I'm happy to report that Makerbot 866 is alive!
I was able to get the plastruder put together fairly easily. I used a PEEK insulator and pre-made heat core from MakerGear that reduced and amount of effort I needed to do.
I then hooked it up and tried the manual control. I was able to move right and left (x-axis) and up and down (z-axis), but wasn't able to move back and forth (y-axis). I also heated up the extruder barrel. After waiting for it to reach 220 degrees Celsius, I turned on the extruder motor and after a few seconds, a thin plastic strip came out! Overall I was very happy, I just needed to get the y-axis working.
Next I took off the x/y assembly, but left it wired up to the control panel. I then tested the y-axis again, and now that it was out of the machine it worked. I guessed that the bolt holding the y-pulley was rubbing against the rods for the x-axis since several other people had complained about it with their machines. I cut the bolt using a dremel so that is would stay above the x-rod and reassembled the machine. Now everything worked!
A made a cube, 1cm on a side, using OpenSCAD and used Skeinforge to convert the STL file to gcode for the machine, just using the default settings for everything. It took several attempts to figure out the best way to position the head to start. The machine first builds a raft consisting of a layer of horizontal lines followed by a layer of vertical lines, followed by the layers of the object being build. The idea of the raft is to give a stable base to build the rest of the object. I was having trouble of the raft not sticking to the build platform the then the head would push it around making what looked like a pile of spaghetti. I found out by raising the temperature a little bit and putting the head very close to the platform, I was able to get a good enough raft to build the cube.
Here is the underside of the raft. You can see on the right side that it didn't start sticking right away, but it was good enough to make the cube.
Here is the cube before I cleaned it up. You can see the raft on the bottom and a hanging thread on the top. (Click on any picture to enlarge.)
I measured the resulting cube, and it was very accurate to 1 cm. I counted about 30 layers on the cube, so the vertical resolution is around .3 mm.
Next I downloaded some g-code to make a crank, but it didn't turn out very well as it looked very blobby. I'm guessing that it was sliced up using different parameters than I used, so I might try downloading the original STL file and running Skeinforge on it myself.
Digital Fabrication >