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Rotated objects with supports look fine in Cura, but don't print bottom layers


Slashee_the_Cow
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Posted (edited) · Rotated objects with supports look fine in Cura, but don't print bottom layers

First off: sorry, I don't have Cura projects for these (I generally just slice it, save the gcode and quit Cura; screenshots are from recreating the process). Running version 5.4.0. Printing on a Creality Ender 3 v2 Neo (bit of a mouthful, anyone?)

Edit: Not sure if it matters, but just printing PLA with the default nozzle (0.4mm I think?). All of these are standard quality, the only thing I change from the default profile is adding the supports.

Edit #2: Just tried printing them on the side again, but moved then 1mm higher (obviously had to turn off "drop down"). I did get 1mm more of them, but sadly that's not quite all. Did save the Cura project for you though.

 

Hiya! So I'm trying to print this series of relaxed buttons:

image.thumb.png.634060f77374da08fa25c5fd3718b309.png

They need support, because the back of each one is in the air. First print went pretty well, I could basically take off the support with my hands:

image.thumb.jpeg.6c9d4b26014d17e731e1a686e1aad780.jpeg

Okay, yeah, a little rough around the edges, but good enough. For whatever reason, on the second print (same gcode file, printer on same settings) it was hard to get the support off, and for the third it was downright impossible. If someone could explain this phenomenon to me, that'd be great. To my untrained eyes Cura seemed to handle the support generation fine:image.thumb.png.28febcc2ac468de07072d94fbb319395.png

So I played around with the settings, reduced support density, a few things like that, and it was amazingly (or obviously, if I messed with the settings wrong) even more impossible to get the supports off. Then comes the lightbulb moment: if I print them on their side, there's a hell of a lot less that will need support! Cura didn't seem to have any trouble with the supports here:

image.thumb.png.26e90ac57f7dbb296aa33129d7b83d94.png

But when I printed it, well, let's just say I was a little flat about the results:

image.thumb.jpeg.e892b536f7c731f570e88ccf73156a21.jpeg

Then another lightbulb moment! If I print it more like stairs, it'll build more support, and the more there is, the easier to take it off, right? (And for the most part, yes it was)

image.thumb.png.db7d6364380291933ad3322bcdd510bb.png

Again, Cura seemed to have it covered pretty well. To the printing! And after the cleanup!

image.thumb.jpeg.da71be5644459734b739b511e8a9c02e.jpeg

Umm, I think that button on the end skipped chest day. At least this one is usable (until I break it).

 

So I'm stumped. Anyone have any idea why it'd be behaving like this? Also, anyone have any ideas how I can print it that will make taking all the supports off easy as button pie? I've attached the STL file... not sure there's much more I can offer to help you help me, but if there is, let me know!

 

Thanks!

ButtonSlide5.stl

CE3E3V2_ButtonSlide5_levitating.3mf

Edited by Slashee_the_Cow
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    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers

    Try to print it on an angel of 45°. See attached file.

     

    ButtonSlide5.thumb.PNG.806a0c30f6d5e8fb87f2a2ba08f0cd35.PNG

     

    In general, w/o having a project file no one can see which of your settings are wrong. It should be quite easy to save your project file with short cut  [strg]+[s] or -->file -->Save Project via menu. 🙂

     

     

    ButtonSlide5.3mf

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    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers

    I will grant you one thing: the supports at 45 degrees were pretty easy to remove (and this whole thing wouldn't be necessary if I could figure out why supports went from "easy to remove" to "destined to be permanent part of print" on the same file).

    But as for the result of your suggestion: it still flatbottomed.

    image.thumb.jpeg.3d53104340672e7e1596d6476b4e8489.jpeg

    FWIW: I know saving Cura projects is easy, I've just never had the need... load model, slice, save gcode, all done.

    But here's the file for this project, and I also updated my first post (see Edit #2 at top and attached file) with the project file from a different, slightly less unsuccessful print.

    CE3E3V2_ButtonSlide5_45.3mf

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    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers

    So based on my experiment in edit #2 of my first post, I moved the buttons up 4mm from the base instead of 1mm as I originally did. Result? Whole buttons, but there is not 4mm between the bottom of the buttons and the bottom of the support.

    image.thumb.jpeg.c10906cf19211ffd51c4f026616a0f75.jpeg

    CE3E3V2_ButtonSlide5-Levitate4.3mf

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    Posted (edited) · Rotated objects with supports look fine in Cura, but don't print bottom layers

    This looks like the first filament layers are printed too hot and there was no time for the filament to cooling down enough. Looking in your project file (CE3E3V2_ButtonSlide5_45) I see that your cooling is off for the first 4 layers. For normal prints this is ok but for your tiny print this will not work out well and the layer will melt and sagging downwards as you can see in your print. Try to start printing layer one with little fan involved (for good adhesion) ) and at layer two with 100%.

