This is a quick and dirty high speed test print I setup today using the Bondtech dual drive extruder that @Martin_Bondeus just released. I have been testing with him for several months and it is the single best addition to my printer thus far.
The object is an 80mm cylinder printed in vase mode. I started at 6000mm/min (100mm/s) travel speed @ 0.144mm layer height. Then I ramped up the speed multiplier to 150%, then 200%, then 250% (aka 250mm/s travel). The extruder never skipped a step. The only issues with the print are from stutter at those speeds on an 8bit controller, and harmonics from my carriage due to its large 24" span and the weight.
Now for the first time I need to work on getting my printer to keep up with my extrusion capabilities… Not the other way around. missing/deleted image from Google+
I am betting that specific nozzles will need to be created for this type of printing. As the speed increases, the thermal transfer decreases due to reduced time the filament is in the hot zone. It can be combated 2 ways, increase the temperature, or increase the melt zone - So long as the nozzle stays thermally stable.
Carl and I have been talking about this. He says higher heat doesn’t help because the high speed doesn’t leave it in contact with heat long enough. A longer heat zone is really the only way after a certain point. We ran the new hotend and extruder to 250% on a cube sliced at 100 mm/sec. The infill kinda crapped out but the outside wall was fine… Except the cooling fan on the bot (not the extruder) couldn’t keep up. The cube was so hot and smushy that the corners were terrible. A different model might have done better. I don’t think a spiral case is representative of a typical print either. In any case, not all prints are created equal and some need specific slicing care. I do think as machines get faster, cooling needs will increase… And structural needs as well. I think we will see some printers show their weak points under new stresses.
Teaser: our Printrbot Pro will strive to print at speeds we have never seen before… It will use high speed servos and a special high performance all metal Ubis (longer heat zone).
I wonder what did Dynamo3D and they’re D3D printer to go at 400mm/s printing ( announced) ? They must have worked on that specific point. I couldn’t find infos about it.
The reason I ran this on an 80mm cylinder is not because it is a typical print for me. It is because circumference = π × diameter. So 80mm × 3.14 = 251.2mm. I figured it would be easy to go 1 Mississippi to confirm the travel is indeed 250mm/s.
