Robo3d R1 E3D Flex Filament Guide by valkary007

Last crawled date: 3 years ago

April 14, 2017 Update: Apparently, the R1+ has a different feeder geometry, so it does not fit the R1+. R1 is still all good though :-).June 21, 2016 Update: A few users have had problems and we're trying to figure out if its the dimensional accuracy of the printed part or if its something less fundamental. I'm going to get back to printing with flex and i'm sure the part will be updated.Nov 22, 2015 Update: A user has successfully used this part using PETG with the stock hexagon hot end. They couldn't print with PETG previously without the material bunching up under the hot end. Keep the posts coming!Nov 15, 2015 Update: By popular demand (2 requests in comments), I've added a variant where the PTFE flare is removed. Anyone with a robo3D should be able to use this, but I need the community to test it. I would first try it with regular filament, to make sure the hobbed bolt and bearing still push the filament as efficiently, and then try with Flex. Try slow speeds at first (10mm/sec?). Thanks!
Video Here: https://youtu.be/5TzSODHT6Zk 215 Degrees, 15mm/sec, Filaflex, 110% extrusion, 0.1mm layer height, 0.3mm nozzle.
I have a Robo3d R1 with an E3D Hot end and I've found that flex material (NinjaFlex, FilaFlex) does not print reliably, if at all. When installing the E3D hot end, it is suggested to drill out the 'filament hole' beneath the hobbed bolt so the PTFE tube can be cut just under the bolt. While this worked OK, I had reliability issues.
The problem is that printing with Flex is like pushing a rope: it simply buckles in the transverse direction rather than applying force axially. If the rope is constrained in a tube, then as long as the axial force is higher than the friction of the ''rope' against the tube, it will slide through it.
I made a part that fills in the gaps between the hobbed bolt, bearing, and 'tube' so when the flex filament is pushed, it can't box-car and buckle. This part is the result of many iterations and now I'm finally at a design that is reliable.
Instructions:
1) Get a Robo3D, install the E3D hot end, and drill out the filament hole. This will allow the PTFE tube to extend from the hobbed bolt all the way down to the hot end.
2) Print this part with its large flat face down on the bed.
3) Install: cut back the PTFE tube so it sits in the small half-moon feature when this part is installed.
4) Enjoy printing with flex. I Print with Filaflex : 215 degrees, 20mm/sec, 110% extrustion.
These settings are fine with Ninjaflex as well.
I've found that this part can be left in the extruder assembly and material can be changed out as usual: compressing the springs, yanking the old material out, inserting the new material and turning the gear.
If there is interest, I can modify this part to be used with a non-E3D hot end, but someone else will need to test it. I'd just make a channel where the PTFE tube is, which wil guide the filament into the stock filament hole under the bolt.