Tuesday, May 22, 2007
PLA Darwin part
By raising the extrusion temperature to 165C I've managed to get PLA going through without blowing up the extruder motor - earlier attempts tightened the clamp too much and overloaded the poor little motor (may it rest in peace). PLA strings more than CAPA, but is significantly more rigid. Here is a Darwin bed clamp that I printed off on Zaphod last night:
The holes have since been cleared of stringing with a penknife. I'll try some more complex Darwin parts later, but there are some modifications needed to the code to conserve memory for large or complex builds.
I've also got to fit the modified extruder drive - the one with a flexible shaft. Hopefully this will let the rigid PLA filament feed more freely still.
Vik :v)
The holes have since been cleared of stringing with a penknife. I'll try some more complex Darwin parts later, but there are some modifications needed to the code to conserve memory for large or complex builds.
I've also got to fit the modified extruder drive - the one with a flexible shaft. Hopefully this will let the rigid PLA filament feed more freely still.
Vik :v)
Labels: bed, clamp, pla, zaphod
Sunday, May 13, 2007
PLA Filament works
Back at the start of the year, plastics suppliers Claraint were kind enough to donate 10kg of polylactic acid (PLA) granules to the RepRap Project. Alan from Imagin Plastics - a welding rod and extrusion specialist in Henderson, New Zealand - then ran these granules through an extruder to produce 800m of 3mm diameter filament which I picked up on Friday. It was dried overnight at 60C and then extruded using a 180C die and 170C feed. Here's there wondrous extrusion machine:
And here's the batch of filament I picked up. It's actually quite transparent.
By running an unmodified Mk2 extruder at 155C and increasing the pressure on the filament - it's much harder than CAPA - I managed to run it well enough to produce this shotglass:
This material definitiely has some artistic possibilities.
Further experimentation is needed, but it does look like it will be possible to make watertight containers with a reasonable degree of strength from PLA in a Darwin. A straight-through extruder would probably have an easier time feeding filament, as the stuff is rather stiff.
Vik :v)
And here's the batch of filament I picked up. It's actually quite transparent.
By running an unmodified Mk2 extruder at 155C and increasing the pressure on the filament - it's much harder than CAPA - I managed to run it well enough to produce this shotglass:
This material definitiely has some artistic possibilities.
Further experimentation is needed, but it does look like it will be possible to make watertight containers with a reasonable degree of strength from PLA in a Darwin. A straight-through extruder would probably have an easier time feeding filament, as the stuff is rather stiff.
Vik :v)
Labels: clariant, extrusion, filament, henderson, imagin plastics, pla, polylactic acid, reprap, zaphod
Tuesday, March 27, 2007
Untimely Lapse Movie
I've had a go at printing one of Ed's Darwin corner brackets. On about the 5th layer, the output detached itself from the stage and got pushed around a bit. While this wasn't exactly a huge success, it does look very much like we're on the right track so I've been persuaded to post the video. As per the last one, there are approximately 2.5 seconds between each frame.
Right at the end you can see the deposited part start to detach and go springy before it gets pushed around. You can also see the second head appearing in the right of the frame in the latter half of the movie. The camera moves around a little as the USB lead was dragging on things, but I fixed that with some tape about half way through; not a problem as it actually gave a better camera angle!
Adhesion to the stage (or lack thereof) is my big bugbear, and I'm going to try a light coat of varnish as previous tests have shown molten CAPA sticks to it like glue. If that doesn't work, I'm onto foam bases like the rest of 'em.
Vik :v)
Right at the end you can see the deposited part start to detach and go springy before it gets pushed around. You can also see the second head appearing in the right of the frame in the latter half of the movie. The camera moves around a little as the USB lead was dragging on things, but I fixed that with some tape about half way through; not a problem as it actually gave a better camera angle!
Adhesion to the stage (or lack thereof) is my big bugbear, and I'm going to try a light coat of varnish as previous tests have shown molten CAPA sticks to it like glue. If that doesn't work, I'm onto foam bases like the rest of 'em.
Vik :v)
Labels: bracket, capa, darwin, detached, fails, reprap, stage, zaphod
Sunday, March 25, 2007
Time-lapse video of test hexagon.
A few people have asked me if I would make a short time-lapse movie of something being RepRapped. So, thank you for the inspiration. I finally got round to it on the second attempt, after earlier borrowing a higher quality camera that unfortunately lacked macro focus:
The object is a standard 20mm (approx) test hexagon, 5mm (quite accurate) thick, extruded from CAPA. There are approximately 2.5 seconds per frame. I used a Linux script of my own devising and a Logitech 320x240 webcam clamped to the base board, which I will document and GPL if anyone is interested. Donations of higher quality equipment greatfully accepted!
Here's what that lot looks like:
Vik :v)
The object is a standard 20mm (approx) test hexagon, 5mm (quite accurate) thick, extruded from CAPA. There are approximately 2.5 seconds per frame. I used a Linux script of my own devising and a Logitech 320x240 webcam clamped to the base board, which I will document and GPL if anyone is interested. Donations of higher quality equipment greatfully accepted!
Here's what that lot looks like:
Vik :v)
Labels: capa, extrusion, fast, hexagon, polymorph, reprap, sped up, test, time lapse, video, zaphod
Tuesday, March 06, 2007
The Extruded Extruder Extrudes!
I tidied up the bearings and rammed a pin through the top of the screw thread to join it to the coupler. It now extrudes! Yay! Can't say for how long because it's strong enough to split the nozzle, or at least blow out the weak parts on it. Closer inspection shows where I cut things just a little too fine drilling the nozzle out, and a bit of soldering is required to patch it.
The extruded extruder is the one with the red light on. The black thing on the board is just to allow a bit of contrast so you can see the extruded stuff. I've used an ABS clamp off the Stratasys to hold the PTFE part of the nozzle, but I aim to replace that when the software is running happily again.
Zaphod now has two heads.
Vik :v)
The extruded extruder is the one with the red light on. The black thing on the board is just to allow a bit of contrast so you can see the extruded stuff. I've used an ABS clamp off the Stratasys to hold the PTFE part of the nozzle, but I aim to replace that when the software is running happily again.
Zaphod now has two heads.
Vik :v)
Labels: capa, extruded, extruder, reprap, zaphod
