Flexible filaments

The filament I'm considering on Amazon says its TPU, is that standard for flexible filament or what? Has anyone used this?

 

Tried some Ninja flex with my E3D V6 yesterday i have the tube going all the way up to the drive wheel.. i got it to feed, but it was massively under-extruding I was printing with ABS settings like they reccomended... tried to adjust it and then couldn't get it to feed anymore and gave up.

 

Perfect idea, it solved my extrusion problems with even Ninja Flex Semi.

I just found a pen with a suitable ink cartridge and used acetone to clean the ink out.

 

Thanks for the tips guys. I just got my filament in last night, so I'm about to try my first print today. I got it from amazon, its SainSmart TPU. The only two types I saw were TPU and TPE (less common), and from what Ive read online, the TPU seems to be what most people use.

I was under the impression that people were cutting their tubing short and the entire thing went down into the assembly, I didn't realize it was supposed to stick out the top like that picture posted above. Then again, I guess thats the point of having the drilled hole.

Over the past few months I've noticed the "E3D" comes up a lot in conversation. Is that an aftermarket hotend? What do I have stock on my ROBO 3D R1, bought (7.11.15)?

 

One more thing, don't I have to turn off retraction? Im assuming if it tried to retract, its going to pull the tube out? This particular part that I'm about to print, won't need to retract anyway, its basically a tube, or hollowed cylinder.

Also, multiple people under the amazon reviews state their temps for good prints were about 220C (Extruder) and 40-70C (Bed temp) what do you think? And Ive been using Kapton tape and/or hairspray for adhesion, is that adequate for flexible TPU?

 

Ahhh ok that makes sense, thanks for the info. My brother had bought me about 8-10 sheets (8x8) for my bday since he knew i just got my printer, and when i put the first one on (pain in the butt) EVERYTHING would stick without any other adhesive period, just the tape. And it stuck better than hairspray or glue sticks. The sheet seemed to work for quite a while, and the only reason i put a new one is because I tore it up with the scraper, getting pieces off the bed. The second sheet I put on had almost no adhesion whatsoever, and I'm wondering if its because i used a recommended "wet method" of applying it with window cleaner underneath as a lubricant, and then squeegie'ing the liquid out. It made tremendously easier to apply the tape, but absolutely nothing would stick to it, night and day from the first time i used it.

 

Ok, so almost exactly halfway through my print, my laptop went to sleep... I normally set it to 'never' sleep when I start a print, but I forgot and came back an the extruder was sitting there melting a huge blob onto one side, so now I have to start over, BUT it printed great for my first try! I don't know how flexible NinjaFlex is since this is the first flex filament I've ever tried, but it printed almost exactly as PLA does when it comes to definition. It didn't get stuck or anything, and the settings all seemed to work well.

It has more of a plasticky feel to the surface versus a rubbery feel, which concerns me since the purpose using a flexible material for me was to have something that has more friction. I wanted it to come out more like the texture of a rubber band. This SainSmart material flexes, but it doesn't really stretch, which is most important to this project, I need my print to stretch over a cylinder, and then have enough friction to 'not' spin around the cylinder when rotational force is applied to the print.

Is NinjaFlex more rubbery? Is there another brand that might be more 'sticky' after printed?

 

Ok, but what is the surface texture like of the semi flex? I want to be sure if i were to buy another spool, that I get the right one this time. Will the semi flex be rubbery to the touch so that it creates plenty of friction if you were to rub it against another rubber surface or a plastic surface? Or should I just go for the NinjaFlex, because the SainSmart is very flexible, just not stretchy, and its really more on the plasticky side. Id rather not have two spools of similar material.

 

Thanks yea it looked like little blobs. I was at 225 or 230. I'm having a hard time getting normal filament into the PTFE tube on my e3d anyway. I think i mushed the end when i cut it.. anyway i need to pull it apart and check it out because I havn't been able to get the Ninja flex into the tube since my first attempt.

 

I went ahead and just bought some NinjaFlex. Whats a good way to purge the hotend of old filament? This time its PLA. I saw somewhere, a suggestion to semi-heat the extruder to where the filament is not melted, but warm enough to pull it out the top and it would remove the entire amount stuck down in there. It looked easy in the video I watched, but I haven't gotten it to work that easily yet. I don't remember what temp was used, so I tried about 130, and it seemed to be a tad too warm. Is there another way to more easily get all the material out before loading a new material? When I swap from PLA to ABS I haven't had to worry about it because those are both hard materials and I just push it all out with the next filament, but loading NinjaFlex, it doesn't want to push out the PLA very well even with the little tube installed to guide the filament in.

 

Ok, so my print started out great, theeennnn it went downhill from there....If you notice, the bottom half of the print looks nice and smooth, then at that halfway point it just got sloppy from there as if it was having a hard time fusing together. You can even see small holes all throughout the bad half. Is it just because its so flexible that the higher it goes, the more it pushes around the part? i used 220C - 30C - 40mm/s. Is that too fast maybe? Im going to try 25mm/s next.