RE: TPU (Ninjatek Ninjaflex specifically) on the XL
@frio Yes, it wasn't to bad to clean off though. I get the ziplines also but they only seem to happen on the priming extrusion for each nozzle but still annoying that I have to try to catch them with tweezers so my first layer doesn't get laid down on top of them. that under extrusion is what I saw with default ninjalex profile, some colors more than others. The MVS of 1.2 really took care of that for me. The periodic jamming(again some colors more than others) was taken care of by setting retraction length to 1.5(like the sainsmart) from 3.5, and the retraction speed down from 60 to 20. I've not tried any mods at this point. I'm convinced I can probably inch the MVS up from 1.2 but when I print this crap I don't want to have to do it multiple times so I'd prefer reliable. Fun thing was it wasn't the ninjaflex that jammed this last time, it was the sainsmart. I think I may have gotten a partial clog in there. I think I'm going to try bring down the temp since 227 is still higher than the spool is rated for. I don't know where prusa got these settings. I still have to remember to go into the printer gcode each time I create a new project and change the FLEX starting/probing temp from 210 back ddown to 175 or it does the build plate with blobs while it's probing.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
Hi All,
So I had time this past weekend to tweak my setup. I've upped the print temp to 238-240'C and increased the pressure on the idler screws. Yes, even though Prusa says to decrease the tension, for the Prusa XL's tool, the opposite helps. I do have to back it off when I load in PLA so I'm not crushing the filament. So my jams printing TPU and TPE have almost completely gone away.
I'm still getting some, what I think, are under-extrusions. Even at 240'C this still happens. Room temp is 20'C.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
Hi All,
So I had time this past weekend to tweak my setup. I've upped the print temp to 238-240'C and increased the pressure on the idler screws. Yes, even though Prusa says to decrease the tension, for the Prusa XL's tool, the opposite helps. I do have to back it off when I load in PLA so I'm not crushing the filament. So my jams printing TPU and TPE have almost completely gone away.
I'm still getting some, what I think, are under-extrusions. Even at 240'C this still happens. Room temp is 20'C.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
@slam I dialed in my idler tension by printing 100mm square on each extruder in prusament petg. I use that as my control. and that tension works for ninjaflex as well. Since you said you're not printing in an enclosure, it makes ense you might have to adjust your temp from the 238, but I think the primary jams are caused by the stock retraction settings. I'm busy with work this week but I still might try going back to a higher mvs than the 1.2. But now it's pretty reliable and that's really most important to me.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
The only time I got a jam with flex filaments is when printing 83A through the OEM tube, bypassing the filament sensor. The filament got so tight that it stretched, making it wind around the gear in a rather difficult to remove fashion. Since going to an overhead filament feed, I haven't had the slightest problem with flexible filaments. I keep the stock settings on the idler tension.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
what brand of filament is that 83A? is that ninjatek Edge?
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
eSun TPE. Seems to work pretty well.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
Well, after 10 stupid little cubes and couple more cancelled stupid little cubes I think I have something decent to live with. The following are feeding the filament directly into the extruder and with filament sensors off since I still could not get the sensor on the tool head to detect the filament. Quite honestly I did not see much of a difference when I stopped feeding through the PTFE in one test where that was the only change. I kept feeding it this way though because of the major PITA it is to feed through it.
One thing I realized was the filament is way out of spec. It is genuine NinjaTek NinjaFlex so I was surprised, especially since I had no issues with this same spool on the MK3. Ii measures an average of ~1.66mm, but honestly it is all over the place but no where did I find 1.75mm. With that set things immediately got a bit better. I now wonder if this stuff has some sort of half life or something since it a few years old 🤣
I was able to get rid of the zip line by setting 'Retraction when tool is disabled' to 10mm. Yay!
I'm going to run a Benchy with it tomorrow after it sits in the dryer again over night If that is successful, or reasonably so, I'll probably post the settings and a 3MF over in Printables. If not, and if anyone is interested, I'll attach it here.
How's this for a spool holder!
The circles are where detractions are happening. and leaving a gap I increased the retraction which got rid of the blobs when it does the goofy circular retraction moves, which BTW completely ignore 'Avoid Crossing Perimeters'. The only way I could find to get rid of them is by setting retractions to zero, which led to other issues. Anyway, this caused gaps where it detracted so I added some 'Detraction extra length' which solved that, just need a little more.
This last test was done with lightning infill just to cause more restractions. It certainly wasn't the best looking infill but it did do it's job. the lack of infill is why the walls look a bit wonky. When using grid infill this was not an issue.
Certainly an improvement over what I was getting previously.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
NinjaTek NinjaFlex PrusaSlicer Printer Profile for the Prusa XL
Not perfect but certainly better I think.
