Printing flexible filament

Discussion in 'Calibration, Help, and Troubleshooting' started by Spoon Unit, Apr 24, 2016.

  1. Spoon Unit

    Spoon Unit Well-Known Member

    Joined:
    Sep 6, 2015
    Messages:
    1,095
    Likes Received:
    322
    Will happily take any advice on printing flexible filament.

    I bought some Rigid.Ink Flexible PLA. Totally bendy stuff on the reel, quite a departure from ABS/PLA/XT/PETG/nGen.

    For reference I tried printing 3 models so far, all with . All printing directly onto clean glass at 210 nozzle, 100 bed. So far, none of them have any lifting issues, but there's not models that would generate stresses. I'm trying to print tyres and belts just for the fun of getting some experience with flexible filament.

    One issue I did have was that my first tyre stopped printing at some point on about layer 3 and I looked up at the extruder to see a real mess. The filament had basically stopped being pushed into the tube down to the hot end and was just getting mushed up around the hobbed gear. I think this could have been the result of regular and rapid retraction just over stretching the filament in place. So I turned off retraction completely, which creates it's own issues, but I'm curious if other people found they needed to tweak retraction speed at all with flexibles.
     
  2. Sarah Nicholson

    Sarah Nicholson Well-Known Member

    Joined:
    Dec 20, 2015
    Messages:
    319
    Likes Received:
    114
    I turn off retraction completely when printing flexible stuff, but that's on my current printer which is a Bowden setup. I also turn the speed right down and the extrusion multiplier up a bit, +10% or so. My current extruder doesn't constrain the filament very well though so my current process is probably a bit extreme for the BigBox.

    For TPU I printed it around 200 and 40-50 bed, I found I didn't need the bed any hotter than that. Still not completely happy with the surface finish, so it's something I definitely want to perfect on the BB.
     
  3. Henry feldman

    Henry feldman Well-Known Member

    Joined:
    Sep 5, 2015
    Messages:
    969
    Likes Received:
    389
    I'll let you know @Spoon Unit since I have a big ninjaflex job (a simulated stretch of colon for a medical trainer) on the printer right now (well I hope I do - the first 3 attempts ended up with the filament shooting out of the side of the extruder in a big loop). The funny thing about it, is that is the first filament that has ever just dropped right through the extruder into the hot end! Anyway, I am printing at 230 with a lower speed. If it either works or fails, I'll get all the settings...
     
  4. Henry feldman

    Henry feldman Well-Known Member

    Joined:
    Sep 5, 2015
    Messages:
    969
    Likes Received:
    389
    OK, I'm giving up for a little while because I can't make 2 sequential calibration extrudes work (the 100mm to set the esteps). Filament starts coming out the front, wraps around things, badness ensues, words were said... Back to printing titan parts in Blueprint for a while... (which I at least now have Kevlar gloves to handle until they fully cool...)
     
  5. PsyVision

    PsyVision Moderator
    Staff Member

    Joined:
    Sep 4, 2015
    Messages:
    798
    Likes Received:
    248
    @Spoon Unit I printed with retractions on when using NInjaFlex, in fact, I didn't change them at all from the standard profile. Second, I printed slow, 20 or 25 mm/s in S3D with all the usual underspeeds. I put the temp a bit higher than recommended I think, maybe 240. Titan will print easier as the PTFE goes really far up to the hobbed bolt.
     
  6. Spoon Unit

    Spoon Unit Well-Known Member

    Joined:
    Sep 6, 2015
    Messages:
    1,095
    Likes Received:
    322
    Yeah - I can see why having the PTFE closer would help. 240 ! Wow. I did print 20mm on layer one, but then let it double on layer two. Did you stick with 20 for the entire job?
     
  7. Spoon Unit

    Spoon Unit Well-Known Member

    Joined:
    Sep 6, 2015
    Messages:
    1,095
    Likes Received:
    322
    lol


    Ahhh. You're printing the Titan parts in Blueprint huh. What made you choose that?
     
  8. PsyVision

    PsyVision Moderator
    Staff Member

    Joined:
    Sep 4, 2015
    Messages:
    798
    Likes Received:
    248
    Maybe not that high, it was a while ago, but higher than recommended. 20/25 the whole job
     
  9. Henry feldman

    Henry feldman Well-Known Member

    Joined:
    Sep 5, 2015
    Messages:
    969
    Likes Received:
    389
    Very high temperature resistance. That being said see my other post about the result the second time around...
     

Share This Page