I think I have Bowden problems



  • @bluedust I'm curious what current you are using for the extruder. If you increase it to 85% of max rated does the behaviour improve at all?



  • @phaedrux

    I bought e3d steppers. 1.68A Phase.
    I had it at 1.2a and now just at 1a. can easily up to 1.4


  • administrators

    @bluedust said in I think I have Bowden problems:

    Still playing around with this...
    When I enable Pressure Advance at .1, my extruder is noisy and sounds like its ticking, as it looks like the stepper is fighting with itself, and the gears doesn't know which direction to go. Is this normal? or at least expected? It just sounds like the its going to have an early death.
    I backed it off to .6, and its a lot quieter, but still playing with this.

    It's normal for the extruder drive to move backwards a little at the end of a move when using pressure advance. Whether the extruder is noisy when it does this depends on how well the gears mesh.



  • I think all this trouble was caused by a bad stepper motor. Going to find out how the warranty works on it.



  • I had a bad bearing in my titan extruder. E3d and Filastruder were very helpful in troubleshooting and I received a new bearing + spares. I have heard how awesome their support was, and now can say its true first hand. Very happy. Well worth spending the extra money and getting brand name parts.
    And yes, I also appreciate all the help I have received on this forum with my DuetEth board. Calling out @dc42 for helping me many times in the short amount of time I have had my Duet board.

    I have also met Filament Friday and have been talking to the 3d Printing Professor for a few weeks now. Both very awesome people.
    A few more people/groups to call out.
    Roy and his V-King builders group.
    RatRig's builders group.
    CoreXY Facebook group.

    A mention to the Professors Low Poly Dinos! Very cool. Alot of work. Did I say very cool!? https://www.kickstarter.com/projects/3dpprofessor/low-poly-dinos-dinosaur-3d-models-by-3d-printing-p

    The 3d printing community has some pretty awesome people. I am happy to be apart of this community and hope to contribute in someway once I lose my noob status. I really do appreciate all the help I have received here and on other forums I have been apart of.

    You guys are awesome!



  • A free opinion and worth every penny:

    I am not a big fan of Titan extruders. I've slowly gotten rid of all my Titans in favor of Bondtech BMG.

    I do agree that E3D has fantastic service. That makes it doubly weird that they ignore the fundamental design flaw in the Titan (misalignment). It has been posted to their forums many times, and they always suggest the same fix (that doesn't actually fix it) and refuse to consider changing the design.

    See how the filament is not "in the valley" of the hob? Despite the metal piece being forced to the left of the plastic gear to the point you can see splines sticking out? That "move the metal in relation to the gear" is the suggested fix that doesn't really work. The misalignment was much worse prior to the suggested fix... but it is still not right.

    Also, if the filament DOES "move into the sweet spot", the diameter of the drive effectively changes, and extruder calibration goes out the window... unless it stays there while you calibrate... which it doesn't.

    0_1536810860676_IMG_1096 Crop.jpg

    .

    Anyway, enough of that... Try a Bondtech BMG.

    P.S. The BMG handles flex filaments just fine (the Titan doesn't claim to handle flex, and definitely doesn't in actual use). So even if you don't care about any of the stuff in my rant above... 🙂 consider the BMG for future, uh, "flex"-ability!



  • @dc42 said in I think I have Bowden problems:

    • Bowden systems need a retraction distance of around 8% 0.8% of the Bowden tube length plus 1mm. A little less using Capricorn tubing; a little more if you don't have clips under the collets. Tune the retraction by increasing it until the zits disappear.

    Fantastic! I'd been using "more retract on longer bowden" but it never occurred to me to figure out a percentage factor... I'm going to cross check with my "gut feel" settings.

    FANTASTIC. Thank you.

    • On a delta I use a little Z lift during retraction, on other printers I don't because it is slow and wears the Z leadscrew.

    Me too.



  • @danal The Titan gear alignment can certainly be fixed, but it is a pain, but once done it stays fixed.

    Before:
    0_1536820188417_FullSizeRender 2.jpg

    After:
    0_1536820209667_IMG_2694.JPG

    The black gear needs to be forceably slid down the drive shaft about a milimeter or so. Then the drive gear needs to be slid down the motor shaft correspondingly so that the black gear and drive gear are aligned again. The idler arm rides against the drive gear, and the filament path is inside the idler arm, so it will then line up with the center groove of the drive teeth. In addition to this, I've added three 1mm spacers onto the motor shaft on the heat sink side of the idler arm to keep it in alignment.

    It's an unfortunate amount of work to have to do to get decent performance out of such a pricey extruder, but when it works it does work well.

    It has other issues as well though. The bolt that goes through the black drive gear is way too easy to over tighten, which completely damages the bearings. Tighten it by finger tip only.

    0_1536820547867_IMG_2660.jpg

    I've bought a bag of replacement MR95ZZ bearings just in case.



  • My titan extruder is currently mounted in a way that makes it hard to get a really good picture. Saying that, it doesn't appear I have the same problem you guys do.0_1536880304091_IMG_20180913_171535~2.jpg



  • @bluedust said in I think I have Bowden problems:

    My titan extruder is currently mounted in a way that makes it hard to get a really good picture. Saying that, it doesn't appear I have the same problem you guys do.!

    Yes, that looks pretty good!

    If a Titan self-aligned like that, I'd be happy enough with them to use them in most places. In fact, I've found that some of the Titan clones actually work fine, because they don't suffer the alignment problem. Very nice that that one is aligned and works fine.

    If aligned, the only difference then would be Bondtech BMGs vastly superior ability to feed flex filaments.



  • After I read everyone's comments, I took apart the extruder a few times, and messed with it a bit to see what I would get...

    • The large plastic gear pushes on the arm...
    • The Gear that is attached to the motor 'can' push on the arm if it is just sticking out past the large plastic gear or even if it is lined up evenly with the plastic gear, it will make the filament alignment worse.
    • The bowden tube used to align the filament on its way into the extruder is better positioned (very slightly) if a capricorn tube is used.

    I am not daring enough to push the extruder gear a meer half mm further into the large plastic gear to make the problem, if not go away, at least not be an actual issue to worry about.

    I also took a more accurate picture if my extruder.
    0_1537071357759_IMG_20180916_000635~2.jpg



  • @bluedust that alignment doesn't look bad at all. When you had it apart did you notice and oil on the bearings? Or rust?



  • I saw a small amount of oil, but no rust.
    I just bought this Titan Extruder. Well after the weird rust/failure issues that occured. Weren't those issues resolved last year?



  • @bluedust yes the new bearings should be in place. However as I mentioned above the bolt that goes through the black gear is very easy to over tighten and damage the bearings. Even slight over tightening is enough to crack the seal on the bearing and eventually the lube will leak out and the bearing will seize. Symptoms can be hard to pin down but under extrusion or odd surface textures can result.

    Just something to be aware of.



  • @Phaedrux
    Yeah. Thanks. I did have this issue with the original bearing, and when I finally found it, the bearing was in pieces. I wasn't thinking about the bearing being sealed and an oil leak would a first sign of failure. I have a few spares now and as such, would be the first place to look for any unexplainable problems recurring.
    Thanks for the tip.


 

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