Rapidly losing faith in the Titan Aero :(

Discussion in 'Calibration, Help, and Troubleshooting' started by PuGZoR, Jan 2, 2018.

  1. PuGZoR

    PuGZoR Member

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    Hi all,

    I'm really hoping someone can help, because I'm super frustrated and quickly getting the impression that Chinese clones are pretty much the way to go from now on.

    I've finished calibrating and for the most part I'm pretty happy with the quality. It's quiet and when it's printing well it produces some of the best layers I've seen. Using eSun PETG on a Hypercube Evolution at 245°C nozzle temp and 85°C bed temp (straight glass, no glue). Retraction is at 1.5mm if I recall correctly and movement is quite conservative - 53mm/sec printing, 160mm/sec travel, outline 50% underspeed, retraction 60mm/sec, and retraction vertical lift a mere 0.3mm. 0.2mm layer height and slicing using Simplify3D. Printing from a Duet WiFi.

    Problem being that I can't print with it for more than half an hour without somewhat of a jam happening. It's not a 'hard' jam either - it sometimes clears up.

    I've attached a pic of the Polymaker PolyPearl Tower Torture Test that I've been trying to get a successful print on. It's quite small at only 99mm high and features a lot of challenging geometry.

    The lowest arrow on this shows the first few layers it happened on. Hard to see but there's two layers which had issues, but there were three or four layers between them which printed fine. The small inner struts in the pic show this too (it didn't just affect the one closest to the arrow - almost all artifacts on that layer were affected.

    Second arrow from the bottom shows a completely failed layer. This one failed so hard that when that ball on the top happened, and I killed the print, it took everything from that line above with it! Holding it together with my fingers for the picture.

    After that it starts getting real sketchy. The middle arrow shows a mildly-failing layer, but the second arrow from the top shows it really went downhill for a number of layers. I'm assuming the balling at the top was part failure or could have had something to do with the geometry it was trying to print.

    Only other clues I can give is that a clicking occurs.

    Things I have checked:
    - Top right hand screw that holds in the bearings and hob is on only very loosely (just tight enough to not come undone, with anti-vibration washers). Learnt this early on that it can make things skip!
    - Big and little gears are flush on the side that faces the heatsink.
    - PTFE tubing (meant to be 23mm) is slightly too short. I did have it slightly too long originally and it jammed things up.
    - Filament does indeed seem to be going close to the centre of the hob. Wouldn't say it's dead centre but it's close.
    - Not sure on the best pressure to apply to the filament for printing but it seems adequate. Possibly I could have too much? I'm not sure... Could this be possible?

    So I have done a fair bit of troubleshooting now and could probably assemble and disassemble a Titan Aero blindfolded.

    Please, someone help me!
     

    Attached Files:

  2. Old_Tafr

    Old_Tafr Well-Known Member

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    I think you need to isolate the different problems as I don't think there is a one size fits all, silver bullet.

    It may be better to sort out the jamming when not printing such a complex part as the complex part may well need various parameters tweeking in S3D, hit and miss if you get all these right in one go.

    I'm not saying that a setting in S3D is making your Titan Aero jam, I guess there is a possibility of this, but with several different problems printing a complex part means you have to sort out all the problem in one go to make a good print.

    Printing something really really simple with as many known parameters as possible is a good start. The fact that you have moved from a clone? that works to a different hot end assembly with I assume has different sensors and heaters? means that the previous parameters, not just nozzle and bed temperature may not be relevant to the Titan.

    It's a typical back to basics.

    There are plenty of posts here on Titan's "clicking" An exercise to eliminate this, possibly a mechanical problem would seem to be a good way to start as this is likely to affect everything you do and it almost certain to be inconsistent so causing a problem at different places so that printing the same part over and over again will give different faults and at different places. I doubt that the clicking starts at exactly five minutes ten seconds into the same print every time?

    Look for the E3D WiKi for the Titan Aero assembly instructions (follow them to the letter regardless of if your own experience suggests otherwise) maybe get someone else to go through with you as often people make the same mistake every single time they do something. If you really have a problem with the instructions create a post here/ Email E3D support about it.

    Look through all the posts on clicking and see if this reveals anything. Print something really really simple until this is sorted.

    Contact E3D support and ask them about the Titan assembly e3D Support <support@e3d-online.com>

    Try a solid cube of a few cm size and say a cm high

    Try a cube shape with walls 5mm thick

    Try a round pillar with a hole down the middle (sometimes called a tube ! :)

    As you succeed try more complex things.

    etc.

    If you change one thing at a time on a very complex problem you will end up making dozens of test prints, and go slowly mad.

    If you change two or three or four things every time you make a test print you will never know which change fixed things, if it actually does fix anything.
     
  3. elmoret

    elmoret Administrator

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    Are the bearings rotating freely? What motor are you using? How much current?
     
  4. PuGZoR

    PuGZoR Member

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    @Old_Tafr - to answer some of your suggestions...

