Line Width Differences in Calibration Print
I printed the 40 x 40 x 40 precision method calibration cube in vase mode as described in the Extrusion multiplier calibration guide. I used the stock 0.4mm nozzle and set the Extrusion Width setting to 0.45mm in Prusa Slicer 2.4.2. Every item in the Extrusion Width setting was set to 0.45 mm. The average printed line width for each side of the cube is:
- Front, Printed Left to Right = 0.43
- Right Side, Front to Back = 0.43
- Back Side, Right to Left = 0.47
- Left Side, Back to Front = 0.47
Can anyone help me understand why the line widths are under-extruded when the print head moves right and back and over-extruded when the print head moves left and forward? Thank you.
RE: Line Width Differences in Calibration Print
Heck, those numbers are way closer together than the ones I get by measuring the cube with a really accurate micrometer. So long as my actual prints turn out fine - and they do - I use that test only for tweaking the extrusion multiplier and don't read anything else into the results.
RE: Line Width Differences in Calibration Print
I just thought it was strange that the line widths depend on the direction in which they’re printed. The only thing I can think of is the bed and print head are both moving a bit slow one direction and a bit fast the other.
RE: Line Width Differences in Calibration Print
Or maybe a (unilaterally) worn nozzle?
RE: Line Width Differences in Calibration Print
That looks like only 40 microns difference in the strokes. Is that really significant in terms of print dimensions and quality?
RE: Line Width Differences in Calibration Print
The differences cancel each other, so print dimensions and quality are great. But I’m a fiddler, and I couldn’t find any explanation for these results. C’mon, don’t you think it’s curious the differences are clearly correlated to print direction?
RE: Line Width Differences in Calibration Print
More of a question than and answer... Would it be possible that has any thing to do with how level the bed is? I know it auto-levels it, but on my mini it can still be off a little. The closer the nozzle gets to the bed the wider the bead generally.
RE: Line Width Differences in Calibration Print
@prusa-fanatic
There is hope for you sir. you have a good Eye.
The closer the nozzle gets to the bed the wider the bead generally.
By the numbers this is not supposed to be true. In reality it is true, I have had to prove this to several, educated numbers loving people here. Sometimes it takes them a bit to understand, because they are number lovers. you have to look at whats really happening. Note: this is an art form.
I'm going to make a prediction right now, that you never have a problem with what has become known as "bulge", and yes I'm laughing as I type this. But, if you do I bet you will see what the real culprit is.
With Respect,
Swiss_Cheese
The Filament Whisperer
RE: Line Width Differences in Calibration Print
That’s the spirit. I wondered about this too, and don’t think it’s a bed level issue. First, if the bed is tilted so the right side is lower, that might explain the thinner right and thicker left, but it doesn’t explain the front-back difference. And I think the numbers would be more scattered with a tilt toward a corner.
Second, I think a leveling issue would be worked out in the first few layers. Assuming the same volume of filament is extruded, the narrower lines (measured on the X & Y plane) are going to be thicker (measured on the Z plane), and the wider lines would be thinner. So I think the varying thickness of the lines would correct a bed level issue.
But, the cube is printed in vase mode, so after the base is printed, each layer starts and ends on a different Z plane.
RE: Line Width Differences in Calibration Print
True but then again when you are talk such a small difference it could be virtually anything.