Titan grinding through pla

Discussion in 'Calibration, Help, and Troubleshooting' started by npm1, Aug 6, 2017.

  1. Spoon Unit

    Spoon Unit Well-Known Member

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    Yep, I only recently wondered what the hell was suddenly causing layer shifts and realised it all came down (most likely) to there not being enough easy play in the cables from the top of the machine to the print head. This was a result of various upgrades combined with laziness for not properly re-tieing the cables to the spine.

    While 3d printing is by no means simple, I do find it very rewarding to have, diagnose, and fix issues. It's a fairly pure logical process, that just requires step by step analysis.
     
  2. kazik

    kazik Member

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    The funny thing is, after hours of troubleshooting, that probably the solution is very simple and just by the corner. And that’s why it is si frustrating ;-)
     
  3. Spoon Unit

    Spoon Unit Well-Known Member

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    Interesting looking thing Kazik. That's some print head :).

    So, dust suppression is clearly key for you. I also see the foam around the filament input to the box, presumably again to prevent any dust particles. The problem you're having doesn't seem to be about getting more filament, but about not being able to push that filament in. You're direct drive so there's no undue worries with retraction. You say you eventually have an issue even if you use zero retraction.

    So let's start with zero retraction.

    You say that short prints are fine, but longer ones create issues, which definitely speaks to a problem with cooling in the heatbreak. You have a standard fan blowing air over the heatbreak heatsink. Is that running at full speed, or have you slowed it at all? Are you feeding it with enough voltage? Basically it should be painfully noisy in it's current format if you have it a full speed, which is probably required.

    Are you in a coldish climate or a hot one? Do you have any temperature gauge on the inside of the enclosure to actually figure out how hot it gets in there? Are your extruder and drive motors hot to touch or cool? Heated bed?

    Start with PLA.

    To get a good first layer, the bed temperature you can use is totally dependent on the bed material. With BuildTak you can print cold. I use A PEI-coated ALU bed which I warm to 80 degrees for layer 1 and then cool to 65 for the remaining layers. If it gets lower than 55 the part can pop off. You know your bed better than me. Use the minimum temp you can get away for a good first layer and then cool the bed as far as possible so that the part isn't coming away.

    Create some test blocks for printing so that you can figure out how long it takes before failure occurs. You want one for 10 minutes, 20 minutes, 30 minutes etc.

    Once you know the point at which failure's about to occur, you can be in the vicinity and video the failure, take temperatures and so on. A simple thermometer in the enclosure would be a good start. Can you video the print with a clock and the thermometer in view?
     
  4. kazik

    kazik Member

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    Thanks for that reply. Tomorrow I’ll do more tests. I constructed this filament monitor to pause the print when filament stops moving. That gave me the info on the temps just before the failure. I was thinking about some rapid temp changes, but it is not a case.

    Filament is also running ok. When you look at the last picture of wasted filament pice, it clearly looks that grinding caused a problem with pushing, not pulling,

    Fan is moving in full speed and is noisy. I don’t care about the noise over there.

    Re. to extruder motor, it is hot. This is one of my concerns.

    I’m from Poland so it’s not too hot currently ;-).

    I’ll put the camera inside and we’ll see.

    In the meantime I’ll build the water cooling for my V6 from some garbage.
     
    #24 kazik, Feb 15, 2018
    Last edited: Feb 15, 2018
  5. Spoon Unit

    Spoon Unit Well-Known Member

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    All motors should really run pretty cool. If they're not, they're probably being supplied with too much juice. If you can alter that via your firmware, this would be another way to lower heat. Mine are all lukewarm even after hours of action, but no enclosure.
     
  6. mhe

    mhe Well-Known Member

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    I had a similar issue before where the hot end would clog up. Not only do you need to apply thermal grease between the heat break and the heatsink (E3D started to include that) but what really made my V6s super reliable in the end was applying a taper to the bowden tubing that goes inside the heat break.

    Since the heat break is tapered in the inside from the top, there will be a gap between the bowden tube and the heat break and this is where stuff accumulates every now and then. If you taper the end of the short piece of bowden tube (using a pencil sharpener works fine), then you eliminate this gap and have a smooth path for the filament that should become pretty much maintenance free.
     

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