Infill not overlapping perimeters
Hello,
I have an I3MK3S latest firmware and latest Slic3r. It is an ASSEMBLED by Prusa Model, so I assume does not have any calibration issue.
I performed only the Z-Calibration.
I have just done very few test print and all was perfect. I was even able to print a bolt & nuts that screws perfectly 😀
Then, today I sliced a new object, and important I changed the filament with a Black PLA (generic).
From the sliced preview inside SLic3r the fill is basically attached to the outside perimeter of the holes circle.
The profile is the Original Prusa I3 MK3S - 0.20mm SPEED MK3.
I exported the gcode and I started the print. Due to the fact that the object it enough big, I have all the time to see the first layer during the print.
I noticed that holes perimeters were not reached by the infill. The infill was too much far, and probably the print will be a failure.
UPDATE: IT WAS A FAILURE
The object warped and detached from the bed.
However now I got a close picture of the bottom layer:
The Slic3r Prusa profile is set to 25% overlapping, but looking at the picture, is more than 100% far from the touching 🙁
Looking at it I could say that it should be too far from the bed, and this cause also bad adhesion and detachment.
So, I though to the following possible causes:
- Filament Diameter: currently 1.75 in slic3r,, measured in some filament part is around 1.73, 1.72, 1.75
May be I should decrease to 1.70 so that it mold more plastic and the perimeter and the zigzag fill will overlap
- First layer too high: the Live Adjust Z may be too high. Lowering it may squash enough the filament to reach the borders, and attach better.
I already decreased the Z value to something 0.540 it seemed good, but it was not. Probably I should decrease it or recalibrate Z-Axe.
- Firmware bug ?
I don't think so.
- Any other idea ?
Regards
Re: Infill not overlapping perimeters
Definitely live-z too high, the first layer lines should be joined and the second layer should not be visible like it is in your picture.
If all you have done to set the first layer live-z is use the inbuilt PRUSA first layer calibration from the LCD menu, then this is not enough. It is useful to get 'in the ball park' so to speak, but then you really need to print a 1 layer square at 0.2mm height using the 0.4mm nozzle of at least 75mm and make sure this is correct, also I have found this is best to do with a light coloured PLA.
What you should end up with is a solid flexible square (That doesn't sound right, solid and flexible!). A square without gaps between the lines and it should be fairly tough and not pull apart easily.
If your too low, you will end up with a rough surface looking like it has a pill, fuzzball, bubble or lint etc, this is due to the nozzle pushing plastic out of the way.
Ideally, you want as smooth a finish as you can get which is also the strongest you can get without any fuzzballs. Do test prints, peel off, hold up to the light and make sure there are no gaps, try to pull apart, if you get lots of separating line, drop it down a bit more and test print again.
I find the onset of a matt finish is about right. Get this first bit correct and you will end up with good strong prints without gaps in the first layer.
Now the reason I said to use PLA is that PETG for instance, likes to have a slight offset applied to it for printing which is not ideal for setting the first layer live-z. in my case I find an offset of 0.025 seems to work well for me.
Tip: Whilst doing the test print, use a bright LED torch to shine at the print (Best to use a light PLA for this), and if the layer lines are not joined, you will see the bed between the lines, you need to look at 45 degrees along the layer lines direction and close to the printer and will see the layer lines joining up. move the live Z no more than in 0.025 increments when you are close and if you get the light right you will see if the PLA is shiny or matt finish along the top surface.
Note, the bed may not be perfectly flat so don't worry too much if there is some variation across the print, as long as it is all joined together, a small amount of fuzzballs towards one edge of the print, may be unavoidable, but making it all perfect is another ballgame, lets get you printing reasonably good first.
Once you've got this first square printing well, you can go up to more squares say a 3 x 3 grid around the bed, then do the same, but now your middle square should remain good, and you can do some slight adjustments for the different edges from the LCD item bed levelling offset to get an even print across the whole bed.
Again, each first print should not have visible gaps when held up to the light.
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.