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GregValiant

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Posts posted by GregValiant

    Ender 3 Pro - Bed Adhesion Issue with Cura

    in Improve your 3D prints

    Posted · Edited by GregValiant

    Mine needs leveling more than that.  It takes maybe a minute with my app and the touchscreen laptop.  Any leveling "print" will work so long as the X and Y numbers put the head where you want it.  When comparing the time involved in leveling, to a 3 hour print, it's a non-issue.

    Over on Reddit there are an amazing number of posts by people who SHOULD have left the BLTouch in the box (along with the SKR mini V99 they got talked into installing).  Now they have a mess.  It always makes wonder..."Hey, did you get into 3d printing to print(?) or as an electronics repair hobby?".  Because a lot of them don't have any idea what they're doing and they are often the ones giving advice to others.  Other than the Cura page (and two other contributors who are real good), there is a lot of mis-information flying around over there that is being spoken as gospel truth.

     

    Anyway, that's my "I really need another cup of coffee" early morning rant.  Sorry.

    Holes too small and outer diameter too big ? What should I do ?

    in Improve your 3D prints

    Posted · Edited by GregValiant

    Holes create a special problem.  The nozzle drags the plastic in a circle and the plastic wants to cut corners so it pulls towards the center making an ID smaller  You don't notice it as much on an OD because usually there is an inner wall to act as a dam to keep the plastic outboard.  How much it pulls to the middle is affected by a lot of things.  The phenomenon is known as the Gr5 Snot Factor after it's discoverer who had a runny nose at the time.

     

    The Shell | Hole Horizontal Expansion setting can be used to enlarge a hole.  Not all holes are round, it acts on any vertical holes in the part.  Horizontal features don't suffer from the snot factor.  In Nicko-Airbus example, the ID is .5mm too small.  A Horizontal Hole Expansion of +.25 would get the ID at least into the ballpark of being correct.  The hole horizontal expansion number works on the radius.  The downside is that the smaller holes will probably need a different HHE number to be correct.

    • Like 1

    Ender 3 Pro - Bed Adhesion Issue with Cura

    in Improve your 3D prints

    Posted

    You wash it nice.  Wipe it off with isopropyl alcohol.  Put a dusting of AquaNet Super Hold on it.  Level the bed with a piece of parchment paper or a store receipt.  Print.

    Did you watch the video?  It's kinda long but explains the process.  I look at it like this...what goes on in the little combustion chamber of a gas engine is really complicated even though it's in a tiny space.  The space under the nozzle is even tinier but it's even more complicated.  All sorts of science and techno crap, formulas, calculus, thermodynamics, probably even astronomy and voodoo.  It boils down to getting a first layer that sticks to the bed.  Some folks never figure it out.  Then they buy a BLtouch and can't figure out how to install it much less get it to work.

    Watch the video.  There are things you can do to promote adhesion.  You can kick up the Initial Layer Flow to 110%.  You can practice leveling till ya wanna puke, 

     

    Look at it...such a cute little machine.  It pushes out hot plastic and makes stuff.  What could be simpler right?

    Branchement de mon imprimante en USB avec Cura

    in Français

    Posted

    Try plugging the printer in first, and then starting Cura.  Open a model and slice it, then go to the monitor page.  Sometimes it takes a while to load.  You can also open a gcode file and then go to the Monitor page.  Cura looks for an active USB port when it starts up, but after that it doesn't look.

     

    If Cura is still not acknowledging the printer then open the Marketplace, choose Installed and scroll down to "USB Printing".  Make sure it is checked.  You might have to restart Cura if it was not checked.  Then try the above again.

     

    There are currently definite downsides to printing over the USB.  Prints can stop at any point for no apparent reason and you will need to click on the button to resume the print.  Printing via the SD card is much more reliable.  Remote printing using Octoprint/Raspberry PI is also much preffered.

    Print restart problem

    in UltiMaker Cura

    Posted

    There are a couple of little used Gcode commands that will cause that (M24, M32) but they aren't there.  I think it must be a firmware problem in that one machine.

    There are a couple of things you can try.  In your End-Gcode in the Cura machine settings for your printer add three lines at the end:

    M29 ;stops the printer from writing recovery information to the SD BIN file.

    M22 ;Releases the SD card (like an eject command on a PC).

    M21 ;Re-initialize the SD card (like when you plug it into a PC) so it can be read again by the printer.

     

    Alternatively you can try adding M0 to the end of your End-Gcode.  That will cause the printer to at least pause.  You could then restart it with a button click and then abort it really fast from the LCD, or optionally just pull the SD card out at your leisure.

    Filament change at layer

    in UltiMaker Cura

    Posted

    See, you've rediscovered Caveman Programming for gcode.  You get to graduate to Gcode Programming 101.

