to alter any settings because of this change.


The stable cached skeinforge is the latest file at:
http://fabmetheus.crsndoo.com/

the unstable skeinforge is on my website at:
http://members.axion.net/~enrique/reprap_python_beanshell.zip

the infrequently updated subversion version is at:
https://reprap.svn.sourceforge.net/svnroot/reprap/trunk/old_files/miscellaneous/python-beanshell-scripts/