    For those kind of parts it is sometimes good to play a little bit with filament temperature and fan settings as printing time for such small areas is too short for cooling down the former printed layer. Sometimes it may also help to print a additional part parallel giving the layers more time to cool down for the next layer.

     

    Edit: This maybe as well happen with your last test

     

    Edit, one more:

    Take a look for support entries. There is a setting called "Fan speed overwrite"

    Edited by DivingDuck
    add comment for your last test print
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    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers

    So as an (un)scientific test (only change one variable at a time, people!), I printed another set just laying flat on the bed, with supports added (the kind which was working fine before, except I was having ever more trouble taking out the supports), but with it set so that cooling is off just for the first layer, then goes up to max. I'll try the fan speed override next.

    image.thumb.jpeg.93b0176806c2fbb5a2335bde74a4754e.jpeg

    Hey, what gives? You're not supposed to be flat!

     

    Possibly stupid questions:

    1. Should I raise (or maybe lower) the bed temperature? The default in Cura is 50 but the default in the printer is 60.
    2. Is it possible the Z offset on my printer is a little low and it's sort of compressing the lower layers or something?

    CE3E3V2_ButtonSlide5_Flat_FanAt2.3mf

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    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers

    Unscientific experiment #whatever I'm up to: Levitating 4mm from build plate (it's the only one I've been able to use!)

    Settings changed:

    • Reset Cura fan settings to normal. Then turned on fan speed override (which did make it not go from 0-100% at once while it was doing the supports).
    • Changed Z offset on printer from -2.40 to -2.35

    Results:

    image.thumb.jpeg.9820b192f687f22036e4de2b5ca6b5ad.jpeg

    Observations:

    • Definitely no better on the height front than the one I did last night.
    • Looking at that warping, I should probably get the build plate a bit warmer.
    • The bits where it looks like it's peeling up a bit from the bottom layer (highlighted in the yellow rectangles) might mean something, but I'm too new at this to know what.
    • Honestly? It does mostly look (to me) like Cura's preview, minus some intermediate layers, except that the print's bottom layer appears to extend a little bit past the rest, which it doesn't in the preview:
      image.thumb.png.a6041d3ba00fced5e6f0e09352b102c0.png

    Conclusions:

    I still have no idea what I'm doing. And I'm even more confused by it having only started recently when I'd been printing with the same settings for a day or two before (considering how not long ago I bought the thing, a significant part of its life - I'm not completely new to this, it's not my first printer)

    CE3E3V2_ButtonSlide5-Levitate4-FanSpeedOverride.3mf

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    Posted (edited) · Rotated objects with supports look fine in Cura, but don't print bottom layers

    Experiment the next: Use Creality's slicing software (going by version number, based on Cura 4.8.2)

    Trying to print the buttons rotated 90 degrees so on their side, but not moving it above the build plate. Default settings, other than increasing the infill from 10 to 20% and adding supports.

    Result:

    image.thumb.jpeg.474fd7ed12a7c746342d2559f26b0dfa.jpeg

    It didn't even $@#!ing adhere!

    Observations

    • Preview showed it trying to build a lot less support than Cura was on the same model, in the same conditions.
    • Seriously, it's their own software, based on Cura, and it fails even harder than Cura?

    CE3V2NEO_ButtonSlide5-CrealitySlicer.3mf

    Edited by Slashee_the_Cow
    Added more detail
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    • Solution
    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers

    I think you are having some printer problems.  That's a simple model and unless you use some bizarre combination of settings in Cura there shouldn't really be a problem.

    • Go over the printer and wiggle things.  Make sure all the fasteners are tight (including the hot end).  Double check that all the trolley wheels on each axis can just be turned by your fingers.  Too tight and an axis can drag and too loose makes "repeatability" tough.  The belts should "twang like the string on a bass guitar".  "Just because parts came assembled from the factory doesn't mean they were assembled correctly" - Me.
    • Bed adhesion is always a problem for people starting out.  The bed needs to be clean and an Isopropyl Alcohol wipe with a dust free cloth before you start printing can't hurt.  There are bed adhesion promoters available.  I use Aquanet Super Hold hairspray for PETG but I get away with just a clean bed for PLA.  I have the Creality glass bed on my Ender 3 Pro.
    • If your "Z-Offset" isn't sufficient then the gap for the first layer is too high and there isn't enough squish to insure the extrusions are stuck to the bed.  I level by hand and I run the "Initial Layer Flow" at 105% (just in case).
    • The maximum "Overhang Angle" for .20 layer height and .40 line width is 63°.  Set your Support Overhang Angle to 55° and there won't be as much support to remove.
    • You can dial down the "Support Interface Flow" in the Material settings.  I  generally run it at 90% for PLA, but that is printer specific and would require some experimenting.
    • Set the "Support Horizontal Expansion" to "0".  For large flat areas some horizontal expansion is good but when curves are resting on the interface then you can get some "stickage" where you don't want it.
    • Here I've set the model to 0.4 above the build plate.  I want some support interface under the part.  The "Support Interface Density" is 60% because I don't want the first layer of the part falling through the gaps.
    • You have your fan set to 100% so the override doesn't really do anything because you are already at full speed.

