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kinginnovator

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Posts posted by kinginnovator

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    1 hour ago, gr5 said:

    You could just edit out those tiny movements circled above by hand and see if that helps.

     

    Are you using Marlin?  What firmware are you using?  I think at this point i would recommend you get klipper firmware.  This will require hardware changes but it's worth it.  Klipper is about 10 years more modern than Marlin.  I guess the more important part is that it is a complete rewrite so it will have different bugs than Marlin and the guy who wrote Klipper is pretty damn smart and made very different choices (software architecture choices).

     

    The people who wrote marlin are also very smart but it runs on a very weak processor.  They made some tough choices to get it to work on an arduino.  Klipper doesn't have cpu restrictions and so the code is less likely to be buggy and it can handle weird gcodes better.

     

    Your issues are slightly more likely to be in travel moves (blue lines) than in extruding moves because travel moves are usually faster.  Moves this short with acceleration so slow *shouldn't* move any faster but... there are a few bugs in marlin where it violates acceleration limits. 

     

    Did you know there are two (two!) different max accelerations in Marlin?  One is meant to be *the* acceleration in every move - it tries to always accel and deccel at that rate.  The other is a "max accel" which I think is double which Marlin stays under in special circumstances.  It's a big kluge.  A hack.  It's ugly.  I forget what circumstance might make it go over the acceleration.

    Edit out those tiny movements?  Like in the g code? 

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    54 minutes ago, GregValiant said:

    I'm going to focus on the mechanical.

    If you print a taller model...does the skew move back (lessen)?, does it stop moving and then continue straight up(?), or does the skew continue to increase at a constant rate/angle?

     

    There is a lot of weight there and it's a pendulum.  I'm thinking maybe the bearing footprint of the X beam and print head isn't sufficient.  One mm of "offage" at the nozzle might be because of hundredths of a degree of rotation at the slide bearings.

     

    The wider the footprint of those bearings, the less the deflection will be.  You won't get perfect rigidity, but you need to strive for it.

    printhead marked.jpg

    This is an older picture.  We got rid of the slide bearings in the x,y and have gone to a track bearing setup.. lighter and much simpler.. if I can control the skew this eliminates alot.. In theory it shouldn't be mechanical.. I can print a single line tube 4 inches with no skew repeatable. I just might try klipper too at this point if I'm able to... we'll see... going to dive into everything today and even try an older version of Cura possibly... 

     

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    55 minutes ago, Torgeir said:

    Hi @kinginnovator,

     

    I'll see you're using Cura 5.3.1, the "new" Arachne engine. Have you ever tried the old slicer like Cura 4.13.1? This is the last stable version of the old Cura as far as I know (well it's a version 4.13.2 enterprise version).

     

    The old version is more predictable for various reasons. There are fewer small corrections/movements that can benefit your printer.

     

    In your printer definition setting there is only one 3mm filament, I assume you fix all this in the firmware.

    You are using 900mm for X/Y, so how many steps/mm? Of course, since the Z height is 1000mm, how many steps/mm here? It's a bit hard to understand your problem without these numbers.

     

    Thanks

    Torgeir

     

     

     

    I will definitely try this! Very possible it could be tiny changes from the older version! Thanks 👌 

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    55 minutes ago, gr5 said:

    I still think you should also mark your servo shafts and your couplers with a tiny mark using a sharpie to be *absolutely sure* nothing is slipping!  This is a very very common problem that people deny exists until they are shown proof.

     

    The set screws go into a pre drilled hole guaranteeing no slippage..  

    • Heart 1

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    I've tried everything... No luck.. Please see list of true's below:

     

    1. I can control the direction of the skew based on seam location.

     

    2. If I choose random seam the skew goes away but I suspect every layer will be a bit off from the previous.

     

    3. I can print a single wall/path line to any geometry without any skewing.

     

    4. I can print a single layer perfectly over and over and over and over..

     

    All the truths above are the bounding box to solving this pandora of fun!!! I have acceleration set to 80mm/sec super slow. I've tried higher accelerations with the exact same results. I've turned off jerk movement and also tried with it on. Wipe distance has been (0).. Most everything has been set to (0)..  GR5 said this " Or sometimes it's on a z move possibly.  Particularly buggy is if you move Z and another axis at the same time as the original programmers didn't expect this.  But cura probably won't do this anyway.  But it could be moves just before or after the layer change." This could be it????  My gut tells me it's happening at this moment of movement (see picture again)... This is the only thing I can think of that's different than printing a single layer line/path only.. Btw yes If I print spiral the problem should go away but that is not a solution to the actual problem that will effect all prints hear forward.... 

