Question for those in the know or tried it. Would the Eustathios be a good candidate for using a direct drive extruder so that ultra flexible filaments could be used or is that a bad idea on the Eustathios?
I understand that adding more mass to the moving carriage will limit speed but would other factors come into play like issues with spinning rods or rod bending on direction changes?
For trying direct drive I would suggest the flying extruder setup by @Walter_Hsiao . Another option is mounting it on the carriage directly but I might suggest going to 10mm cross rods to help fight deflection across the span.
I will love to see what you come up with. That’s one of the main reasons the open source design of this printer is so much fun. Because people make so many cool upgrades and modifications since the files are there for you to hack and do with what you see fit.
I modified one of @Eclsnowman s older designs for the chimera hotend resulting in a bulky hybrid direct/bowden carriage. One hotend ist feeded by a E3D titan extruder while the second hotend works as a bowden hotend. After switching from the original dual bowden hotend the only disadvantage i noticed was a slightly stronger ringing due to the increased mass. My motivation was to be able to print flexible filaments and soluble support filaments. The results with flexible TPU filament are satisfactory (50mm/s works good).
I have a custom coreXY that I use with the Modicum extruder and I have no issues printing flexible filaments with a 90A shore hardness (Semiflex, SainSmart TPU). I use 30mm/s and no retraction and don’t get many strings. It prints very well.