I got a sample of ninjaflex because I want to buy a rol but I i can’t print it right.

It prints granular, no fine line. It looks like my pinter head is blockt but it isnt.

I used a temperature of 220°C and 240°C

I have a felix 3.0 printer

Does knows someone know this problem

or does anyone has a solution for this?

7 Likes

Hello Tessa

You have to lower the print temperature.

I also have a Felix printer and it prints very nice with ninjaflex.

I print around 210°C and a speed of 20mm/s, no retraction.

The granular lines you have are because of the heat, the filament starts to cook in the extruder and makes airbubbles.

Hope this was helpfull.

Simon

First thing to look at is temperature. My default Felix Ninjaflex profile in cura is at 200C 95% flow and bed at 40C. I have not printed flexible filament yet and I don’t know if 200C is hot enough for ninjaflex (they say 210 is minimum range).

Second thing to check is the grip! What drive gear/wheel do you have on your extruder motor? The new grooved one should be better at guiding the filament into the hot-end, but you should take care to align it too (groove aligned with hot-end input hole)! Also check your extruder tension spring because a high tension and grip is important especially for flexible filament.

Third thing is the nozzle opening. If you are not extruding a fine line your nozzle might be semi clogged. It might be because of the material you printed previously. Heat up your hot-end to 240C and use the 0.35 mm dremel drill bit to clean your nozzle carefully. Then check the extrusion again. A side note for this. The z bed leveling calibration is also important! If the first layer is really squished then you might experience filament grinding, nozzle semi clogging and build up. If you are printing at 200 microns you want the first layer to be no less than 180 microns. Squished first layers stick to the bed surface better, but can create other side effects that might cause the problems you are having.

One more thing is print speed. Flexible filament should be printed max 20mm/s, unless you know your printer can print it faster. Cura has the lowest default setting at 30mm/s, you should change that to 20mm/s and if it still fails lower it more. A side note for this is the extruder steps per mm calibration. Calibrate it with PLA first and then test and calibrate the flow for ninjaflex. Extruder steps if not calibrated affect the print speed. If you want to extrude 10mm of flexible filament but you actually extrude 12.7mm or 8.2mm, then your speed and dimensions will not be accurate and will create problems.

There is a good video guide that explains things you should know when printing flexible filament.

If none of the above tips helped you, I am sure if you e-mail felix printers support, they will help you out. Suggest tests to do and step by step configure your printer. They have responded to my support tickets every time in 1 or 2 days!

I hope I have been helpful.

4 Likes

First of all check the temperature and grip. You need to watch the print speed I recommend 15 mm/s. You can look at a clogged nozzle by putting PLA or ABS in the print head and then try to see if it comes out semi curved or to the side. It should come straight down.

I put my money on underextrusion caused by bad filament grip. The Felix 3.0 has one big weakness: the drive gear is really bad and starts slipping as soon as there is a bit too much friction (either in the nozzle or in the feed line). I even had this problem with regular PLA. I solved it by installing a new drive gear with curved grooves (or you can upgrade to Felix 3.1).

The updated version of the drive gear is indeed much better than the old one when you want to use flex filament.

thank you all for the tips, i’m going to try these tips out and see if it gets better

It`s a tough material to print and not all 3d printers can print it. Try increasing the temperature. 260 worked for my 3d printer.

If you are seeing bubbling in the extrusion (extrudates will have a rough surface like a foam), then your filament is wet. Polyurethane (which is what ninja flex is) absorbs water very easily. Lower speed and lower temperature can help, but ideally you need to dry the filament.

I’m printing 1.75mm NinjaFlex with great results at

- 245 °C (constant)

- 30 mm/s (constant)

- with E3Dv6 hotend

- on a Prusa i3 Einstein Rework with direct extruder (no bowden)

With these settings, it comes out clear and fine (not granular) and yields a nice print quality and finish.

I noticed a few challenges finding the settings, which are:

- make sure you got the same speed for everything

- the ideal print speed depends on your print temperature and vice versa - you can (and have to) print at 255 °C or higher temperatures if you want to increase the print speed (different speed for infill and perimeters etc. don’t work because of that)

- very high temperatures will cause oozing, but still print fine at high print speeds

2 Likes

Very common problem. I suggest printing at 120% flow rate and see where that gets you, also try printing at 30-40mm/s; turn retraction distance to 1mm.

Thanks for sharing this, do you have any prints to show, I’d be really curious to see how they look. Cheers!

I have tried with: 210°C and speed 20

Tis is the result. Shoud I lower my temp some more or increase it a bit? Or change my speed?

Is this result an improvement compared to your previous settings? As I said, the default cura profile is 200C, can you try printing using the default profile? How did you set the speed to 20? It looks like the first solid layers were printed quite well, but when it started the infill layers things got worse, which tells me that you might have not slowed down the infill speed. All speeds (except travel movement speed) should be set to max 20mm/s for flexible filament. Also what percent infill are you using? I think that you might want to set the infill to 30% and above so that the print holds its shape better while printing because of being a more solid object. Look at the settings highlighted in my screenshot and give them a try.

It also looks like you may want to increase the retraction a bit. I have also found that sometimes playing with the retraction speed can help as well. Too fast, and it tends to just suck up a bubble, and then drool, too slow, and it can leave blobs. Also, make sure you have z-hop enabled, and make it at least 0.3-0.5mm. I have also found that the wipe while retracting feature in Slic3r really helps with strings. Finally, non-print move speed should be as fast as your printer can handle, as this helps to break strings.

I got a sample of filaflex. The filament specs list 220-260C temperature range.

I did a simple first print (the felix gadget) with the speed settings I suggested.

Slic3r speeds set to 20mm/s, hot end set to 225C and bed to 40C. Flow was at 0.95 and layer height at 250.

Pretty good result for a first print. I think I need 1.05 flow and the end result would be better.