    Looking through what you have there you can see that after the M300 you are turning off the heaters and fan and disabling the steppers.  Disabling the steppers is a bad thing because they lose their position (you will see the XY on the screen start flashing).  If you disable steppers, you need to have a G28 to home the printer so it knows where it's at.  That is also a bad thing.  The switches on the axis are crap and aren't very repeatable for positions.  They are good enough when used once per print, but if you home a second time during a print you can get a layer shift of .5mm because of the switch inaccuracies.  You are also printing the purge line for the second print.  Not good.  Since your print is only 7.2mm tall it works, but what if it was 30mm tall?  Crash.  And the second print can't have a brim or skirt either.

    So look through the code and see what you can throw out.  You can start with the M140 S0 line and M107 line that are right after the M300.  Throw out the lines that turn off the heaters and disable the steppers.  Throw out the purge lines.  What you end up with is mean and lean, straight and to the point.  Yes, you absolutely need the G92 E404.xxx line to sync the extruder back into what will follow.  You will also need to remember to move in the Z to get above a print before you try to move in the XY.  That will avoid crashes.

    Regarding the blob - What you really need is another part on the build plate.  A part that always prints first so your hot end has a place to leave a blob before it goes to work on the real parts.  Maybe a part floating off the build plate higher than your real parts so it needs support, and Cura will always print support first.  The blob ends up on the support.  Kind of a purge tower.

     

    3d file sliced in cura not printing; 3d print head grinding off of belt.

    in UltiMaker Cura

    Posted

    The printers aren't sophisticated enough to tell you there is a problem with the card.  They just start doing weird things and then you have to scratch your head and wonder what the heck is going on.

    Congrats.

    Are you planning on gluing that mess together?  What I do is put matching 2.2m holes into each part about 3mm deep.  When I assemble the parts there are matching locating holes.  I cut pieces of filament and glue them into the holes in one part, then the mating part knows where to locate.  It gives a little more strength as well.

    Cutting Objects in Cura

    in UltiMaker Cura

    Posted

    "I used to be a chef, chefs do normally not need any programming skills....".

    I beg to differ.  You had to flip over the little glass thingy with the sand in it to program it for 3 minutes.  I would consider that analog programming.  The oven controller had to be programmed for temperature and start time/end time.  That's digital programming.  I think you're selling yourself short.

     

    The support blockers can be used as mesh modifiers.  Drag one over, resize it, set it to "Cutting Mesh" and enter the appropriate settings to keep anything in the overlap from printing.  Typically setting the Wall Thickness, Top Layers, Bottom Layers, and Infill Density to zero for the overlap will do the trick.

    Exeed build volume error (Ultimaker S5)

    in UltiMaker Cura

    Posted

    In your screen shot of the printer, you can see that the red/blue/yellow origin icon of the printer is in the center of the build area.  When the benchy is sliced where it is sitting in the image, the gcode will contain negative X values.  But the printer origin is really in the left front corner.  When the gcode comes into the printer with the negative values, it can't get to them because they are off the build plate and so there is an error.

     

    In Cura, click on your printer, then Manage Printers / Machine Settings and in the dialog de-select "Origin at Center".

     

    So some basic questions:

    1. Is printer origin the same as model xyz = 0,0,0?  No.  The printer origin should be left front corner.  The model origin is the "center of geometry" of the model.

    3. In other words, how is printer xyz origin related to model xyz coordinates?  They aren't.  Cura will bring in a model with the local 0,0,0 at center of geometry and place it on the build plate at the mid point of the build plate (if it can).  The mid point is determined by the size of the build plate you have entered in Cura (in Machine Settings).  You can use the grips to move the model anywhere you want.  Now, for some things (like model placement) Cura will consider the mid point as 0,0,0 but that is a local relative origin.  The real origin, and what determines the gcode numbers, remains at the left front corner.

    To make it more confusing, when "Automatically drop models on the build surface" is selected then Cura uses the XY of the model center of geometry, and the intersection of those planes with the lowest "Z" of the model.  Usually, the lowest point is a plane, but it doesn't have to be.

    Layers split with litte force, due to missing "full layer"

    in UltiMaker Cura

    Posted

    I think what is happening is that Cura is calculating based on 2 wall loops, and there is no "Top" or "Bottom" in that area.  If I change it to a single wall, then the top and bottom show up and the upper portion is supported with a regular interface.

     

    So yes on using the support blocker to modify that joint with 100% infill (or more walls).

     

    Would it be possible to add a chamfer at that joint?  Even a small chamfer is better than none and would cause more plastic to be put in the joint.  You would still need the support blocker though.

     

    Bevels in Tinkercad are not printing

    in UltiMaker Cura

    Posted

    The beveled edge may be getting lost due to the layer height setting.  At a .25 layer height it would only be 2 layers tall.

    As gr5 says, post a 3mf file.  At the least post the model file (STL or OBJ).  As a retired Fire Fighter/ Fire Investigator / draftsman / forensic engineer / ski patroller / lifeguard / CNC programmer / Mechanical Engineer / Pirate, I have some interest.

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