Elastic filaments opened brand new areas for 3D printing. We are finally able to print something that bends, compresses and stretches. While TPE (ThermoPlastic Elastomer) filaments like NinjaFlex or FlexiSmart are still about 4 times more expensive than plain old PLA, they are not so expensive not to give them a try.
Unfortunately, due to the fact that they are elastic even before melted and extruded, they require special printing conditions. During my experiments with FlexiSmart I've came down to following conclusions:
- Because TPE is elastic, flow through the nozzle has to be as smooth as possible. If not, it will coil inside extruder
- Bowden extruder system greatly increases chance of failure. Friction of bowden, while small enough for ABS or PLA, is too big for TPE. Filament will coil. Direct extruder gives less chance of failure
- One has to pay big attention to the distance between extruder nozzle and bed. Usually it has to be a litter bigger that for PLA or ABS. In all the cases when I was switching from PLA to TPE, I had to raise nozzle a little. If not, TPE coiled. TPE has better initial adhesion than PLA, so rising a nozzle does not have side effects
- Filament retraction is a huge NO NO. Disable retraction since it will increase the chance of coiling significantly
- With no retraction it is a good idea to enable Combing. Nozzle, instead of taking the shortest route to travel, dripping TPE everywhere, will move above already printed layer. This greatly improves print quality
- Top printing speed is
30mm/s, but I recommend slower speeds. I have best results when printing at
25mm/squality is still acceptable, but degradation starts to be visible
- I had best results of TPE printing on glass with
220degnozzle temperature and
- Not everything can be printed with elastic filament. Any thin vertical structure will come deformed. After all, it will move during printing due to a friction with extruder nozzle
While I was printing with FlexiSmart, almost all points from the above list will be true for other TPE (NinjaFlex). Temperatures might be slightly different, but general rules applies.