MK3 and flexible filament ?
Hi all,
Can anyone from you or maybe the developers explain why the (my) mk3 can´t print any flexible material which was no issue for the mk2 ? (I have TPU and TPS - neither of those did work - I tested like 5 different spools alltogether).
Has anyone with an MK§ successfully used flexible material ?
Currently I like the new machine very much but not able to print flexible is a BIG step back from the mk2.
Cheers Richard
Re: MK3 and flexible filament ?
It should not be an issue. You did not provide much info, other than it is not working. What is happening? Do you have an mk2 as well and thats working? So I am guessing you have experience with TPUs and other flexible filaments.
Either way, it sounds like you just need to dial it in (settings may be different than the mk2) or there is a problem with the hardware/assembly.
The MK3 should print flexible filaments fine. But like I said, more info will help.
Re: MK3 and flexible filament ?
The bondtech should be able to grab/push the filament well, The hot end can definitely handle it, and the build plate is the same as mk2s.
My suspicion is your extruder build. Two things that could cause issues are any misalignment, or overly tight grip. If the pressure is too high it can deform the soft filament and cause a jam.
Re: MK3 and flexible filament ?
I have an MK2 and an MK3 yes. MK2 could handle it very well using the build in settings in slicer for flexibles. Same presets used on the mk3 - nothing. Funny thing: MK3 loads and extrudes while loading as it should - but when it comes to printing it just won´t work. Either the material is rolling around the bondtech or it comes out the side hole.
I´ve played around today with it and it just wont work.
Mats I tested:
some harder TPU: works on the mk2 and a clone of an mk2 and on the CR-10 (bowden) but not on the MK§
medium TPS: works on the clone (not tested on the mk2) - NOT on the CR-10 and NOT on the MK3
medium TPU: works on the clone and the mk2 and not on the MK3 - CR-10 untested
I have some fiberflex40d here from fiberlogy which ill test shortly and some tpu from extrudr which I also need to test out.
(might take some time)
Gimme an advise maybe: should I loosen up the springs form the bondtech for flex or tighten ?
Cheers, Richard
Re: MK3 and flexible filament ?
My mk3 is not yet here, so ymmv.
First check the alignment of the extruder rollers. Josef commented on it in other thread (extruder clicking), or re-read that part of the assembly instructions.
If that doesn’t do it, I would try loosening the bondtech. It sounds like the bondtech is gripping, but filament is squirrelling out the side. That could be alignment, or jam below caused by squished/flattened filament.
Re: MK3 and flexible filament ?
I should be getting my MK3 tomorrow. I sure hope these issues are sorted out. One of the reasons I chose the mk3 was that it was supposed to work very well with flexible filaments, I print with TPU a lot. "The extruder is now upgraded to Bondtech drive gear. It grips the filament from both sides, increasing the push force and making the printer more reliable, especially for flexible filaments"
Re: MK3 and flexible filament ?
I don't know if I would call it an issue. An extruder with a short direct path between bondtech extruder gears to an e3dv6 hot end should not have issues with flex filaments.
However, several things during assembly could make it not work well:
It really depends on what the issue is. If the hot end is jamming (clicking extruder), then it's likely that there is a skewed path, or the bondtech is squeezing the filament out of shape and it can't fit in the (tight) tolerances of the hot end. If the hot end simply isn't feeding (extruder slipping on the filament), could be too little tension.
I'm guessing the former. I haven't tried flex yet (I only have 3mm ninjaflex, no 1.75mm yet) so ymmv.
Has anybody successfully printed TPU or other flex?
Re: MK3 and flexible filament ?
I can confirm that i cannot print with flexi fill 98A
It extrudes for a while but very soon the filament gets tangled around the bondtech gears
Re: MK3 and flexible filament ?
I've printed a few little pieces just fine with TPE (eSUN "eLastic": https://www.amazon.com/gp/product/B01N1807E2 ) at 220 degrees (225 first layer), using the glue stick for bed adhesion. It extruded fine but I got a lot of strings so any tips would be appreciated.
Re: MK3 and flexible filament ?
