Jump to content

GregValiant

Expert
  • Posts

    5,191
  • Joined

  • Last visited

  • Days Won

    212

Posts posted by GregValiant

  1. Nice video.  ("You do not have permission to access this document" when I tried the zip file link).

    In the video, once the raft is done printing your printer goes through the moves for the bottom of the box and for the draft shield, but does not extrude any plastic.  From the CFFFP gcode file you provided here is the transition between the top layer of the raft, and the first layer of the part:

    G1 X107.77 Y102.9 E892.07564  ;The last extrusion of layer:-3 is at Z=0.9 and is the top surface of the raft.
    G0 F600 X107.77 Y102.9 Z1.4     ;The Z moves to 1.4
    G0 F4200 X77.563 Y85.94
    ;TIME_ELAPSED:379.038926
    ;LAYER:0
    ;TYPE:WALL-INNER
    ;MESH:Spiral_Cube.stl
    G1 F3000 X77.713 Y85.94 E892.07748  ;Extrusion starts on the bottom of the cube at Z=1.4.  The air gap is .5 to make it easier to remove the part from the raft (at the cost of a poor finish on the bottom of the part).
    G1 X102.44 Y85.938 E892.37972

     

    So the printer should be pushing plastic but it doesn't appear to be.  The X and Y move to the proper points as described in the gcode, but the E is odd.  Or maybe it isn't.  In the settings section at the end of the gcode file it says you have Initial Layer Flow and Print Flow set to 70%.  Is there a reason for that?  The flow for a raft is very heavy, but a 70% flow into a .5 air gap may not be enough to get the plastic to stick to the raft.  It may be extruding but at such a slow rate that it looks like nothing is happening until finally it starts air printing.

  2. Yes, PauseAtHeight doesn't work well if you select "at height" but should work as expected when "by Layer" is selected.  The "gcode flavor" determines what Cura uses as the actual pause command.  For my Ender with Marlin firmware "M0" works.  For other printers it might be M25 or M226, or M1.  It all depends on the firmware.

     

    If you are using Z-hops in Cura then "by height" doesn't work because the Z keeps moving up and down in the gcode file.  If you are using Adaptive Layers then Cura is adjusting the layer height to the model and the chances of you entering a Z value that is actually present in the file isn't good.

    • Like 1
  3. Right after homing (from the LCD or via a G28) and before the print head moves anywhere else, the display will show your Home Offsets.  Mine is X-1.00 Y-4.00 Z 0.00.  Your X and Y values will likely be different but your Z should be 0.  If some command has changed your Home Offset Z to a negative number then the print isn't starting on the bed, but in the air.  Within the Gcode file ";layer:0" is at Z1.4.  That sounds reasonable.

     

    You can slide the model on the build plate in Cura to print it in a different area of the build plate of the printer.

  4. All the layers are in the gcode and the gcode finishes up correctly.  We'll see what Torgier comes up with looking at the 3mf.

    I'm going to assume you are printing via the SD card.  The problem you are seeing can happen when an SD card gets corrupted.  You copy a gcode file to the card but some of it lands in a corrupt sector.  Re-formatting a card usually sorts this out.  If you are printing via USB there are other things that can happen to stop a print. 

    • Like 1
  5. When I open your gcode file in Cura it looks OK.  Going through the file it looks OK there too.  I don't see any reason why it would not print.

    There are purge lines that should be on the left side of your bed.  Are they printing?  Is the skirt printing?

  6. It says it will take 2.5 hours to print.  That is more than 1 layer.  It might just be a preview problem.  When you generate a gcode - how big is the file?  If you open the gcode file in Notepad and search for "Layer" it should start at layer:0 and continue to the top layer.

  7. I just timed myself.  4 minutes 45 seconds to clean, dry, and hairspray the glass, and to level the bed with my piece of parchment paper.  I no longer run from place to place.  I am old and infirm.

    I would guess that to write a plugin taking all the things in my previous post into account, and debugging it sufficiently would take at least a month of intense concentration.  I do not do "open source" work.  Someone would have to pay the freight.

    Or I can spend less than 5 minutes cleaning and leveling, and then go fishing with a high level of confidence that the print is going to be fine because with a clean and level plate - they always are.

     

    Or I could just buy a second build plate to use while #1 is in the dishwasher.

  8. Unless you know that some other production printer shares your printer size, firmware flavor, etc, you have to add it as a "Custom FFF" printer.  After adding it and selecting a name, go to Machine Settings and make changes to the bed size, shape, and the other things there.  Very few non-delta printers use Center Zero so make sure that is turned off and you need to select the proper "Gcode Flavor".  If you are unsure of the "flavor" start with Marlin, but you really need to check with the printer manufacturer and find out for sure what firmware the printer runs on.

    The "Print Head Settings" (X Min, Y Min, Gantry height, etc.) don't become involved unless you were to select "One at a time" as a print mode in Cura.  

