Monday, March 23, 2009

Dem bones (not the song)

Yeah, just when things got interesting I broke my collarbone. Being an allweather biker for over twenty years I reckoned something like this could happen someday. That day was yesterday.
The pain is bearable, there's enough things to do to do BUT any tinkering. Which will not be possible the coming weeks...
Status 9 april, btw this is is a comminuted fracture

Saturday, March 21, 2009


The BfB kit (v2.0.1) has starshaped Z-Flanges. Material economics outweighed the construction requirements here. In my case the toothed belt realigns in continuous flip-flopping along the flange fingers and occasionally runs off from the gear.
I replaced these with full flanges cut from 5mm acrylic. With help of the FabLab and their Lasercutter. Now the belt runs much more smooth and does not roll off anymore.

Nozzle reconstruction

Took the heater barrel apart and reconstructed, now with help of the BfB tutorial video
The result is a slightly improved, not to say less worse, extrusion. Now without hand-force, it extrudes very slowly. That is no more than four odd millimeters per minute.
Think I leave the RR arest for a while until I have an idea how to improve extrusion. As the sun shines today, it's time to go out and play.

Similar report
Renoir's coach bolt solutio
Zach Hoeken's Pinchwheel Extruder prototype

Saturday, March 14, 2009

Foie gras

For some reason the current extrusion progress makes me think of force-fed geese and Pate foie gras.
Anyway, pulled the extruder apart to replace the PTFE insulator with a PEEK version. Realigned and now the extruder does extrude. Though very slow and only by hand-force helping the extruder feed :-(
So things are not allright yet. Looks very similar to the Detroit RepRap builders' experience.
Ordered a heater barrel set at BfB to give it another try.

Sunday, March 8, 2009

Throw in the towel

Spent my RR Saturday on improving the heater barrel isolation using glasswool. Then lost quite some time on figuring out why the extruder motor would not work anymore. Finally backed out to Gcode_interpreter SVN version #2483. I suspect the preparations for stepper motor extruders to be the culprit so I will leave the code in development a while for what it is.

Anyway, I tried to get the extruder to work and did not succeed. Better isolation of the barrel only slightly helped in that a little more HDPE comes out of the nozzle now. Tweaking the thermistor lookup table (with and setting Beta to 6000 :-) to achieve higher temperatures which didn't help much either. Btw, the heater shouldn't get too hot for the PTFE insulator.

I conclude I did not build the heater barrel correctly. So, I mailed BfB for a new heater barrel kit :-( and for that matter, a second extruder for future (two material) use.

Sunday, March 1, 2009

No extrusion (yet)

First extruder-test with ABS is not successful, same for HDPE. For some reason the feed stops when halfway the heater.
After cooling down, disassembled the heater and checked alignment. Due to the melted plastic no idea how to re-align again. Maybe the temperature gauged is incorrect. Heating up to 254 degrees Celsius extrudes some ten measly millimeters with the feed coming to a halt.

HydraRaptor on ABS
More ABS on HydraRaptor
RepRap thermoplast extruder testing