Printer: H2D
Nozzle: 0.4 mm
Material: PETG-CF (Titan Grey)
According to the Gcode, the speed/accel stays consistent throughout. No other inputs like flow change, etc.
But…
The result isn’t consistent.
The transition (where the new line hits the hole), creates a glossy patch. As though the speed drops, flow increases, or line spacing narrows.
It’s because Bambu Studio doesn’t have a monotonic ironing mode. Which is extremely annoying.
I’m curious how monotonic solves this, as the line path wouldn’t change in my model.
But yea, unless your model doesn’t have features like holes, ironing is basically useless.
the shine changes because it’s not printed at the right time. Or, the lines are not printed “chronically continuously”
This is why it’s happening. The stupid pattern prefers one side to be completed first,
then go for the other side and finish the other patch. This creates the nonuniform look. It’s not because that the nozzle is jumping over the hole. Rather, it’s because that the nozzle is NOT jumping over the hole to print monotonically.
But this highlighted area is printed continuously. There’s no line jumps.
If monotonic, how would that transition at the hole happen? Or is the transition not the problem? Maybe I’m not understanding it (but anyway sounds like there’s no workarounds?)
if a line is printed significantly faster than other lines nearby, then it looks weird.
if it’s a gradual change, then the variance would look much smoother.
when it’s at the hole area, the nozzle ideally should be printing from the edge to the hole, then travel over to the other side of the hole, then print to the other side of the edge. So this entire “two segment ironing line” can have a similar printing time to previous lines. And the shines should look similar. Which is why “true monotonic ironing” is better. The nozzle should just scan through the entire surface from one direction and make the travels when necessary.
Unfortunately this feature doesn’t exist in current slicers. They all try their best to prevent travels, creating discontinuous look whenever there’s a hole or feature on top.
But the Gcode shows the speed/accel is doesn’t change, unless there’s some hidden changes?
If it’s a matter of line length.
The lines at the corners are shorter, but manage to have the matte surface.
see my updated reply above.
that’s because it’s printed “chronically continuously” with previous lines.
Whenever there’s a huge jump of:
- timespan it takes to print a line
- time point of when the line is printed
…compared to the previous line, you get a huge shine change.
For your matte corner:
it looks natural because:
the time span it takes to print a line changes gradually as it’s getting closer and closer to the corner.
the time point of when the line is printed, is always right after the previous neighbouring line.
which is why it looks good.
For your uneven patches:
Which is why i hate ironing in general, it’s a broken feature currently that does not really function as expected.
At any given point on a line, isn’t the time span equal?
I know you’re implying each line length takes slightly longer to print, creating a gradual gloss gradient (and maybe that’s more related to cooling time than print speed)
But in the patch area, take any 5 mm length of each line. It’ll print in let’s say 0.1 second. The next 5 mm’s (of the same line) are also printed in 0.1 seconds. The previous 5 mm’s don’t affect the following 5 mm’s, as every segment is printed in 0.1 seconds.
If the lines followed these 3 paths towards the hole (red, orange, yellow), I wonder if the patch would gradually turn matte.
Tomorrow I might try a height modifier, and adjust regular monotonic layer to print with ironing settings. (Ex, if normal line width = 0.4 I’ll adjust to match ironing line width)
the shine changes because the filament was cooled down but then remelted by the new neighbouring line, and then cooled down again. repeated melting and cooling changes the shine. and this is dependent on the period between “first laying down the line” and “getting remelted again”.
anyway, my point is, ironing is a broken feature that doesn’t work whenever there’s a hole or something.
But the neighbouring lines in the patch area are printed consecutively, without a melting/cooling cycle. Somehow they’re still glossy.
I’m just trying to understand why it’s happening, so we can figure out some workaround. Just not convinced it’s repeated melting/cooling, or time per line changes.