    layer change.png

    small test ring.3mf

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    Okay finally getting somewhere! I printed a test ring (double path wall). By manually choosing the seam location (front,back and right ) in 3 different prints I can control the direction of the skew (see picture). I also made a short video. I've also included the gcode and cura file. I think that it's actually printing perfect layers but something is shorting the distance most likely when it starts a new layer at the seam location when it tries to make a tiny quick movement to start the new layers outer path. This could be do to the inertia within a larger system like this not being able to correctly respond to such a tiny movement. What are your thoughts on this? Is there a way to compensate for all tiny movements as such or atleast alter the gcode to compensate? All ideas are welcome.. 

     

    https://photos.app.goo.gl/AE3CrfcWjPtKfzah8

     

    skew prints.jpg

    CFFFP_small ring.gcode CFFFP_small ring.3mf

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    43 minutes ago, gr5 said:

    Instead of playing with the shape of the part.  go to PREVIEW mode in cura and use the horizontal (not vertical) scroll bar to play through a few layers.  Maybe also set PREVIEW mode to show the speed setting as a color.  THIS is where you will see something non-symmetrical.  Some "weird" move that doesn't happen very often.  If you can find the movement that causes you to lose a step then this gives you a huge hint.

     

    I've personally done exactly this.  It's usually in the infill or travel moves among the infill or within "combing" moves within the infill.  It's usually not the outer shell (outer walls) lines.  Or sometimes it's on a z move possibly.  Particularly buggy is if you move Z and another axis at the same time as the original programmers didn't expect this.  But cura probably won't do this anyway.  But it could be moves just before or after the layer change.

    This is a great idea! I will do this tomorrow for sure to 'see into' what could possibly be causing this.... It makes zero sense if I can print perfect circles and walls in both directions but then have skewing happen on more complex shapes.. I know this will take time to figure out... My hunch is something that normally would work fine for a smaller printer (much less inertia) is hidden in the code and was never meant for something this large. I know that when I select randomize for the z seam this appears to solve everything via randomizing each layers start and stop locations and gives an overall average on the layers with everything working out in the end.. But I really need to pin point this because it's driving me crazy to have come so far yet have this happen at this time.. It's very expensive to build such a machine.. I really appreciate your ideas, knowledge and caring of my current situation and It will not go unnoticed!  

    • Like 1

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    5 hours ago, Torgeir said:

    Hi @kinginnovator

     

    As I'm looking into your printer, the extruder has a double feeder a'la Bondtech with only one stepper driving both feeders right above the extruder, right? Further the cold side of the upper part of the extruder is of water/liquid type.
    Then we'll see the two "heaters" connected to each side of the Y connector supplying the nozzle.

     

    This is a "huge" printer based on Ultimaker gantries, -so I wonder what kind of steppers are you using here? Also, -what kind of main board etc.?

     

    Edit; This is a really nice way to change / improve things the way you want!

     

    Thanks
    Torgeir

    Hey thanks! Its actually fed by a flexible shaft drive cable from an external stepper (nema 24). The shaft has a worm gear at the end that drive both Bondtechs simultaneously. This allows for some seriously high flows (as much as or more than a pellet system). Yes 2 heaters each 400watt potential.. This is all designed to achieve more that what's ever needed lol..

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted · Edited by kinginnovator

    Ok.... So I printed the same part at 45 and both sides skewed this time not a single side. This makes sense because they share the same direction. But I noticed in the firmware where the stop/start lines are at each layer change and I've been following a hunch. So I set z seam to random instead of shortest path and the skewing went away... So I decided to see if I could investigate further on this by printing a very long wall in both the X and Y direction (picture). No skewing took place in either to my surprise.. At this point there is definitely something different happening about the program in how it sees a more complicated geometry.  Yes you mention the layers of complications going on behind the scenes yes. I need to figure out a geometry that can point the finger at the monkey aka (demon lol) hiding. The last wall part had no travel moves or possibly so much else when compared to the square frame.. Any ideas on what time of geometry I could use to say "ah ha!" I use Fusion 360.. Ive owned 8 other (small) printers before this one so I definitely think I could be dealing with a very tiny demon where acceleration isn't the same in a smaller machine when scaled to this. There has to be some geometric shape I could print to test the next step.. Remember when I when to random Z seam everything went away and this makes total sense if the same layer isn't repeated electrically/mechanically.. 