    I've tried printing a few models and the problem comes up in different areas. For example, I tried the tower again last night and the issue came up during the base where it's very simple geometry (just plain old circles). It's an intermittent problem and I can't see a pattern.

    I've built a few printers now and I'm used to changing one thing at a time and seeing if it works. My first delta was a nightmare because I had so much wrong with it that when I did fix an issue a problem would still exist for another reason.

    When installing I followed the instructions on the Dozuki pages to the letter. Actually noticed it skips a bit which mentions how to install the idler lever... but I digress. I conducted new PID tuning too because I was using a Bowden setup with a V6 clone which would obviously have very different thermal properties.

    Unfortunately all the posts I've read about the 'clicking' issue seem to be related to a consistent issue rather than something as intermittent as what I'm experiencing.

    There's a good chance I've missed something very obvious but I think I've done a lot of leg work before posting here.

    @elmoret - I actually went back and retested the bearings last night. They don't appear to be seized or similar. They seem to be rolling well. I'm using the genuine slimline that comes bundled with it (think it's the 12.7N-cm ) These are rated at 1.4A aren't they? That's what I'm feeding them in the Duet config (since the drivers can handle up to 3A if well ventilated).
     
  5. dc42

    dc42 Well-Known Member

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    If you run a motor at its full rated current, it will get very hot. I remember reading posts from a user who was having extrusion problems, which turned out to be because the heat from the motor was softening the filament too much as it went past the hobbed shaft, causing the shaft to lose its grip. So I suggest you check the temperature of the motor, and if it is hot, turn the current down. My own Titan (non Aero) has a 1.33A motor which I run at 800mA. But its torque at rated current is higher than yours, around 22Ncm.
     
  6. PuGZoR

    PuGZoR Member

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    Thanks David, hadn't tried that yet. I'll config it down to 1.0A and see if it improves things and still manages to extrude. Since it's only intermittently happening even 1.2A might even be enough to get rid of the issue without losing too much torque.
     
  7. PuGZoR

    PuGZoR Member

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    I've torn it down three times tonight (including one failed print) and have the following observations:
    • I turned down the stepper to 1.2A and it didn't have any effect on the print quality. Jam/skipping/etc still occurred. Touching the motor while printing it wasn't terribly hot... my guess about 45°C. Warm to the touch but easy to keep skin contact with.
    • After removing the filament and extruding at operating temperature there was still something noticeably giving resistance. Couldn't get it to 'click' but something wasn't happy. Some kind of higher frequency issue but not as high as a fan would sound.

    Even though the bearings seemed to be in good condition I decided to check them again - have triple checked everything else so might as well keep rechecking until I find something wrong!

    Would someone be able to verify if this sounds normal?
    1. Although not seized the bearing which sits on the Titan Aero body doesn't spin terribly freely. It's actually quite squeaky now. It definitely wasn't squeaky when I first got the Titan Aero.
    2. The bearing which sits within the heatsink is hard to do a thorough inspection on due to being quite tightly placed and difficult to remove without damaging. I did notice though that when placing the large gear (with the hob) into this and trying to spin, even the slightest amount of being perfectly perpendicular to the bearing causes a significant amount of friction and makes it difficult to move.
    Could either of these issues be the cause for symptoms with my printing? I can't explain why it would be intermittent but it would explain why I'm seeing issues under a variety of circumstances (ie, without filament loaded).

    Thanks.
     
  8. Old_Tafr

    Old_Tafr Well-Known Member

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    If possible a few pictures of the Aero showing the bearings in question would be good.

    Bearings related to moving filament I would suspect can live with some slight resistance given how strong these stepper motors are. But once a bearing gets rough the amount of resistance varies enormously and will be random. Rotate any bad bearing to find out how it will move then suddenly almost seize.

    When you consider the numerous actions, printing at different speeds at different stages of a print, retractions etc. then add all these to possible random resistance of a bearing, you get an infinitely variable output.

    You changed from a working? clone of the Aero (Why? :) ) did this print the test piece ok, or was it only after changed to the real-thing that you needed to?

    I like the possibility that a motor was too hot, missing steps etc. Same could apply to a loose connection on the frame affecting any one of the axis's. The BigBox without a support across the front means that the (moving ! ) X assembly becomes the front support and can come loose at either end.
     
  9. steve87

    steve87 New Member

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    Hi Pugzor, I'm in the same boat: intermittent skipping on my Titan Aero. Also, my printer is a Hypercube Evolution controlled by a Duet wifi.

    My Titan Aero worked perfectly for the first couple hours of operation, but then the large gear would randomly bind up. I finally discovered that the bearing on the heatsink side had seized. Even with the seized bearing, my large gear can still rotate freely by hand but any slight lateral pressure on the gear will stop it dead in its tracks. I ordered a new bearing from the Filastruder store (didn't receive it yet).

    At one point, I noticed that my four main body screws were loose - that possibly caused the bearing failure. I also noticed that the screw which runs through the large gear can be tightened too much and cause friction - maybe bearing damage too.
     

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