After connecting Johns Arduino I proceeded to try printing the large Yoda I had fail time and time again using my 1280 and Marlin. To my surprise it made it far past the point at which it had been failing when I realized I did not have enough filament to finish. Expecting to have a communication error and not wanting to waste new filament I started inserting short lengths of various PLA I had lying around into the extruder one after another. The result was a large rainbow yoda.
The results were far better than I was expecting for such an early print and very little calibration. I am attributing this to the quality of code being produced by Slic3r and the look-a-head in marlin.
It was now time to see how fast I could go without losing quality. I used Le_garages Grotux and printed it with four perimeters and various speeds until I found the sweet spot of between 80 and 125mm/s for print moves.
I quickly found the need for a fan so I designed a simple fan mount to hold a 40mm fan to the side of the machine. Here it is printing at 80mm/s perimeter with 200mm/s travel speed. It has a bit of ooze still at this point in the tuning.
As you can see from the following picture it is almost impossible to print small parts at these speeds without a fan or cooling (first one). The second one is with the fan added. The third and fourth are the combined results of the fan and Slic3rs brand new cool feature.
I also decided to try and tune the advance feature in Marlin with very poor results. The picture shows the average result whenever the advance K is set enough to deal with the hysteresis. (edit: these were done at 200mm/s)
Instead of wasting plastic printing more cubes or toys to tune the retract and acceleration I decided to use Prusa parts.
So far the results are far exceeding my expectations and I will be moving on to the Beta testing stage now with John Biehler being the first to print the Beta 0.1 in ABS on his Thing-o-matic.