Sunday, June 28, 2009
Tamiya Universal Extruder
So Simon, here's your new extruder :) Actually I'll tidy up the models a bit and run you off a fresh one. The modelling has been done in BRL-CAD, exported with g-stl to STL format, then repositioned with ArtOfIllusion, saved as an STL again, converted to g-code by skeinforge and then sent to the Gcode RepRap "Phoenix" by the Java GUI program. It's a convoluted path but I kept on having snags at every darned step!
With the exception of the opto-board, all the pieces were sourced in New Zealand (which bodes well for other places). One day, I'd like to stick this on an I2C control bus so everything can be controlled from an Arduino without running out of pins!
It can take either a 16mm PTFE extruder barrel or the no-lathe heatsink one as shown. The clamp fixture is compatible with Darwin interchangeable extruder holders - I checked :) I'll post the files after their final tidying.
Wednesday, June 24, 2009
SourceForge Community Choice Awards
Voting among the finalists has started! If you'd like RepRap to win the "Project most likely to change the way we do everything" category, click on the link/image above, and - of course - tell all your friends :-)
Wednesday, June 17, 2009
We've done a video on RepRap for the finals, and we think it makes a good general introduction to the project too.
So now, when your friends who don't know the difference between the Java heap and an H bridge ask what it's all about, you can point them at that and go back to your beer...
Saturday, June 13, 2009
Acceleration Code Released
Unfortunately the new firmware is now too big to fit in the Arduino ATMEGA 168 controllers (though the old version that does is still available, of course). However, there is plenty of room in the Sanguino, and we will be supporting the Arduino Mega as a RepRap controller soon.
The new firmware buffers all movements, and so communications with the controller are now asynchronous. This completely eliminates all pauses between one movement and the next.
The main advantage of the new code is that you can run the axis motors at much lower current (as they don't have to hit the feed-rate requested in one step from a standing start) while not compromising build times; indeed, you can set higher maximum feed-rates as the machine now accelerates up to them and decelerates down.
Friday, June 12, 2009
RepRap wins at Bath University
I didn’t have to say much. When asked what was interesting about the project I said “It’s going to change the world”. She was taken aback a little, so I rammed it home: “Honest.” I said. I was then asked to summarise the work in two sentences. I looked at the ceiling for a while. “Currently we ship consumer items from the other side of the planet because we do not have the ability to make things for ourselves. The RepRap project seeks to put manufacturing power into the hands of the people by delivering a manufacturing technology which can self-replicate.”
(Poster was same from this previous post)
Sunday, June 07, 2009
Tommelise 3.0 I2C board finally built
Monday, June 01, 2009
Bowden extruder success!!
The key to this is a low-friction PTFE tube (a nod to Ian here for finding a supplier). Thanks to the archaic imperial system it is possible to get tube with an ID of 3.175 mm (1/8”) to give a nice running fit for our 3.0mm PLA filament (this is one of the few times you will witness me thanking the imperial system).
Of course hysteresis goes up as we increase the sprung length (our test used a 1 meter length to be sure). The result of this is a bit more stringy hair around the build - though Adrian’s funky acceleration code is likely to be improving matters:
Once cleaned up, we were pleased to be unable to spot the difference between builds from the first pinch-wheel extruder (back, I think) and this Bowden extruder (front, I think).
The PTFE tube can be super-glued into it’s respective housings (here ABS & PEEK) provided it is sufficiently roughed up with a file. I got my PTFE tube (1/8” ID, ¼” OD) from Adtech. I just rang Samantha there and she said if you mention the word ‘RepRap’ she might be able to sell you some without the minimum order charge.