MakerBot Note :

[shamefully ripped from mailing list, I'm keeping it here for my personal reference]

Put a "tail" at the beginning of your print. I never print without a
tail, even if I have a raft. Basically at the beginning of your gcode
around the point where your print starts change your gcode from this

G1 X-31.05 Y-39.88 Z0.44 F3300.0
G1 X-31.05 Y39.74 Z0.44 F940.828
G1 X-30.93 Y39.86 Z0.44 F940.828
G1 X-29.64 Y39.86 Z0.44 F940.828

to something along the lines of this

G1 X-48 Y48 Z0.44 F3300.0
G1 X-48 Y-48 Z0.44 F945
G1 X48 Y-48 Z0.44 F945
G1 X48 Y48 Z0.44 F945
G1 X-48 Y48 Z0.44 F945
G1 (the code for your 1st layer)

What causes lack of sticking t is two fold. 1st the plastic in the
tip of your nozzle is not 230-240, it's more like 200-210, it's really
not sticky. The extruded plastic isn't up to temp till you have
extruded 1-2cm. The tail gets the extruded plastic solidly up to temp
before you print your interface layer.

Second when printing raft less your Z needs to be very squished into
the plate, the tail gives you 10-20 seconds to jog you z axis to the
perfect level. And it lets you find any imperfections in your
leveling before you loose the print.

MakerBot Note :

If you haven't specially calibrated your thermistor settings, you might have to tweak the temperature settings in skeinforge to get the plastic soft enough. In my machine, the extruder jams for all temperatures lower than 230C. So, I had to go deep into the skeinforge-raft settings and make sure _all_ extrusion temperatures are above 230C.

warning : 230C may be more than enough to melt your insulator barrel if you are using the white PTFE part that ships with the kit. I bought a PEEK barrel from MakerGear and am currently praying to various gods that it does not suffer the same sort of failure at my PTFE barrel.

MakerBot Note :

The M6 pre-assembled heater-core from MakerGear simplifies building the hot part of the plastic extruder.

MakerBot Note :

When affixing the MK4 idler pulley to its bearing, try to center it. The washer-spacing method in the default instructions did not centre my pulley. It seems to grip filament more reliably if properly centered, and then mounted with a single washer spacer on each side.

MakerBot Note :

Always add a copper sleeve or hose clamp around your heater insulator barrel. This will save you if you accidentally run to hot and start to deform the insulator.

MakerBot Note :

If your filament has a "skirt" around it, or multiple threads, when you back it out of the heater, it means that your seal between the insulator and barrel is failing and you need to shore up the strength of your insulator barrel and probably reduce your temperature, and check for nozzle obstructions.

MakerBot Note :

The MK5 extruder idler pulley wheel does not work with the MK4 extruder gear

MakerBot Note :

Put a 'flag' of masking tape on your extruder feed 2mm calibration rod. If you are debugging feed problems and need to repeatedly remove your motor for cleaning, you will probably and up trying to calibrate the feed mechanism with the heater element attached. And, if you are clumsy like me, you will probably end up dropping the calibration rod into the heating element.

MakerBot Note :

Let the machine warm up for 10 minutes before turning on the feed. The thermistor only reports the temperature at the tip of the extruder. Give the machine a while for this heat to diffuse along the barrel


Preparing .PDB Files for 3D Printing

I would like to print some files from the swiss protein databank into nice 3D surface models. This can be done on linux with standard open software packages.
  • assume platform is Ubutntu
  • assume that you have Replicatorg set up with Skeinforge and some sort of RepRap style 3D printer.
  • install meshlab
  • install blender
  • download .pdb
  • open .pdb in meshlab. Use the metaballs setting with resolution = 0.5 and blobbiness = 0.5
  • optionally clean up mesh
  • center and scale in blender
  • orient model in a way that looks mostly printable
  • export model as .STL
  • open model in replicatorg-skeinforge

Follow-up : Although this will create manifold meshes that skeinforge can process, it doesn't create support structures and other niceties requires for Makerbot / RepRap printing. Ideas ?
  • try out the skeinforge support settings
  • manually add support columns in Blender
  • write a script to automatically create supports (hard, don't know what algorithm to use)


Unboxing Maker-Bot revision 10 (11?)

Yes! it finally arrived!
With a very nice greeting
I ordered the basic $750 kit,
but added on the power supply, the USB-TTY cable,
and two extra reels of ABS.
Start assembly with the Y stage
Then build the X stage and attach the two
You know what, these are the same pics you can see at wiki.makerbot.com/cupcake, I'm not gonna write.

Thing 1 from thingiverse is printed !

Printing its own replacement parts !