everything prints good except first layer  

RE: everything prints good except first layer

Hmm. I think you're referring to calibrating Live-Z. Unfortunately, the picture is so small that it's hard to make out any detail. You may want to upload it again and select options to provide a larger image size.

It's important to realize that Live-Z only impacts your 1st layer. You are setting the zero position for the nozzle above the print surface, the initial gap. After the 1st layer, every other layer is adjusted upwards from that level by your specified layer height. This means that adjusting Live-Z after the 1st layer won't affect other layers other than problems if the part becomes detached due to poor adhesion.

If you are experiencing over-extrusion after the 1st layer, consider adjusting Filament Settings->Filament->Filament->Extrusion multiplier. It starts at 1.00, and often needs to be adjusted +/- 10% (i.e. 0.90-1.10) depending on the specific filament you are printing with.

I've put together my notes on Live-Z calibration, and Prusa has a knowledge-base article on calculating the appropriate extrusion rate multiplier for your filament. You can also eyeball the extrusion rate until you get visually consistent results.

RE: everything prints good except first layer

-1.750 is a way thin, -1.500 looks best o the lot as -1.400 is a bit thick ...

Remember the first layer is normally 0.200 mm thick. And changing the Z-offset 0.100 is half the desired layer thickness.  Most of us make changes in steps of 0.025.

Settings/Tune/Flow - if you are really setting that instead of Z-offset - just means you are adjusting the wrong thing and need to get the manual out and relearn how to calibrate layer one.

RE: everything prints good except first layer

No it is not a z live adjust  height  of - 1.75.  it is 1.75 multiplyer for flow under tune .   it is not an over extrusion it is an under extrusion problem on first layer only. What I printed is not a single layer but 3 layers.  This is to show the gaps between each line on first layer.  When flow set to 1.75 the gaps between the first layer are gone. What I need to do is set flow to 1.75 for first layer then when it finishes first layer I need to set it back to .95.  I want to know is how to do this in Prusaslicer.  what Gcode needs to be entered into the program to do this.  If I have to I can change manualy edit gcode myself.  A manual on prusaslicer settings would be great but I have yet to find one.

RE: everything prints good except first layer

Why not post an image of a single layer 1 print ... but place the extrusion ratio at 0.95 (the default).

RE: everything prints good except first layer

But if you are intent in not learning how to adjust Layer 1 height properly, the reason you have to dump excess plastic to fill voids, then you can muck up the gcode using the M221 command.

M221 S{if layer_num==1}1.75{else}95{endif}

RE: everything prints good except first layer

RE: everything prints good except first layer

Hey David,

Do the tracks separate easily when you pull up that test?   The images looks like the strands are not quite welding, this is due to the nozzle being too high off the bed.  With the textured sheet many have found a need to really squish layer one to get proper welding. The idea is layer one is 0.200 mm thick. With the deep texture, the nozzle needs to be pretty close to fill properly.

Also, the built-in z-offset test is not easy to use.  You should try using a larger test that gives you time to adjust and see the result of a change.

Here's what I use ... and the link below leads to the Jeff's Life Z thread, which many find useful and informative.

Cal Circle Zip

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

https://help.prusa3d.com/article/ZhBlGFD9Ah-live-adjust-z

All said and done: you can affect layer one by changing the Print Settings>Advanced>Layer 1 Width in Plicer.  Doubling the width essentially doubles the flow. You might find that an easier solution than custom gcode.

RE: everything prints good except first layer

The first picture is from the calibration > First layer cal. test print. The test had sharp corners on turn and and an even square with no gaps. The second picture is the same test print removed and turned over. It removed in one piece and no gaps. If you look at it held to strong light is shows no gaps and even color. The last picture was taken after the calibration test prints. This is the first layer from the previous post pictures. As can be seen it has gaps. When removed it came off as a string and not a solid piece. This gcode was generated with PrusaSlicr 2.0 standard Prusa pla settings .15mm Quality MK3. This is why I messed around with Flow.

I also repeated the First layer cal. Lowering the z this only caused what I call a plowing effect. The filament is higher on the sides and the square has ribs and non uniform color when light shined behind it.

RE: everything prints good except first layer

Thanks for the G code I try this and see what it does.

RE: everything prints good except first layer

There is an incorrect setting in the slicer ... 

Upload the gcode you used to print that circle.  ZIP it and attach.   The full part if okay as long as the zip is less than 10 meg.

RE: everything prints good except first layer

No I cant pull it apart.  It comes off a one sheet.  It also sticks very good to the PC bed.  I always run the calibration test at one height.  I adjust it at the start of the run about the first 2 inches.  then let the test go.  I usually get 6 turns and the square. I look at the results and decide if it needs to go up or down I usually adjust .015 at a time for each run.  Usually I dont care about the bottom of the print but Im working on a project that requires the bottom to be the best see picture

RE: everything prints good except first layer

Here's the circle in gcode ...

CalCircle_gcode

RE: everything prints good except first layer

Ok

RE: everything prints good except first layer

Ignore that last post -- the gcode file is using Generic PLA at 195c ... it doesn't print very well. This should print at 215 ...

CalCircle_gcode

RE: everything prints good except first layer

Layer 1 on the glasses looks high.  And I have never seen delam quite like this.

Not sure what to say at this point, maybe someone else has thoughts and ideas to offer.

RE: everything prints good except first layer

Yea you just described my problem.  The part is solid except for gap on first layer. I haven't changed any setting that I know of. Ive had the i3mk3/i3mk3s for more than a year and a half. I didn't really care about the bottom.  All parts stuck like glue to build plate so it was  good for me.  Now this part I'm trying to print the bottom is supposed to be the good side and I'm looking  at it with an expert eye.   I'm going to go over the hardware side of the machine again from top to bottom. See if anything is loose. 

I'll try the new gcode you sent and see what happens.

Thanks for the help

RE: everything prints good except first layer

If you get the cal circle to be a solid welded piece by adjusting z-offset, it should get your part going.  

You might check what your PrintSettings/Advanced extrusion widths are set to. Make sure First Layer is 0.42 wide... and you could bump it up to 0.5 to add a bit more plastic to help fill gaps. But you might also put down too much plastic which can leave artifacts higher in the build.

RE: everything prints good except first layer

I was checking over my machine and I found an issues and made a few issues.  I broke the wire to heating cartridge. Bone head move.  Also Extruder gear seamed to have move a little so it was a little offset from straight line feed for the filament.  I dont know if that could have caused a problem.  I'm done now for at least a week untill my new hot end shows up.  I'm going to keep my old one as a spare.