Does anyone have a screenshot or can give me there settings for printing TPU or ninjaflex. Ill take cura, simplify3d or whatever settings you have on printing this devil filament. Also what size nozzle do you use? My settings right now are 235/50, at 10mm/s, no retraction, using a .4 nozzle.
I ran Ninjaflex with a .4mm nozzle.
Extrusion multiplier of 1.1 and extrusion width of .5mm
.6 retraction @2400mm/min and 1mm coast
.2mm layer height.
Nozzle temp 250c
No cooling
20mm/sec speed.
I'm printing TPU from Creality and found the following: even with a perfectly calibrated extruder, the extrusion factor must be adjusted waaaay down, at the moment it is on 0.75! This is with a direct drive and a 0.6mm nozzle.
I started at 1.00, but I kept getting blobs that got stuck to the nozzle while it was moving, specially at the start and end of moves and where the layer change happens. Those blobs were then the reason the print starts flexing away from the nozzle when it passes and then it deposits the tpu next to the perimeter,in thin air...
Then by adjusting the flow-rate down to 80 and 75% on the control box I get much better results, no blobs and spilling.
Retraction is 4mm
Another thing is cooling: at first I used 40% but it is now up to 100% ( 2 fans on either side)and this helps against curling of any end of a perimeter and where the nozzle returns.
for least amount of frustration, and a chance at success, a ,5mm nozzle is the minimum I will use and I prefer the .75 on my makergear.
I have attached a factory file of a door stop bumper I modeled and fabricated in NF . This uses the .75 nozzle ..
zemlin wrote: ↑Tue Jun 23, 2020 11:22 am
With so much disparity in the responses, looks like you might just have to start printing and figure out what works for you.
How soft is the filament? Are you using a gravity feeding method?
I've personally found that if I hang any spool TPU above my extruder and just let gravity feed the filament into my hotend. Although, I'm personally using a direct drive hotend so take that into consideration as well.
But I would definitely check your filament tension to see if you should make any adjustments. TPU can sometimes be really tricky to setup but once you've dialed it in you'll be set!