     

    image.thumb.png.5d24ff3a72f86006af17626e56449812.png

     

    I fool around writing post-processors.  I have one that will change the fan speed depending on the "feature" (skin, support, support-interface, walls, etc.) and another that does a drive-by pattern 1mm over the print with the fan on (no printing...just cooling).  The cooler the interface the easier it is to separate from the print.  Unfortunately, you are right at bed level so there is only so much you can do.

    If you want to play with those posts let me know and I'll put them up here.

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    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers

    You seem like just the printer sensei I need! Mind if I bother you with some (probably stupid) questions?

     

    18 hours ago, GregValiant said:

    Go over the printer and wiggle things.  Make sure all the fasteners are tight (including the hot end).  Double check that all the trolley wheels on each axis can just be turned by your fingers.

    How much turning are we talking about? The wheels on my Z-axis were probably a bit too tight, in that I couldn't move them at all. Could actually explain my "lower levels not going down right" problem. I loosened them to the point where I turn the wheel with my finger and it can rock the X-axis gantry up and down a little but not enough to make it move up or down and stay in place like I can by turning the screw.

     

    18 hours ago, GregValiant said:

    The belts should "twang like the string on a bass guitar".

    I've only got a regular guitar, but I know roughly the difference in twang. And tightening to correct it (on both X and Y axes) was one of the first things I did after printing didn't go as well as I was hoping.

     

    18 hours ago, GregValiant said:

    "Just because parts came assembled from the factory doesn't mean they were assembled correctly" - Me.

    Don't worry, me and the X-axis gantry that was off by about 4mm (not as huge as the videos I watched, but still plenty enough to cause problems) already figured that out. Thankfully I could fix it just by taking the top bar off, taking the gantry off, tightened a couple of screws, put it back on and it was good.

     

    18 hours ago, GregValiant said:

    Bed adhesion is always a problem for people starting out.  The bed needs to be clean and an Isopropyl Alcohol wipe with a dust free cloth before you start printing can't hurt.

    Well that last post was more about "lol Creality's own software produces g-code that doesn't adhere when Cura does". I haven't actually had to clean it yet (still a baby, in relative terms), just heat it up enough to get tiny ghosts of prints past scraped off with the scraper that comes with it. I'll try and remember that if I start having problems that don't want to be anything but problems.

     

    have used the "blue tape and scratch it up real good" method in the past, but... does anyone remember the New Matter Mod-t? Smooth plastic unheated plate = not ideal surface. I don't intend to try that with my Ender.

     

    18 hours ago, GregValiant said:

    If your "Z-Offset" isn't sufficient then the gap for the first layer is too high and there isn't enough squish to insure the extrusions are stuck to the bed.  I level by hand

    So.. when I was testing things while I was printing one time and a Z-offset of -2.34 wasn't adhering the skirt but -2.35 was means I should go lower?</sarcasm> I've also figured out how to tell it's too low (fun grinding sound when it travels over parts that have already been printed). Suggestions as to how much (and yes I'm sure it varies from printer to printer and probably hot end to hot end) would be welcome, something I read somewhere else the person said they used a feeler gauge with a 0.04mm blade when printing PLA. My attempts to repeat their results were somewhat incredibly unsuccessful.

     

    Most success I've had levelling (and seems fairly successful, crap, I just jinxed it) was a somewhat lengthy version of the printer paper > start in centre > go from corner to corner to corner until you don't have to adjust any of the corners > go back to the centre and do that again process.

     

    19 hours ago, GregValiant said:

    The maximum "Overhang Angle" for .20 layer height and .40 line width is 63°.  Set your Support Overhang Angle to 55° and there won't be as much support to remove.

    Is there some pretty maths behind this so I can make mistakes trying to figure it out for other heights and widths (never did trigonometry? (never did trigonometry)

     

    19 hours ago, GregValiant said:

    You have your fan set to 100% so the override doesn't really do anything because you are already at full speed.

    Well, it's not always at 100%... but I should probably change it from the default layer 1 = 0%, layer 2 and up = 100%.

     

    19 hours ago, GregValiant said:

    I fool around writing post-processors.  I have one that will change the fan speed depending on the "feature" (skin, support, support-interface, walls, etc.) and another that does a drive-by pattern 1mm over the print with the fan on (no printing...just cooling).  [...]