  9. I'm going to put my money on a clog at the hot end of the bowden tube.

    As the X carriage goes back and forth, the bowden tube rotates in the lock fitting on top of the heat exchanger.  There are small blades in that fitting to keep the tube from being pushed out, but they cut into the tube and eventually it does back out a little bit.  That creates a gap between the nozzle and the end of the bowden tube.  Retractions pull molten plastic into the gap and after a while it impedes the filament flow.  It continues to work it's way upward into the cool zone and creates a partial obstruction. You get what you got...nice part, everything is moving right along, and then bingo - under-extrusion.

    The only real fix for the stock Creality hot end is an all metal hot end.  They can still have this problem (same type of lock fitting) but it happens over a much longer time period and you can get through a 24 -30 hour print. 

    Before I start any long print I pull the tube out of the hot end and cut 3mm off (a nice square cut) and I start with a freshly cleaned nozzle.  I found a coat hanger that was the exact diameter of the throat of the hot end and with the nozzle out, and the hot end warm, I shove it through from the top.  It almost always pushes a plug of plastic out.  Heat creep is a similar problem, but I had altered my hot end cover and installed a nice 4015 fan.  Those pneumatic "push-to-lock" fittings that are used to secure the bowden tube were never designed to hold something IN.  They were designed to keep something from being pushed OUT.  That isn't the same thing.  1) All metal hot end.  2) Preventative maintenance on the hot end every 20 hours of printing and before any long print.  3) Clean the blades of the hot end fan every once in a while as they can pick up loose strings of filament and cooling efficiency will suffer.

    • Like 1
  10. You need to level your bed.  Along with insuring that the first layer is uniform thickness across the whole surface, it insures that no point of the bed is above zero.

    Cura never generates a Z value less than the Initial Layer Height and that is always a positive number.  Cura has no idea where your build surface is.  It's up to you (or your Auto-Level system) to make sure it is at or just below zero.  There are a lot of videos that cover leveling for printers like yours.

    • Like 1
  11. "Am I the only one who would love to see such a setting?"

    I haven't personally heard from everywhere, but in this arm of the galaxy...yes.

     

    A workaround would be to write yourself a plugin that would pull all of the ";TYPE:WALL-OUTER" and "TYPE:WALL-INNER" code that is in layer 0 and move it to the beginning (just after the skirt code but you don't seem to be using one).  You could copy and paste and do that by hand as well.  The E would need to be adjusted with G92 at the beginning and at each transition you create so the extruder stays in sync with the pasted code that follows.  That would be true of a plugin as well.  You may need to add Z-hops to keep the stringing down.  Trying to split that further down to "1 or 2 walls" would get complicated.

     

    Follow @Mari's advice and get a first layer that stays down.  @gr5 has made a good video on leveling and adhesion that he might share.  My advice is to unclutter the build plate.  Trying to print that many details at once is always problematic.

    • Like 1
  12. The bottom of the model isn't flat on the build plate. 

    You can adjust the model or in Cura, select the rotation tool and "lay flat".

    Or select the Move tool and set the "Z" to -0.2.

     

    There wasn't enough room in the gap at the right end for Cura to put support.  That end would have air-printed.  The size would have actually been OK.  It was just the skirt that made it look like it wasn't sized correctly.

  13. I wrote a little app for calibrating Accel and Jerk.  After some trial and error the max speed I allow is 400mm/sec.  At 400mm/sec, 3000 Accel and 30 Jerk the Ender3Pro will average 340mm/sec in a round trip from 0,0 to 230,230 and back.  At speeds above 400, the stops and starts are so abrupt that the belts skip and the machine can definitely hurt itself.  It's ugly.  A larger build surface would allow higher top speeds but in my particular case, the hardware can't take it.  The heavier Y axis is especially problematic.  Prints might self-release.

    I will not be taking the printer out to Bonneville any time soon.

     

    Here.  It is an unsigned Windows (only) app in VB.net and uses Marlin commands.  There are a few different race courses.  The circles use G2 and G3 commands.  Sending commands for the Nürburgring course was a problem.

     

    That's out of the way. 

    So @gr5, did you know (or did you have to look it up) that the indicated speed was the speed of light? (actually 1/100 the speed of light (and I did have to look it up) but that's close enough for me).

     

  14. I use other peoples questions and problems as tools.  I do some research, play with the software, and see if there is a way around, through, over or under a problem.  It helps me to develop my own skills as a designer and printer of plastic craptastic.  It also gives me something to do while waiting for a color change or other pause event.

     

    So I had played with your situation for a while and really couldn't come up with anything except "slice twice & splice".  Several hours later I decided to try again, and there it was.  A big blocker on top resting on the little blocker in the hole.  I think it was the height of the hole blocker being set to 3.84 that made the difference.  Then the big blocker bottom is at 3.84 so it takes over from there and doesn't block the walls.  Or something like that.  Anyway, it worked.

    The 3mf file has the settings for the blockers as well as the rest of the Cura settings.

    Have a good holiday.

×
×
  • Create New...