Printing weirdness continues…

New Home Forum Milled Printed 3D Printer -MP3DP Troubleshooting – MP3DP Printing weirdness continues…

This topic contains 86 replies, has 7 voices, and was last updated by  Jeff 6 months, 2 weeks ago.

Viewing 30 posts - 31 through 60 (of 87 total)
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  • #90241

    Jeffeb3
    Participant

    Also, any way in Slic3r to adjust where the print goes on the bed? It always autocenters and I can’t figure out how to stop that…

    Left mouse drag, I think.

    #90310

    Jeff
    Participant

    I do that, but as soon as I let go of the mouse button it just snaps back to the center  of the print bed.  I’m at gotta be a setting I’m missing.  I am launching slic3r through repetier so maybe that’s causing it?  I position the part in repetier where I want it, but then slic3r does it’s own thing.  If I use Cura through repetier, it works fine…  strange. I need to dig in deeper to slic3r to see what is going on.

    #90319

    Jeffeb3
    Participant

    Ah, there is a checkmark in the Configuration -> Preferences -> Auto center.

    #90322

    Jeff
    Participant

    Thanks Jeffe!  I’ll check for that this afternoon.

    #90345

    Jeff
    Participant

    This is strange.  I had that option unchecked so it shouldn’t be autocentering, so I just checked it, closed out of slic3r and then unchecked it again, and not it is working as it should…  lol.

    #90352

    Jeff
    Participant

    Ok. Here are my latest prints. Just the first layer, using the default settings that Ryan listed on the extruder assembly page for my Slic3r settings. It looks to me like my print head is too close to the bed?  It also appears that it is “pushing” a glob of filament in front of the head.

    These are 2 different pics from 2 different tests.

    #90359

    Jeff
    Participant

    So, here are some videos of my latest testing.  Leveled the bed as good as I could but I seem to have a slight variance in the Y Axis on the Left side of the printer (the one with only 1 leveling screw) that I can’t get out.  It’s only about 0.08mm but it is there.

    Anyway, the PEI sheet seems to be helping but things still aren’t sticking correctly.  I heated the bed up to 65c and let it sit for 10 mins before I started printing just to give it enough time.  As per my post above, my slic3r settings are the ones from Ryan.  It looks to me like I’m either too close to the bed (which doesn’t make sense) or not extruding enough filament.  The filament is “curling” up behind the print head and forming an arc before it touches down on the PEI sheet.  It’s like it is hitting the sheet right out of the head with enough “force” to then make it come back up off the sheet before it flops back down again.  Hopefully the linked videos can help you guys help me because I am loosing my mind!  lol.

     

    #90366

    Aaryn
    Participant

    the videos are great help.

    The nozzle is too far away form the bed.  The first layer the nozzle should be close enough to the bed to cause that round bead of extruded filament to have a flat top surface.  Not so close to the bed that it causes the sides of the bead to deform into a rough jagged pattern.  Difficult to explain. but I hope that makes sense.

    #90388

    Jeff
    Participant

    Thanks Aaryn, that does make sense.  I was thinking I was too close but your explanation makes sense.  I’ll modify my gc0de to drop it closer to the bed and see what happens.

    #90389

    Jeffeb3
    Participant

    I agree with Aaryn. I think you need to get between 0.1-0.2mm closer.

    I personally would use the Z endstop screw to bring it down. If you turn it in a bit more, the Z will go lower before it hits it.

    #90460

    Ryan
    Keymaster

    The first video shows a clogged nozzle and the nut is on the wrong side. I have assembly instructions with lots of pictures. That nut needs to be on the other side or you will get thermal issues. This is an all metal throat, the balance with PLA is tricky and that seems to solve it. As for the nozzle look up “cold pull”, basically you start with a cold printer, heat up the hot end and when it gets to about 100C pull the filament out and it usually brings the crud with it.