I can confirm that I cannot print with flex fill 98A
It extrudes for a while but very soon the filament gets tangled around the bond-tech gears
[/quote]
Did you change any settings such as turning off z-hop, retraction, adjust the tension on the extruder tensioner? Just wondering. I am printing my first test with glue stick lightly smeared on the bed(lesson learned from MK2), and all I did was select the flex in the filament and slowed the travel to 1000. I am printing .2 layer height with everything else stock. So far so good. The filament is SaintSmart TPU 98a for reference and I am printing at 230/50. I did bump the fan to 30% after a couple of layers (another lesson from previous experience). Hopefully, you were just trying to print to fast. I think the setup should be ideal and much better than MK2 which worked well IMHO. I just had to learn patience and realize that quick was not an option. Hope this helps or encourages you to try again. Good luck. I'll let[/img] you know how it comes out. My first Octopus. Obligatory.
Yes and any stringing tips woudl be appreciated. I am gussing either kill retraction and let linear feed do its business (and adjust K) or more of it, or possible less temperature.
Re: MK3 and flexible filament ?
I have printed NinjaFlex, but I had to slow way down - 10 mm/s! 20 mm/s generated back-pressure, followed by the filament coming out the side of the extruder. The issue isn't the BondTech gears - they are great - I think it's that the filament path isn't fully constrained around the gears. Well, and of course, that NinjaFlex is absurdly soft.
Re: MK3 and flexible filament ?
I have printed NinjaFlex, but I had to slow way down - 10 mm/s! 20 mm/s generated back-pressure, followed by the filament coming out the side of the extruder. The issue isn't the BondTech gears - they are great - I think it's that the filament path isn't fully constrained around the gears. Well, and of course, that NinjaFlex is absurdly soft.
Gotta be something that can be done. Perhaps a better formed PTFE tube up to the gears. Will try something softer tomorrow. My print came out great, albeit a little string. Changed k to 15 and disabled retraction. So far half way done and it looks clean as can be. So perhaps their is hope. I am happy so far for my first two attempts, and in all fairness I was no expert on FF before.
Re: MK3 and flexible filament ?
Firmware RC5 (150b) has LA disabled to improve Octoprint stability (experiment), but RC4 (143) still has LA.
Just got a spool of NinjaFlex I want to try in the near feature. Looking forward to hear about your result and recommendations 😀
Have a look at my models on Printables.com 😉
Re: MK3 and flexible filament ?
I had great luck with eSun eFlex TPU (Shore A 87). I just sliced it with Prusa Control and the Flex material setting. Looking at the gcode it is printing at about 25mm/s. However I was able to turn the speed up to about 125% on the machine. Anything faster and it would jam the extruder. There was some stringing, but not too bad. Much better than my previous experience with this same roll on a Maker Select. The MK3 did seem to respond positively to me loosening the pressure on the Bondtech gears.
Re: MK3 and flexible filament ?
I must just be lucky. I printed two octopi with SS TPU 98a without issue. The second one is shown here cleaned up a bit by using 15 as a K factor. Worked great. Just a little glue stick as a base. Hope they can help you figure out what is going on, but mine is working well with exception to the manual load/unload (not a big deal). Good luck! I am also using the default TPU settings with the acceleration set to 1000, and nothing else. I am still using firmware 143B by the way as linear advance is working for me fine from SD.
Re: MK3 and flexible filament ?
I printed ninjaflex with no issues. Printed a nice frog just to see if I could.
Re: MK3 and flexible filament ?
I printed ninjaflex with no issues. Printed a nice frog just to see if I could.
Could you share more about this print?
Which slicer, which settings, any mods, print bed treatment?
Thnx!
Re: MK3 and flexible filament ?
I tried out Ninjaflex on my MK3 as well, had pretty good luck, I printed very slow 10mm/s and 60mm/s travel as the creator of the part I printed had suggested. Could us a little tweaking still as there was a little stringing, but not bad first print. And the robot hand is a really cool design.
Re: MK3 and flexible filament ?
I printed ninjaflex with no issues. Printed a nice frog just to see if I could.
Could you share more about this print?
Which slicer, which settings, any mods, print bed treatment?
Thnx!
Sure.
Slicer: Slick3r PE 1.86
Bed prepared with light glue stick material for ease of removal.
I am pretty sure that the speed is also limited by the volumetric rate overall, so that may be the key
Re: MK3 and flexible filament ?
Continued