Experiments with Flexible Filament

I’ve had this roll of flexible Ninjaflex filament sitting around for a while, which I used to create some grippy feet for my bug robot. Somebody had asked me to make them a case for their aging Iphone 4, which they didn’t want to spend any further money on, so it seemed like a good excuse to pull the stuff out again and experiment with making it print well. the other time I used Ninjaflex, the results were messy and inaccurate, but they did the job. After tweaking the settings in Cura over a few test prints, I was able to improve things significantly.

The biggest improvement was not in software at all, however. I was having several issues with the filament jamming in my printer’s extruder, as it’s very flexible (hence the name…) and prone to buckling when compressed. to solve this, I modified my printer’s extruder to include a guide tube. As you can see this improved reliability by a large amount. I felt fine leaving the printer going for the 4 hours it took to make this.

Conclusions:

• print slowly! the rubber-like properties of NinjaFlex make it slip on the extruder if the flow-rate is too high.
• avoid prints with large overhangs and small unsupported parts. you can see what happens to them below.
• keep the filament mounted above the printer, to prevent it from snagging.