Just joined. Thanks for the feedback, Geoff - your Photogrammetry-Fu is pretty good, congrats :-) The machine you're looking at in that picture is the 12"x12"x12" prototype (T-Rex-12). So far, the tallest object we've printed on it is 10.5" - you can see it in some of the other pictures we've posted, it's that translucent vase. We have another .75" in this prototype, and the remaining .75" will be in the production machine. The longest object so far has been the Snake at a little over 13" (printed diagonally) - you can see it in the picture with 2 snakes. Let me know if you'd like me to post them here. Both were printed in PLA without any corners lifting or layer de-lamination associated with ABS. Since both of these prints achieved the state of thermal equilibrium a long time before finishing, they show that scaling them larger will work just fine. Of course, once we have the production machines up, we'll be showing that too.
Re: heated bed: so far, we've been able to print relatively large objects without it. Granted we're testing with PLA, and ABS is a whole different kettle of fish. I totally agree that for ABS you absolutely need a heated bed. So the design allows for it both mechanically (there's enough space between the glass and the aluminum plate to place a heater and an insulator, and there's space in the Z-axis housing to run the moving cable) and electrically (the controller has the power MOSFET to run it and there's plenty of power in the 24V power supply to run it on the 12" machine). In fact, I have the actual heater for the T-Rex-12 prototype sitting on my desk.
As some of the other large machine project also found out, the supply is rather thin for the heating pads of larger size. In fact, we couldn't find one for any sort of reasonable $$$. So we're looking to solve the problem our own way. I can't talk bout it yet, as we don't have the solution tested. But we are working on it, albeit at a lower priority than other tasks.
Lastly, you mention heated enclosure. I agree that a controlled thermal environment would help for some materials and some builds. The large PLA builds we've done so far don't seem to be troubled by its lack. But ABS's layer de-lamination issues can certainly be helped by it. There are two major issues with including it into the design:
1. Our machine folds - and it's a critical feature for us. We tried to include a folding enclosure, but quickly realized that doing a good job of it would delay the project by several months. We couldn't afford to do that. So we based on user feedback we decided to leave it out of this version of the machine. If enough people want it, we can work on it in the future.
2. The Stratasys patents are hanging over us in this area. The recent events show that SSYS is going to be aggressive about its patents. We simply can't afford to be involved in this fight at this time. If you think this is not the right way to approach this market, please provide this feedback to SSYS and Makerbot. They're much more likely to listen to you, the Customer, then to me.
The main reason we've not pushed hard on these two issues is that so far all the feedback we've had from the potential users is that PLA, HIPS, and Nylon are higher priority than ABS for them. So we've been told not to spend out time on this issue until later. Certainly before production machines go out the door, but not now. And we've followed that advice.
I will consider this discussion as feedback going the other way, and fold it in accordingly. Again, thank you for your feedback. Please keep it up.
Finally, we've just opened a separate forum here dedicated to our project. Please come and join us there:
http://3dprintboard.com/forumdisplay...3DMonstr-Forum
