Has anyone had luck printing this material? I must assume that answer is yes. I cannot find settings that work. clogs / extruder gear skipping. i’ve tried so many different temps and settings. still no luck. (pretty much everything in the 220-232 range). I normally print ninjaflex at 225 with no issues (other than your typical cat hairs from this type of filament).
i think i figured it out. my front extruder was WAY to close to the bed. everything needed to be recalibrated. Back to the calibration squares I went. I think I’m in better shape now. fingers crossed, heading into a bigger test print.
(FWIW - i still not too sure about this material. I’ve had more success with the pure ninjaflex than the semiflex).
Alright. Things look a lot better. The jams were definitely stemming from the extruder being too close to the bed. Once both extruder heads were properly leveled and re-calibrated it printed better. I still am printing at a fairly high temp - 232 (in comparison to the ninjaflex - 225), but I’m able to get some long running flexible-only material prints fine now.
The default Cura settings has all sorts of temp variations that cause me some issues (standby temp, initial layer temp, start printing temp, etc.). I’ve modified all of them to be the same temp for better results. I’m curious what settings others use. It may very well be that I was tweaking unnecessarily as my primary issue was extruder head leveling.
(continuing the conversation with myself
I’m still struggling to print this semiflex stuff. I had one successful 3.5 hour print. the second attempt clogged less than a quarter of the way into the print. I reduced the size of the print and same issue.
However, I now believe my problem is TOO high temps. I think my original issue was the tool head being too close to the bed and in an attempt to resolve this I kept pushing the temp up. Now that the head is level, I’m going to try lower temps again in hopes to fix. running a test print now at 226.
Which tool-head are you currently using?
I’m using the flexydually v2. I’m attempting a T1 (flexible only) print. I’m still struggling.
Im printing small (20x20x15) cube like structures (custom shape).
I’ve had mixed success. To test I print 1 cube. But I’m trying to print grids of 8. I tried grid of 4, 8, 16. I will be happy with 8 in a batch.
At 232 after getting through the leveling stuff I was able to print a batch of 8 (not great quality and stringy). A second attempt jammed a few layers in.
At 226 I produced the best quality single cube to date. Was sure I nailed it. Tried a batch of 8 and it clogged a few layers in.
I’m pretty confident in bed level at this point.
After each jam I’ve turned up heat high and cleaned nozzle a bit. Make sure I can manually extrude about 50mm clean and start again.
At this point I’m struggling to figure out where to go from here? Cooler / hotter? Tune some other parameter? Something needs adjustment?
What version of Cura are you using and which profile do you have selected?
It almost sounds like you are printing too fast. Ninjaflex doesn’t usually do well if you you are trying to print it at the same speed as say PLA or ABS.
Started with Standard but pretty heavily modified at this point.
I suspected print speed as well, but the FASTEST i’m printing is 16mm/s. inflill is 14, wall 8, etc.
should be slow enough for ninja stuff.
my only thought now is more temp adjustments or maybe fan settings (thinking heat creap?? jack up fan speeds?)
Since this is happening more with multiple models on the bed it’s possible this is related to retractions also. Especially when printing smaller parts there are going to be more retractions in a smaller time-frame.
Have you adjusted any retraction settings, what are they set to now?
Since you’re having success printing one of them and you said the parts were relatively small you may also have luck using the One at a Time Print sequence mode. This is located under Special Modes in Cura. This mode will print each part that you put on the bed to completion and then move on to the next model. This should also eliminate the stringing between models since the printer will only move from one model to the next once the current part is finished.
You may also want to do some cold-pulls. Does the filament come out as a straight line when you manually extrude or does it pig-tail back and touch the extruder?
I haven’t tweaked any of the off-the-shelf retraction settings. (retraction enabled, 2mm distance, 4mm/s speed, 1.2 mm of minimum travel, maximum retraction count of 90). Since I’m not switching nozzles, I don’t believe the nozzle retraction settings are used at all.