This pic a few minutes after it finished, still attached to the bed. Look Ma, no zip line!
Looks like a small blob attached at the end of the rod holder, probably released from the mess that builds up on the nozzle when it moves from the purge line to the print area. I have no idea how to prevent this aside from modifying the start gcode, but I do not want to have to remember to select a different printer profile when there is TPU loaded. This and the cube tests are the first time the XL has seen TPU, and it is the only time I have ever had this happen. It happened on every test cube too and the reason this print was moved nearer the purge line end. Pressure build up in the nozzle is all I can think of as the cause.
Some reasonably light stringing which IMO is acceptable with this filament. I was not watching when the chimney was printing so I have no idea how it got that odd, whatever it is. Guessing it was wobbling as the nozzle circled around it.
Looks like the bow is a little oddly shaped too. There was some curling there as it printed so possible some more cooling would help. Same for the bridging, not bad but probably better with some more cooling.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
@frio that's not bad at all. I've not tried one with my settings recently. I'm kind of getting tired of printing tpu to be honest. really makes you appreciate just how simple rigid filament is in comparison.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
I'm kind of getting tired of printing tpu to be honest. really makes you appreciate just how simple rigid filament is in comparison.
Amen... and amen!
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
@frio that's not bad at all. I've not tried one with my settings recently. I'm kind of getting tired of printing tpu to be honest. really makes you appreciate just how simple rigid filament is in comparison.
Reading about all the trouble people have been having printing TPU, I've been wondering about 2.85 mm printheads...
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
does seem like it would be less prone to jamming
@frio that's not bad at all. I've not tried one with my settings recently. I'm kind of getting tired of printing tpu to be honest. really makes you appreciate just how simple rigid filament is in comparison.
Reading about all the trouble people have been having printing TPU, I've been wondering about 2.85 mm printheads...
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
I am trying to use extrudr TPU medium hard (98A), which can be used in the PTFE tubing quite easily (sensor on toolhead still needs to be off otherwise it will sometimes detect filament missing). However, I get quite a lot of stringing on it. See below, black PLA with red extrudr medium hard TPU. I try to adjust the nozzle seal on the tool to get low leakage there, but already the leaking on the way to and from the printed part and the wiping tower are quite troublesome.
Any ideas how to enhance that? (profile used was the predefined one in Prusaslicer for extruder TPU medium).
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
I noticed in all the FLEX filament profiles the "retract on park" settings are disabled or set to only 2.5mm, which is not enough to pull it out of the melt zone. On regular filament this defaults to 20mm. I think this is the reason for the stringing, since the filament stays in the melt zone all the time while the toolhead cools down and warms up again in the dock. The silicone wipers won't help much, because TPU is really runny.
Unfortunately you cannot just activate the park retraction (I tried 12mm and 20mm with 98A TPU, on the off-chance it was just an oversight). In my case I get heatcreep after a few minutes of printing every time. Probably the filament is too flexible for these fast&long retracts and parts of it just stay in the melt zone, leading to build-up, heat transfer further up the tube and eventual clogging.
I couldn't come up with a solution for this yet.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
I've only done a small amount of TPU printing (Flexfill 98A), and apart from the side filament sensor drag, it seemed to be uneventful. But they were not demanding prints. To deal with the side filament sensor drag, I use this mod (my model, see description for origin of the idea), which I've had in place for some weeks on all 5 tools with no problems:
https://www.printables.com/model/700838-xl-side-filament-sensor-with-reduced-force-magneti
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
@tg73, multi or single color? The problem stevQ describes seems to be multicolor-specific. I have no problems in single colour prints at all, almost everything stock (Obxidian nozzles 0.4mm).
RE:
Yes, Single color is quite easy, multi color was my issue. However, meanwhile I printed a temperature tower and heavily reduced the printing temperature (I think 20K less now) which helped quite a lot with both, stringing and leakage when being parked.
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
Single colour. I was trying to express that I was aware I couldn't contribute to this TPU discussion in general, and just wanted to share the side filament sensor mod in case it was of use/interest. For me, loading Flexfill 98A through the stock side extruder was unacceptably tortuous, hence the mod.
@tg73, multi or single color? The problem stevQ describes seems to be multicolor-specific. I have no problems in single colour prints at all, almost everything stock (Obxidian nozzles 0.4mm).
RE: TPU (Ninjatek Ninjaflex specifically) on the XL
Ah I see. I'm about to try 82A, your mod is already on the list to try. With 98A I had zero problems. I have a suspicion Prusa quietly changed the printed part in the filament sensor, maybe I have less issues because my printer is newer.