@Jason_McMullan ok, here’s a crazy idea, what if you added an airflow fan and vent or something to cool the retracting filament, solidify the stringy bit, and cause it to break shorter? I’m imagining a blower fan or aquarium pump pushing air into a series of small holes placed below the Y block.
@Ryan_Carlyle Slow retraction (to form a small ‘tip’), followed by fast retraction seems to be the key to success for me with PLA.
I just finished a ‘traffic cone’ print (with two filament swaps per layer) with no jams using this technique.
Said successful “hands off” traffic cone print.
The careful observer will note that I had to hot splice in the blue, as I realized I was going to run out of gray after depositing the brim.
After that, however, the rest was untouched.missing/deleted image from Google+
May i suggest brass inserts for the bowden couplers?
Nice work! Are you posting gcode and files? I wanna play!
@kenneth_rooks good idea - I’ll see if I can source some.
@Ross_Hendrickson My design is based off of what I saw for the Prometheus System, but adapted for PTFE lined hotends like the E3Dv6 Lite.
For an all-metal hotend like the Prometheus, you will probably need a PEEK liner such as their system.
I’ve found a better model on Thingiverse:
yeah, I have an E3Dv6 lite so, I’m of course very interested :). What kind of extruder/hobbed bolt are you using?
@Ross_Hendrickson Geeetech MK8 long reach Bowden
Impressive. I would suggest a transition tower though.
Sory article only in italian but hope paramerer can help you on setting (4 way mix from 2014)
@Mauro_Manco its very interesting article - reading the gcode, it appears that he uses a “dump bin” at 0,0,0 instead of a purge tower.
Still dumps 60mm per filament change, but only has to do that on filament change layers, instead of printing a purge layer every layer.
I’m with @Ryan_Carlyle here that a ram purge is almost certain to eliminate the whisker. I realise it has a whole raft of caveats with needing a dump area or object. But because you’re eliminating all fluid polymer there can be nothing left to string.
Do also consider that because ram-purging truly removes the filament left in the nozzle leaving it almost completely clean that you may find that you just much crisper cleaner colour changes too. Perhaps even enough so that you can do things like support materials.
I really need to write a blog post on ram-purging and the details of how and why it works, as well as how to implement it. It’s very much a per-system, per material thing that you need to tweak, but it’s very cool and very effective.
@Sanjay_Mortimer1 I would love to read more details about ram purging!
I have bondtech extruders to Bowden setup and I am using the Artemis Dual 2 into 1 Y and adapted to a water cooled xrc single and an e3d copper hotend with high temp heater. Intent is to print 2 to 1 high temp for one line being matterhacker nylonX carbon fiber and the other pro series nylon. Printing at 270 for the nylonX and 248 for the pro nylon. Have had some issues with whiskers too. I am going a little different rout. I design an inline filament cutter that I am going to install between the Y and hot end. This will make a clean cut just prior the retraction, no more whiskers. Just finished the design and should have it put together in the next couple weeks. I modified marlin single nozzle adding the servo from switching extruder script this will operate the cutter. I also created a custom tool script that performs the retraction, recover and prime tower, snip of custom tool script below. The script also requires custom start, end, script and extruder custom end script. Little bit of OCD
;; Start custom tool change script
M211 S0;
G90 ; Return to absolute positioning
G1 X35 Y35 F6000; Extrude x mm of filament at 3 mm/s on new tool
G91 ; Switch from absolute positioning to relative positioning
G0 Z0 ; return to saved Z
G92 E0 ; Reset again extrusion distance on old tool
G1 E130 F2700 ; Recover filament by 110 mm at 30 mm/s (1800 mm/min) on old tool
G92 E0 ; Reset extrusion distance on new tool
{IF NEWTOOL=0}T0 ; Activate tool 0
G2 F900 I14 J14 E15 ; Extrude x mm of filament at 3 mm/s on new tool
G1 X1.0 Y1.0 F6000; Extrude x mm of filament at 3 mm/s on new tool
G2 F800 I13 J13 E15 ; Extrude x mm of filament at 3 mm/s on new tool
G1 X1.0 Y1.0 F6000; Extrude x mm of filament at 3 mm/s on new tool
G2 F700 I12 J12 E15 ; Extrude x mm of filament at 3 mm/s on new tool
G1 X1.0 Y1.0 F6000; Extrude x mm of filament at 3 mm/s on new tool
G2 F600 I11 J11 E0.5 ; Extrude x mm of filament at 3 mm/s on new tool
G92 E0 ; Reset extrusion distance on new tool
G1 E-4.5 F2400 ; Retract filament by 5 mm at 30 mm/s
G92 E0 ; Reset extrusion distance on new tool
G90 ; Return to absolute positioning
M211 S1
G1 F3000 X98.295 Y38.487 ; Goto last position without extrusion
G92 E0 ; Reset extrusion distance on new tool
G1 E4.5 F2400 ; Reset extrusion distance on new tool
G92 E0 ; Reset extrusion distance on new tool
;; End custom tool change script
tool change script is working great and once the whisker cutter is in place I should be able to use at high temps with no issue.