    #90475

    Jeff
    Participant

    Thanks Ryan, I fixed that issue and now am dialing the entire thing in.  I’m very close but am having an issue where the “left” side of whatever I print looks terrible but the other 3 sides are fine.  I’ve included a pic and links to some video’s showing the weirdness.

    Attachments:
    #90480

    BT
    Participant

    Check the y-axis bearings/rods.  There’s probably something going on where it moves smoothly in one direction but not in the other (maybe the bed gets cocked or a rod is loose).

    #90483

    Jeff
    Participant

    Check the y-axis bearings/rods. There’s probably something going on where it moves smoothly in one direction but not in the other (maybe the bed gets cocked or a rod is loose).

    Thanks BT.  I was thinking something along the lines of something with my bed or bearings but couldn’t figure out why it was only the one side (and the same side every time).  It makes sense when you just explained it.  The issues are only showing up when the bed is moving in the Y Negative direction so it makes sense that something could be causing it to stutter in that direction.

    Edit:  I think you called it.  I just did some testing with more rapid movements to see if it would exacerbate the problem and moving in the Y Negative direction the bed is shuddering.  The interesting thing is – this shudder doesn’t happen if I’m not printing.  It only seems to happen during printing functions. Even if I do rapid movements by just sending G-code (G1 Y0 F8000) it doesn’t shudder at all and is very smooth.

    #90489

    BT
    Participant

    Hmmm.  I’m thinking there’s some cross talk going on.  Does the shuddering occur when the heated bed is on?  If so, see if you can separate the cables.

    #90491

    Jeff
    Participant

    Hmmm. I’m thinking there’s some cross talk going on. Does the shuddering occur when the heated bed is on? If so, see if you can separate the cables.

    Good question.  I’ll have to look into that as well.  The strange thing is it’s only in the Y Neg direction.  The heated bed and the Y Stepper are in different wire sleeves but I guess anything is possible.

    #90609

    Jeff
    Participant

    Well, I got sick of redefining insanity by trying to get the thing to print properly over and over and over so I went away and routed out 2 new Front and Back plates and didn’t paint them this time.  I was beginning to wonder if I had too much paint in the grooves where the YClips go and it was causing my Y Rods to be slightly “racked” which may be causing too much tension on the bearings.  Installing those now and we will see what happens.

    I have to get this thing working properly soon – my daughter is begging me for a Purple Giraffe.  Lol.

    #90640

    Jeff
    Participant

    Got the Front and Back flat parts replaced.  First test print and it’s doing some weird crap still with the Y axis – at least I think it’s the Y Axis causing the issues.  When it does an X Axis movement it’s all good.  When it does Y Axis it seems fine as well.  It seems to be “bumping” along when it is doing an XY movement at the same time (when it’s doing the infill of the cube I am printing).  Here is another video to show what it is doing.  Maybe I have some bad bed leveling issues?  Something in the Gcode (seems unlikely as I am still using Ryan’s defaults for Slic3r)…

    #90642

    Jeff
    Participant

    Stranger and stranger – even with all that strangeness, the print I just finished is the best one I’ve made to date…

    #90645

    Jeffeb3
    Participant

    The infill is also faster. I wonder if that’s having an effect.

    I can’t really see the bumping in the video.

    You could send some long movement commands and see if you can tell what’s having trouble. something like:

    (X)
    G1 X10 Y10 F2000
    G1 X180
    G1 X10

    (Y)
    G1 X10 Y10 F2000
    G1 Y180
    G1 Y10

    (XY)
    G1 X10 Y10 F2000
    G1 X180 Y180
    G1 X10 Y10

    I find I am more sensitive with my fingers than my eyes, so I will rest my hand on the printer while it’s moving and see if I can feel it grinding or lurching or something. Just keep your hand away from pinch points. Feel for the bumping while it’s printing so you know what it is, then try again without printing.

    If it’s having motion problems when not printing, then that’s got to be fixed first.

    If its only when printing, then its either about the speeds, or the nozzle is hitting the print. If it’s hitting the print, then it could be a temp. or over extrusion problem.

