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Posts posted by pavelr

  1. Hi Ultimaker & Community. So, to put it simply, two of my UM3 printers' quality is not what it used to be. They have both done their fair share of heavy printing, one of them non-stop for years. They still produce nicely looking models but not as a new one out of the box. Let's talk about bringing it back to perfection, after all, motor steps do not rust. 


    The natural though is to replace several parts, one by one, while printing the calibration cubes in between. My question is, what would be the right order - from most important to least important. 


    I hope this list of parts to replace is complete - or sufficient to bring it back. Please add more, and advise about what's most likely causing degradation:


    - Linear bearings LMK6 and LMKW6  (which already started making noise)

    - Long belts

    - Short belts

    - Bowden tubes

    - The nozzles

    - Rod holders

    Have I forgotten anything?

  2. I would be happy to see "one at a time" not only for distinct models, but for a model that splits into distinct parts above certain height. currently my only way to do this without having the head jump back and forth is write gcode manually. 

    Attached is an example of a part, and the gcode I did manually.


    Also - same way that there's a "gantry height", it could be great if Cura could be better aware of the head shape. For example, two pieces that are 2cm apart could at least benefit from several layers (up to the nozzle height) done before travelling. This would save a lot of time, energy and oozing.



    tile - thicker alternative 5mm.stl tiles manual slicing COMBO.gcode

  3. That's a better idea; I am missing the setting in Cura which was in the older versions, "material diameter", I do not know why they took it out. Personally I do not do what you suggest because having no hardware changes enables me to switch the spools frequently, so I avoid going to profile configs.

  4. Folks, I am getting good results by putting 1.75 into UM3 "as is" (no changes to the machine). This is what I am doing:


    1. Temperature 215. (this is becuase the feeder has weaker grip on the filament. Make it easy for the feeder)

    2. Layer height no more than 0.1mm on 0.4 head. On 0.8 head I allow myself to go higher (up to 0.4). With 0.25 I would not do it at all. (this is because you really want slower feeding). Decreasing print speed also works.
    3. Use better filament holder, with thin axis and a silicon lube spray will not hurt. I designed my own: https://www.thingiverse.com/thing:4354166 . This will help the spool roll, further reducing the required feeding force.

    4. In CURA, feeding rate set to 265% (which is, of course, diameter ratio squared).

    5.  Do yourself a favor and watch first 2-3 layers.

    6. Same feeder, same PTFE tube, same print cores. No changes to the ultimaker. It just works. 


    With right settings I have no "feeder slips". However, they might be happening without me noticing, so maybe you should refrain from that from big high-quality prints. But honestly, I am getting perfect results even on fairly complex prints.

  5. Guys, some comments here are incorrect. LOWERING the bed temperature actually helps very often.


    Try this: 60C initial layer, 50C subsequent layers. What lowering temperature does is this. It does not improve the "adhesive" properties of the material (actually makes it worse), BUT, it makes the bottom part more rigid on it's own. This helps reduce warping IN CERTAIN TYPES OF MODEL geometries, e.g. with corners.

    If you increased bed temperature and warping got worse - try decreasing. You may be surprised. 

    Also, increasing print speed is known to reduce warping in some cases.

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