3d printing has come huge strides in ability to construct detailed objects. Unfortunately, color is still a considerable limitation. Here, some people at the Reprap blog are having fun coming up with an extruder head that actually mixes two colors as it deposits them. Don’t confuse this with the dual head that Makerbot is touting that allows you to switch colors on the fly, this is a single head that actually has a cavity where the material is melted, then stirred to create a combination of the two. It is an interesting method of overcoming a limited supply of colors.
Having this extra stirring chamber means that there would be a small amount of material wasted any time that you wanted to make a change to the color, as it would have to be purged. There are some interesting thoughts in their comments on how to use this extra material most efficiently.
OMG! CMYK RepRaps FTW! :-)
CMYKV actually (Cyan, Magenta, Yellow, Key, Virgin for the uninformed)
That’s very interesting but I can’t help but look at those printed parts and ask why they aren’t calibrating their printer. Those parts just look fugly and give more fuel to the fire for those who like to give RepRaps and their derivatives a bad rap.
Srsly. I don’t understand the excitement over extruders when there are superior technologies.
Superior technologies such as?
That is such a trolling statement, I won’t even go where that could lead.
My response to such a blanket statement of “superior” or “best” is that “It’s all relative”. Best all depends on the situation and can based on; intro cost, cost per unit, time, ease of use, experience needed, intended use, plus so many other variables.
One might say that Ferrari is the best car, but it wouldn’t make a good furniture hauler….
Yes, there are “better” technologies available. That cost orders of magnitude more for entry.
first I’ve never seen or heard of this bad rap that you mention is this part of the makerbot pretends reprap doesn’t exist myth?
second its a prototype of course they are not going to spend endless hours getting top resolution that’s not the point here they just want different colors they probably took a picture and posted it as soon as they got some results
third some people like the character of a low-res but functional “ugly” print it will be a sad day when every one is obsessed with getting perfect smooth finishes
The printer could buffer the incoming instructions and switch colors early so it wouldn’t waste any plastic.
The problem is that it wont change colours abruptly (for a lack of a better term). Think of it as having a glass of chocolate milk, now add milk until it all turns white, it’ll take a while.
Smart slicing software could handle that in some cases. If it is going to be doing infill that is never seen and a color change is coming up, it could start mixing the new color and just extrude the old-becoming-new mix.
However, since I believe the filament change is still a manual process for this extruder, you are never going to have the problem you describe.
@sneakypoo: seconded.
It’s quite pretty when an industrial extruder does a colour change. you get a ~60cm stalagmite of colour-gradient plastic :)
The algorithm for this would be extremely nontrivial, but if the colors changes are kept to a minimum head travel could be changed to where color change overage is deposited as supports or fills.
I also like the secondary object idea, it sounds fun to make piles of odd variegated things with the overage.
it would definitely drop the price of reprap parts if the default for color purging was to print prusa components