Flexible Filament?

Has anyone had any luck with flexible filament? I want to make some “ski bones” and think it’s a good candidate for the flexible filaments. Can the MK8/MP3DP print it? Is it rubbery enough that it would work for a few sets of ski bones?


I haven’t, but those ski bones seem like an awesome thing to have. I hate when the skis open like that.

I could buy them - they aren’t that expensive and available locally but what’s the fun in that when you have a 3d printer? hahaha

I’ve used them in the past (you think I can find them now though?). They work great. The other ones that work great are these padded/rubberized velcro wrap things that also connect a shoulder strap so you can sling your skis/board and trudge to the hill. But for me I just need the ski bones so I can toss all of our skis into the rooftop box and they won’t all beat each other up.

I have tried a few different types.

I have had horrible luck with ninja flex. Great stuff but the only way I got it to work on any of my printers was to buy a separate print head that was designed just for ninja flex. Very flexible very stretchy very strong stuff. Hard for most printers to print especially in 1.75 mm spools. It is like trying to shove a cooked noodle into an extruder. It squishes and popps out the side of your extruder in ways you would think is impossible. I have a spool of it. I could send you a couple feet if you want to test it. I don’t think it would work well for ski bones anyway. Too flexible.

But I have also used “soft PLA” it is a semi flexible filament. Much easier to print. A spool of 1.75mm filament it is about as flexible as a braided wire of the same thickness. But print it to be several layers or a few mm thick and it gets firm just like a lot of braided wire together gets hard to bend. That might work for you. I might also have some of that around if you want a sample.

The better option for ski bones might be Nylon. Nylon is really strong and soft to the touch but it is also difficult to print. You have to have a bed that can get really hot, a nozzle that can stay steady at 245. Not all printers can do that without taking damage. Then Nylon filament absorbs water from the air like a spong. That water boils as the filament is extruded causing a lot of bubbles in the extruded plastic. Really ruins the print. Nylon has to be kept in air tight containers with desiccant as much as possible. I have wasted a couple spools of Nylon. Nylon shrinks when it cools so it might warp during printing. And I might be remembering wrong but I think it is a bad idea to use it on PEI. Something like it will bond forever with the PEI and you will destroy the PEI getting it off. I could be remembering wrong.

So yeah… I guess I would suggest soft PLA.

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I print a ton of TPU on my Wanhao Di3 printers. I upgraded them to Flexion extruders, but printed TPU with the stock MK8 extruder with a lot of success. The trick to printing flexible material is to support it all the way through the filament path between the extruder gear and nozzle. If there’s a gap between the gear and cooling block where it can buckle, it will. Especially with the very flexible stuff like NinjaFlex (shore hardness 85A). You may can get away with “semi-flex” like Sainsmart or Hatchbox TPU (shore hardness 95A) if you go slow. If your extruder does have a gap after the gear, there’s probably a modification that can be printed. Search Thingiverse. This is the one I used on the stock Wanhao extruder before replacing it with the Flexion: https://www.thingiverse.com/thing:1340811