I just noticed something that I don’t fully understand. I have all the nozzles for the P1P (gotta catch them all, after all) and switch them around quite a bit. So what happened today is, I switched back to the 0.4 nozzle, but forgot to switch the profile back from the 0.8mm one. However, when the print started, I got a 0.8mm line width… how is that even possible. I thought I need a 0.8mm nozzle to be able to do that. I double checked and it really was the 0.4mm nozzle. But when it started printing the infill for the first layer, the lines were very thick. Am I missing something here?
That’s really interesting. Was it PLA in your case?
I think that unless the filament you are using has no wood/fiber additions (which could increase the risk of clog) it may be possible to do that. As long as the temperature is high enough to melt all the filament at the greater extrusion rate, you should be fine.
Of course I’m not trying to encourage you to keep doing this. I’m not sure how this can affect nozzle wear and you probably might experience oozing/stringing with these settings at some point. However it’s really good to know that Bambu Lab printers can do that, just in case i somehow do the same mistake and forget to change the settings in the slicer.
Nah. Not all that surprising. Extrusion width is a function of a few different interrelated parameters. Nozzle size is one, but flow rate is another, as is how fast the printhead is moving and how far the nozzle is from the underlying layer (or build plate). You put a 0.4mm nozzle on, but the printer was still trying to push a 0.8mm nozzle’s worth of plastic. If the printer pushes out plastic faster than the printhead is moving, the plastic spreads out as the printhead moves along. It’s why the slicer has a “elephant foot” compensation feature for the first layer. You probably weren’t actually getting 0.8mm lines, though it might have been fairly close. Change the first layer height and that will change.
Actually 0.8 isn’t even the limit! There’s the term “nozzle flat size” which is the total diameter (bore + wall) of the bottom of the nozzle. Bambu nozzles appears to be 2x the bore, so a 0.4 nozzle has a nozzle flat size of 0.8 mm. Also, the cross section of the extruded line isn’t a rectangle but has a semicircle on each side (i.e. a stadium), and this adds to the maximum line width with half of the layer height at each side.
So the proper formula for maximum line width is nozzle_flat_size + layer_height, which in our case is 2 * nozzle_size + layer_height and for a standard layer height of half the nozzle size, it’s as simple as 2.5 * nozzle_size.
With a 0.4 nozzle you can thus print 1 mm wide lines at a layer height of 0.20 with good quality. Bambu Studio had an off-by-one bug that I recently fixed, so you had to say 0.99 mm. Latest beta does accept 1 mm.
I’ve used such widths in testing and it comes out really nice - but due to volumetric flow limitations you may trade speed in mm/s for speed in mm³/s (total print time should not change much though). An example of use case for this is overhang - with 1 mm line width you can do twice as steep overhangs as with the standard width! Another obvious example is vase mode (a.k.a. spiral mode).
Wow, thanks for the detailed replies. I was wondering what you could use this for. I have all the nozzles (0.2–0.8) and I am trying out different things. Trying to print with different line widths is definitely interesting. Using the 0.6 nozzle for most of my prints now, since it is a bit faster than the 0.4 one, but if I can do 0.6 with the 0.4, I might switch back.
Well you can do 0.4 with a 0.6 nozzle as well, if you tweak stuff . Arachne and Variable Height are my go-to’s for most prints. And Arachne’s default settings can be tweaked, eg. from a min. line width of 85% (of nozzle size) to 30%. I think at that point you actually beat a 0.4 nozzle using default profile for many situations (but then again you could obviously apply the same settings for a 0.4).
Out of curiosity, did you use a 0.4 mm nozzle? I’ve been reading a lot online about how wider line width will only weaken a print, but from your experience it’s sounds like that’s not the case.
I would expect a large layer height to affect strength. Using wider lines decreases the relative layer height so if anything it should be stronger. Then again there are many variables involved, such as if the wider lines increase the VFR (which it does unless we’re limited by a line speed setting) so that could make it weaker
. Arachne and Variable Height are my go-to’s for most prints. And Arachne’s default settings can be tweaked, eg. from a min. line width of 85% (of nozzle size) to 30%. I think at that point you actually beat a 0.4 nozzle using default profile for many situations (but then again you could obviously apply the same settings for a 0.4).