I’ve been experimenting with NinjaFlex filament and wanted to share my experience using it on my Printrbot Plus Metal with a V2 aluminum extruder. I’ve had pretty good success and wanted to share some pictures of my print using NinjaFlex of the Treefrog by MorenaP from Thingiverse:
I’d encourage you to try NinjaFlex filament as it is amazing to be able to create objects that are flexible and bendable. The resulting object is also super strong and resistent to tear. NinjaFlex makes this frog almost seem lifelike when you hold it!
Okay, here are the dos and don’t that I’ve discovered to have a good experience with NinjaFlex:
DO modify your extruder to remove the gap in the Printrbot V1 aluminum extruder. You have several options including (search Internet for “NinjaFlex extruder”) filling the gap with Sugru, printing an adapter to remove the extra room in the extruder or upgrading to the V2 Printrbot extruder. I highly recommend upgrading your extruder to the Printrbot V2 aluminum extruder because NinjaFlex is expensive filament, so why mess around wasting time and filament when you could have better success and less hassle with an upgraded extruder. The filament hole in the Printrbot V2 aluminum extruder is much smaller diameter than the Printrbot V1 extruder filament hole. This smaller hole and tighter extruder design does a better job of feeding flexible filament through the direct drive and into the hotend without allowing the filament to get bent like a pretzel.
DON’T Feed too much filament through your extruder too quickly! I made a mistake when I loaded the filament for the fist time and while experimenting, manually extruding NinjaFlex using my CAM software (Simplify3D). Initially it was extruding 10mm at a time without any issue, but as I continued to extrude 10mm over and over without stopping, the extrusion stopped. My extruder stepper motor was not able to turn. Turns out I was feeding filament too quickly through the hotend. Unlike PLA or ABS, you cannot extrude too quickly. So if you want to prime your hotend, for example, you need to be very patient and extrude 10mm, wait for a few seconds then extrude 10 again. If you extrude too much too quickly, you will likely get a kink in your filament. In my case, I had to disassemble my extruder in order to remove the filament that was tangled.
DO prime your extruder if you are switching from a different filament. Always do your priming of NinjaFlex slowly to avoid a jam. I typically run a total of 200mm through my extruder to make sure the previous filament is fully flushed prior to printing with a new filament. With NinjaFlex, you need to manually extrude 10mm and wait a few seconds before extruding again. Priming the extruder is super important if you are switching from a previous filament that is not NinjaFlex. As always, when flushing your hotend, remember that you should be extruding at the highest temperature required by your previous filament or new filament…then adjust to the appropriate temperature for your new filament once flushed.
DON’T have your hotend too hot or you will get a lot of NinjaFlex drool…meaning filament will drip from your nozzle and leave globs on your print. Too hot can also make your filament even more flexible and cause it to jam. And don’t have your hotend too cool or it will not heat your filament quickly enough, which will cause a backup and cause your filament to get jammed in your direct drive gear. 215C seems to work well for me (see more details below).
DO set your CAM software appropriately for NinjaFlex. Here are the key differences I’ve discovered through my experimentation:
- Set hotend to 217C for your first layer at .3mm (I double the first layer height using first layer height of 200% in Simplify3D)
- Set hotend to 215C for subsequent layers at .15mm
- Turn on retraction with retraction distance 1.5mm and retraction speed at 1800mm/minute
- Definitely use a skirt of 3-5 outlines depending on the size of the object. Use fewer outlines for larger objects and more outlines for smaller objects.
- Infill will vary. Less infill makes your object more squishy. 20% infill is a good place to start.
- Some heat on the bed seems to help make NinjaFlex stick, I’ve had great successful at 40C.
- On the bed, I use a bit of hairspray on blue painter’s tape and get good adhesion and easy release after the print finishes
- Turn your fan on for layers 2+. You want the fan to be off for the first layer to get good adhesion.
- Set default printing speed to 900mm/sec
- Set default X/Y movement speed to any speed you want. I leave mine at the default of 3600mm/sec. You want your nozzle to move very quickly while traveling and not extruding to minimize drool/globs on your object.
DON’T get discouraged if you have some initial failures printing NinjaFlex. Remember to go slowly and don’t push too much filament through your extruder too quickly! And if it gets jammed, no sweat, just let things cool, take the extruder apart and it should be easy to untangle any filament that is jammed.
DO Share your experiences so we can learn from one another!