    long wall.jpg

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    Thanks for responding.. I'm extremely aware of mechanical skewing. This is not it.. I can print a perfect cylinder over and over and over without any problems. I'm pretty sure if I orientate the part 45 it would go away based on the x,y moving at the same rate just like in a circle they would.  The problem is specific to movements based on geometry and how cura does the paths. I do believe there is a possible problem with acceleration somewhere and steps being lost or gained. My acceleration is set to it's lowest 80mm/sec.. I bet if I print a square part without that center geometry and just a frame it will print perfect. I will try this and get back to you. Jerk is off because I can print perfect cylinders..  How would changing layers be related to acceleration? After a layer change does it do something special in it's acceleration? What do you mean also by central bar where cura does 2X?  I've limited my acceleration withing cura to be around 120 for travels. I will print this at a 45 and see what happens. Will send pics shortly.  

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    Here is another tough one to solve.. I'm somehow gaining movement in one direction which is causing skewing. I can print a perfect cylinder with no skew. But when I print that test part (square frame) I get a predictable skew based on the parts orientation. Obviously this eliminates all mechanical scenarios based on the ultimakers symmetrical design. I'm predicting some sort of movement within the program that is causing this. The ring is a perfect symmetrical print that does not have the start/stop wall features of the square frame.  The square frame has a  symmetrical design also just start/stop walls. But what could cause this skew based on path movement? 

    Comparison.jpg

    skew angle.jpg

    Perfect ring.jpg

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    I can certainly try this.. I appreciate all your help here so much!! I wonder how fast this could react after a stop or end to a line path before starting a new line. I also wonder if I could adjust acceleration at the beginning 🤔  bit one for a split second while the extruder independently turns on and does not adjust itself relative to acceleration and speed? Just ideas.. if I get results from what you say I should try I will certainly let you all know.. This could also be part of a future problem to solve do to how much faster one could print with the idea of having more pre-melt on demand within the potential volume of a heated housing... 🤔 

    • Like 1

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    gr5 and GregValient,  I turned off retraction for this very problem because when you are extruding so much more material (think 10X the volume within the extruder heated pathway)  retraction is pointless at this point if you want to print 10X faster with so much more material. It is actually very responsive to not extruding when the extruder does not move. This type of setup would be similar to a pellet system. Or a Bowden that is 10X less responsive. Is there a way to not shut off the extruder completely in between stop/start moves,  like 1/2 movement or speed? I think this would definitely solve this. 

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    15 hours ago, GregValiant said:

    I think you just took the lead from "Godzilla".  That bad boy is pellet fed.  With your dual 3mm lines I'd guess you can retract.  From what I've gathered, that isn't easy on a pellet fed machine.

     

    If you'd like you can post a Cura 3mf project file ("File | Save Project").  I'll take a look and I'm sure there are others here whose curiosity would be peaked enough to attempt to troubleshoot the "Practice Layer" problem.

    Here is a link to the video. Let me know if your able to view it. Flex drive setup on a worm gear. It's possible it could be trying to infill into tiny areas? Don't know... 90 percent infill because I tried 100 percent to try an eliminate such tiny movements instead of long continuous because the start/stop of this setup is very difficult to toon. Linear advance is very difficult atm.. 

    CFFFP_Test frame.3mf

    Need help with worlds largest ultimaker 3d printer!!

    in UltiMaker Cura

    Posted

    LOL! I can turn on retract just not ready for it because it's going to be a challenge because of the amount of thermal mass within this setup. I will make a video and post the 3mf project file by tomorrow. I have plans to make it with not one but yes two pellet heads so that's coming! But I'd rather nail down the path of least resistance with the (2) 3mm filament heads because so much more has been done on this side of plastic flow.  No reinventing the wheel quite yet my friend.. I truly need help tuning this, there are so many more variables. But with this setup I can extrude more than a pellet system atm (800 watt potential)  I'll add a video soon.. I really appreciate your help here..!!

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