Lulzbot knows where they want to take the Taz. I know where I want to take the Taz. They aren’t always in the same direction. Either way, I think there is still room in the Taz design for innovation in the future. The ability to print at large size is a definite design advantage, one I think more people will take advantage of as time goes by, and something that prevents the Ultimaker from being a direct competitor for the entire market share.
The X carriage is something that I have been giving a lot of thought. I do not feel that Bowden type extruder setups are a viable answer. They struggle with too many different materials. Direct Drive (Mk 8, Bondtech, etc.) might be a viable replacement for the Wade style extruders, getting the torque and longevity to match is going to be difficult. I haven’t met an extruder with the tractor force of a wade extruder when dealing with a full 6lb roll of plastic except for possibly the Bondtech extruder, which has a few other quirks. I like the idea of a belted replacement, which could be made smaller, and I am playing with a clockwork style nested extruder (short shaft hollow 11mm Nema 17 motor shaft with a solid long 5mm shaft NEMA 17 motor behind it coaxially, with a matching set of extruder mechanics) to see if that can reduce the dual extruder footprint, but there is only so small we can make the package with NEMA 17 base motors. Torque tube designs are also feasible, but tend to have lag at the far end on start and stop.
I suspect in the long run, we’ll see a pellet style hybrid polyjet style head printing ABS plastic through jets through a heated block, using air to deposit material instead of torque, with the larger feed filament reserved for main fill material. We are years away from the necessary patents for that technique expiring though, and even then, scaling it up for molten plastic will not be easy.
With the existing Taz print head though, there is room for making it more compact. Just going with a belt would allow the entire package to fit between the edge of the hotend barrel and the edge of the NEMA 17 motor. Converting the base to something incorporating some of the features of the Tornado extruder, particularly the integral ducting http://www.thingiverse.com/thing:1246951 might be worth looking at. There is also opportunity to use mill max spring contact pins for the extruder power and data feeds.
What I eventually envision for my ideal Taz style X axis is this:
a single 20mm x 40mm extrusion carrying a pair of low profile NEMA 17 motors, coaxially located, feeding via belt to a pair of bondtech extruder cores also coaxially aligned. The entire package rides on a small aluminum carriage, and seats into a deep V groove with two spring based retaining clips capable of supplying sufficient force to prevent any extrusion movement. Data and power ports would be located on the bottom of the assembly. A smaller single head extruder could be swapped in the same location to save on cost or weight. A carriage position magnetic encoder would be located on the back carriage, and the entire assembly would be 1/2 the weight of the existing carriage, including the fans. A filament break or jam sensor, with optional filament re-feed motor would be located at the frame.
I don’t know if it is feasible or smart to go that route yet, but that is what I plan to attempt.
Overall I would say we have a better community here, though recently the population is in decline. I think part of that is because I haven’t been posting as many new, relevant designs, but there is also less of a chance for people posting here to actually interact with Lulzbot staff and exchange ideas, etc. They are a big company now, it’s hard to break away from that to interact on message boards, especially where half the time its angry annoyed people anyways, but I still miss the community interaction. And it has been going back up some, so there is that.
Ultimaker has been probably more active about incorporating user designed features in their printers than Lulzbot. The “Olsen Block” for example. Ironically, we actually have a much bigger printer modification pool over here.
I dunno where I was going with all of that. I guess the rate of innovation is largely based off what is easy sustain. For a lot of that it means funding parts and having ideas in the first place. My printing and filament costs are largely self sufficient to support itself as a hobby, which is rare, but its difficult to fund chancy upgrades that only have 50% odds of working continually without dropping off one of the other hobbies. It’s rare to see as many different upgrade designers out there as this community has, who have sustained designing over a relatively long period of time.
If you look in Devel.lulzbot.com they are continually working on new products and ideas as well still. though I don’t seem to notice as many pure research projects as before. Part of that is definitely due to the increase in software side involvement, (CURA, etc.)