    If you want to play with those posts let me know and I'll put them up here.

    You betcha, I love cool tricks!

     

    Think that's it. Thanks for all the info! And thanks more if you reply to this!

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    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers

    You will need:

    1. A carpenter's square.
    2. A steel straightedge/ruler that is longer than the printer is wide.
    3. A Vernier or digital caliper would be good but isn't required.
    4. The correct wrenches to loosen and tighten fasteners on the printer.

    If the frame and axes aren't exactly square and parallel, your parts will be skewed and leveling can be off.  The frame needs to be calibrated to insure that everything is aligned correctly and movement is free but controlled.  As you found out with the X beam ... things can be off.

    Put the printer on a flat stable surface.  A heavy countertop will work.

    • The front faces of the Z uprights must be planar parallel.  Put the straightedge across them.  The screws come up from the bottom.  Make sure each upright is at exactly 90° to the "feet" that they mount to.  Use your Mark I eyeball and view from the side.  The Z uprights must rise parallel to each other.
    • The Y beam (that the carriage moves on) must be exactly parallel to the surface the printer is resting on.   The bottom cross-beam is attached by 8 screws (4 from each side) that are below the Z uprights.  Loosen those so you can rotate the cross-beam/Y beam assembly to adjust the angle of the Y beam exactly parallel to the surface the printer is on, and at 90° to the Z uprights.  Tighten it up.
    • The Y beam is bolted to the cross-beam by screws that come up from the bottom.  Loosen those and make sure that the Y beam is exactly 90° to the cross-beam.  That should also make it 90° to the X beam.
    • As you have found, it's a pain to adjust the X beam angle.  Once you have the "Y" squared up you can adjust the angle of the X beam so it is at 90° to the Z uprights.  There might be some up-down wiggle on the right end, but not much.
    • With the X beam at Z=0, adjust the 3 trolley wheels at each end.
    • Loosen the top cross-bar at one end (screws from the top) and move the X beam all the way up.  Tighten the top cross-bar.  Now the Z uprights are parallel.
    • With the Z back down to 0, measure the distance from the Z upright to the Z threaded rod just above the coupler.  (Make sure the couple does not drag on the Z motor housing.)
    • With the Z still at 0, measure the distance from the top of the Z upright to the top of the Z threaded rod just above the coupler.  It needs to be the same as the bottom measurement.  If it is not, the Z motor mount bracket needs to be shimmed.  Mine needed .012" (0.30mm) of shim.  This prevents "Z binding".
    • Calibrate the E steps and do NOT use a single/double wall "calibration" cube.  Just make sure that when you ask for 100mm of filament that exactly 100mm is pushed by the extruder.

    I'll go have another coffee while you do all of that.  Then we can talk software and how to program your 4 axis robot to get it to do what you want it to.

     

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    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers
    23 minutes ago, GregValiant said:

    I'll go have another coffee while you do all of that.  Then we can talk software and how to program your 4 axis robot to get it to do what you want it to.

    No rush. I don't have a carpenter's square and the nearest hardware store isn't open for another seven and a half hours.

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    Posted · Rotated objects with supports look fine in Cura, but don't print bottom layers

    Software means "Learning Curve".  I didn't think it was steep enough.  I went through all the Cura post-processors and tweaked them and I've added a few of my own designs.  I've figured out how to put in a pull request so who knows, a couple of these might make it into Cura.

     

    Unzip this one and put all the files into the Scripts folder within the Configuration Folder (use "Help | Show Configuration Folder" to locate it).  On my Windows machine it's:  "C:\Users\..user name...\AppData\Roaming\cura\5.4\scripts".

    Gregs Post Processors.zip

    In Cura use the "Extensions / Post Processing / Modify Gcode" command the "Select Script".  The top of the list should be the "Help" file.  When you select "Help" the PDF should open.  It contains descriptions of the post processors and settings for each.  If you don't unload it then the Help file will open every time you start Cura.  It gets annoying.

    "LittleUtilities" contains 7 separate post processors.  They are things I wrote in response to requests I've come across.

     

    This one is an "overwrite".  Unzip and put the single file into:  "C:\Program Files\UltiMaker Cura 5.4.0\share\cura\plugins\PostProcessingPlugin".  The change is that if you have any post-processors running the names get added to the gcode.

    PostProcessingPlugin.zip

     

    This is a "Windows Only" app and it's unsigned (I'm cheap) so you may have to fool your anti-virus if you decide to install it.  It's an interface (front end) between you and the printer.  It requires a USB connection.  When you unzip the file there is a readme text file.  It doesn't send Gcode via the USB but rather controls printing from the SD card.

    Greg's SD Print Tool

     

     

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