    #90693

    Jeff
    Participant

    Definitely only when printing.  I think I’m over extruding as it looks like the print head is hitting the already laid down filament as it moves.  I’m gonna play with adjusting my extrusion multiplier and see what happens.

    #90697

    BT
    Participant

    Did you verify that when  you request a specific amount of filament you get it?  Mark your filament 60mm from the top of the extruder. Extrude 50mm and then measure from the top of the extruder to the mark – it should be 10mm if it’s not, then your extruder steps/mm should be adjusted.  Similar to what you did earlier when you verified the X, Y, and Z motion.  You can also check the diameter of your filament in a couple of places to see how close to nominal it is.

    #90699

    Jeff
    Participant

    I did verify that it is extruding properly (or at least as close as I could measure with my calipers).  I did a 100mm extrusion test and it seemed to be accurate but I will run that test again.

    I measured my filament to 1.72mm and have entered that into Slic3r.

    In the last test print it did, it’s definitely an over-extrusion problem – or something related to that.  The only time my print bed shudders is when the print head is doing infill and going over what it already did (I’m using a rectilinear infill pattern).  I’ve also noticed that at points in the print I’m getting little blobs of filament.  I think I need to start looking into my extrusion multiplier (which is set to 1 right now).

    Should I be using adaptive slicing?  I’m not at the moment.

    I’m also starting out my print jobs with the Z Zero just kissing the print bed.  I find that if I lift it up even about 0.05mm then my first layers aren’t sticking.  I do need to spend more time leveling the bed I think.  I think I’m also going to be a glutton for punishment and route out the Y Plate out of 1/4″ MDF.  Right now I’m using the Y Speed Plate and since it only has 3 attachment points, getting true bed level seems to be something I can’t achieve (although I really haven’t spent much time with the level since I put in the new Front and Back plates with no paint on them to see if that help).

    #90701

    Jeffeb3
    Participant

    I measured my filament to 1.72mm and have entered that into Slic3r.

    This will cause it to extrude more.

    Should I be using adaptive slicing? I’m not at the moment.

    Nope. That’s more for fine tuning and faster printing.

    Remember that the software makes it seem more exact than it is. The extrusion multiplier and filament diameter are tuning knobs to get you what you want. Don’t be afraid to adjust them to something that’s not “right” if it gives you good results. So I would put the filament diameter back at 1.75mm. If that doesn’t fix it, then reduce your extrusion multiplier by 5%. If that works, you can start to tune that closer.

    You can also get away with a little under extrusion, but over extrusion, nope. Are you using about a 20% infill? That should help be tolerant to some extrusion problems too. If we can get a good easy print, then we cam make it harder.

    #90708

    Jeff
    Participant

    Thanks Jeffe – I will do what you suggested and let you know how it goes.  I’m using 40% infull but will drop that down as well.

    #90709

    Jeffeb3
    Participant

    I’m using 40% infull but will drop that down as well.

    40% should be fine too. Weird.

    #90713

    Jeff
    Participant

    Well, I set my filament back to 1.75mm and extrusion modifier back to 1 and the infill to 20.  I was still having some bumping during the print so about 1/2 way through the print I paused it and raised my Z 0.03mm and that seems to have solved the problem – at least during that print.  Definitely getting closer but still not there yet…

    #90720

    BT
    Participant

    While your printing, if you think it’s overextrusion, there’s always the option of adjusting the flow rate.  You could tweak it until things come out the way  they should.

    #90728

    Jeff
    Participant

    Good call BT.  I adjusted the Z height but didn’t think of dropping the extrusion by about 5%.

    #90762

    Bill
    Participant

    You can also look at your retraction settings. When the head slows or stops to do a direction change the pressure in the nozzle allows an extra bit of bead to ooze out. Retraction backs the extruder off just a bit in those cases, minimizing the ooze.

Viewing 30 posts - 31 through 60 (of 87 total)

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