I can try disabling retraction and see how that goes.
I can also try the one at a time print sequence mode. I’ve never tried this mode. I might need to spread them out but that’s fine.
I’ll give that a try as well. Usually when the head jams, I’ll do the following steps:
- heat up and retract filament all the way.
- Cut off the grinded parts on the filament.
- using tweezers and brush will clean away nozzle (pull off caked on stuff). Also will use some compressed air to blow away any particles / dust left around.
- then turn up heat past a normal melting point (say 240 or higher) and extrude about 100mm (until it comes out straight and clean).
- I’ll reduce temp to normal printing temp (226) and extrude another 50mm or so (ensuring it’s still straight feed).
- From here, I’ll adjust settings in print profile and do a test print.
- When test print is successful, I’ll move to the multiple models gcode with the adjusted settings.
I haven’t attempted a cold pull. I will try that out.
are there any other cleaning tips I should attempt on these? information on maintenance of the flexydually v2 is sparse. (the gears don’t look warn btw).
thanks again for your help. there are a few things to attempt here.
the single model print at 226 was really good quality so I am hopeful (I’d go as far as saying it was one of the best flexible prints I’ve ever done. I was really bummed when the multi model failed after this).
For a FlexyStruder I’ve included below the procedure for cleaning out the inside of the nozzle, or cold-pulls as they are called.
Cold pulls: If the filament measures close to 2.85mm, then you can feed it back into the tool head, while the hot end is at operating temperature.
Then let the filament sit for 1 minute and then cool the hot end down to 140C and then manually turn the large herring bone gear and pull on the filament to remove it.
This will clean up the residual filament in the tool head. You will need to do this 3 or 4 times to clear the hot end.
Then you can load your filament and make sure that your Z offset is correct for the first layer. And then run the temperature at 240C for your next print and see how the filament does.
240c is pretty high for flexible. is running this high the recommendation after cold pull? or should I look to run it closer to the range I normally have (225-230)
another question on cleaning:
is there a recommendation on cleaning the nozzle - external/bottom of extruder? I’ve heard mixed things on whether it’s necessary / helps and I know enough that metal brushes shouldn’t be used for risk of shorting thermistor. I also have heard that removal of the nozzle is not recommended either. what is the recommendation?
NinjaTek on their website recommends an extruder temperature: 225°C – 235°C for their filaments. Since you’re having jams at 225-230 an adjustment of 5-10 degrees should be fine.
To clean filament off of the nozzle/hotend heat up the hot end to the extrusion temperature for the filament you are using and then turn the printer off. Then use a blue shop paper towel, (you can get some from auto zone or places like that) to wipe off the excess filament and then use a piece of “Scotch Brite” pad to wipe the nozzle off, as it is non conductive and will clean the bottom of the nozzle well. Please be careful for the heater and thermistor wires as they are very small and will break easily. You are welcome to do this with the tool head off of the printer, if that will help you access different parts of the toolhead. Make sure to avoid using a wire brush to clean the hot end as it can cause a short back to the RAMBo.
Also just a quick note that we sometimes see people use acetone for cleaning. Acetone does dissolve ABS, but it can also dissolve the wires on the heater block, so we do not recommend using it on the whole hotend. Here is our repair disclaimer for just in case:
At Aleph Objects, Inc. we respect your freedom to modify your LulzBot 3D printer. It is important to know that any modifications or attempted repairs that cause accidental or intentional damage are not covered under the Warranty.
We don’t recommend removing the nozzle on the hexagon hot end because it can cause damage to the hot end. The nozzle requires very precise torque and it is very easy to strip the threading on the hot end if over-torqued. We don’t want to encourage any procedure that can damage the printer, so we do not sell replacement nozzles for the Hexagon hot end. Although they can be sourced from other merchants such as reprapdiscount.com. But be aware that any damage caused while switching out the nozzle is not covered under the warranty