Re: MK3 and flexible filament ?
After reading this thread the other day I tried printing some Ninjaflex on my MK3 and had great success. I simply created a Slic3r PE profile with the printing guidelines from the ninjatek site, maxed out travel speed for non-print moves, and disabled retraction. It can be a little stringy depending on the model, but no failed prints 😎 .
Re: MK3 and flexible filament ?
I bought some of the Flexfill 98A with my MK3 and have had frustrations also. Much less reliable than the rigid plastic filaments.
Have had same issue as others, material bends before it gets to the nozzle and then bird nests or coming out the side of the extruder. I used the settings from the datasheet, 230C nozzle temp, 50C bed temp, 20 mm/s print speed, no retract. I still get the issue, I think as others have observed there needs to be a tube catching the filament right out of the Bondtech drive gears so it can't escape.
I had limited success going super slow - 15 mm/s and printing a simple ring. Larger parts that take a couple of hours have all failed at some point (same failure mode every time with the material kinking and not going into the back of the nozzle.
Re: MK3 and flexible filament ?
After printing multiple medium size parts with Filamentum Flexfill 98A I get consistently good results at 15 mm/s. At 20 mm/s I was having filament buckling and going sideways instead of into the nozzle.
I think the path between gears and nozzle is not as constrained as it should be, may mess with a longer PTFE tube at some point. Here are the specs that have worked for me in Cura.
Nozzle: 230C
Bed: 50C
Speed: 15 mm/s [Infill is 15 mm/s, Perimeter is auto-set by cura to like 10 mm/s]
Retract: off
Re: MK3 and flexible filament ?
Ok seems like I found a potential solution - a longer V-shape PTFE tube to the hotend.
The PTFE tube supplied with my MK3 was one-to-two Milimeters to short, resulting in a gap in the filament path. This gap was used by the filament to escape.
In my case I had some spare PTFE tube and started to cut a v-shape at the end of it. I recommend to start with this part, inserting the tube to check if it is a fit. Then cut to the right length (carefull with this, so that you don't end up too short and having to redo the V-shape). The result is a pretty good enclosing filament path.
This is how it looks in my extruder:
The first print succeeded, now I'll continue testing.
Wishes to Prusa:
- Adopt the V-shape as I did, I'm pretty sure machine cut would be sooo much better.
- Make Extruder disassembly and assembly easier in a built machine.
Good luck everyone
Re: MK3 and flexible filament ?
I did the same thing, the PTFE tubing was a couple of millimetres too short and the filament kept going everywhere but the hotend. Got another bit of PTFE from E3D and made it a tad longer, I still cut square as I couldn't make a v shape nicely. It has been working fine ever since with Ninjaflex, 15 mm/s @ 230 C, no retraction, bed 45 C. The ninjaflex can stick like hell to the pei though. Quality I would say is excellent. Machine is excellent though I agree with previous posts comments, taking the extruder apart is a bit of a pain. At this point I don't think will need to this for some time.
😀
Jer
Re: MK3 and flexible filament ?
This is how it looks in my extruder:
20180221_100518604_iOS.jpg
Good luck everyone
My tube entry got smashed before, there was a really big gap. Took a ptfe tube, cutted 51-52mm and made the shapes on top and bottom end.
Very good now. It was a pain to print tonight...
Re: MK3 and flexible filament ?
This topic already had been heavily discussed in that thread:
There are some different approaches of resolving this issue, listed in that thread.
You can find mine there:
https://www.thingiverse.com/thing:2905638
it's a design where you don't have to change to much parts, and its Prusa standards compatible, and had awesome feedback so far. I also made a Video about flexibles (very rough, sry 4 bad quality), eith some other tips beyond the extruder, you can find it there:
I'm working on a version based on the R3, but it'll take some time, so stay tuned.
hope this helps out a bit
Re: MK3 and flexible filament ?
Does someone has speed information with flexible filament with the new official Prusa part version? Does it really help that much?
I ordered the part just to see for myself, but I do not know what to expect. Currently I get good results at printing speeds around 13mm/s (with the old extruder with big gap between the gears and the actual extruder), which is really slow, compared to the speeds with ridgid filament. I hope to improve that with the new official Prusa version of the extruder body. I don't need 100mm/s but around 40 would already be great (with 98A filament).
Re: MK3 and flexible filament ?
I don't know about printing flex that fast. but then again. I'm just fine with it working, even if it does take longer.
I have a Prusa,therefore I research.
Re: MK3 and flexible filament ?
Similar to tim.5k I cut mine with a V shape in it. Pic attached. Currently making my way through a benchy and fingers crossed it's looking positive.
Just used the standard flex filament setting in Slic3r. No changes for the Ninjaflex I'm using so maybe it's a bit hotter than it should be but seems to be printing ok.
RE: MK3 and flexible filament ?
I am a new MK3S user. Put the kit together, and ran several prints using the out of the box PLA filament, everything works great. My next goal was to print a phone case with flexible material (Sain Smart TPU, from Amazon). I followed @chuck-w post, to set the parameters:
I used the Slic3r included profile for semiflex/flexfill as a starting point and then cranked the nozzle to 230 first and all layers and the bed to 65 first and all also.
Loosened the extruder idler screws...
When I started to print, at first everything looked good, for the first minute or so. Then, I heard a clicking sound from the extruder, and it was no longer feeding material to the hotend. Motion continued, but no material flow. I immediately stopped the print, and extracted the filament, then printed something with PLA, to make sure I hadn't broken something.
What is the clicking sound from the extruder, why did it stop feeding the flex material, and what should I do to succeed?
RE: MK3 and flexible filament ?
I just figured out a simple solution to flexible filament problems (clicking + not feeding).
I have an MK2 and an MK3. I usually use my MK2 to print flexible filaments because they print slowly and I can print PETG stuff on my MK3 in the meanwhile. The MK2 prints flexible filaments great…no problems.
But I decided to print eSun Elastic filament tonite on the MK3 and I got clicking and minimal feed-through or no feed-through at all.
Then it occurred to me the flex was set to around 210 and maybe that wasn't high enough to push out the old PETG in the nozzle.
I unloaded the flexible filament and ran some eSun Cleaning filament through at about 5 degrees higher than my normal PETG temperature. Voila! I am suddenly printing perfectly with the eSun eLastic filament at 230 degrees.
So the problem was a partially clogged nozzle and the solution was to use cleaning filament at PETG temp before using flexible filament. And it reminds me that in the past I have often run the cleaning filament through my MK2 but not so often on my poor MK3.
Hope this helps someone down the road.
Maxim