Obviously, the bridging settings, can’t seem to find a good combination of settings. Lowered speeds, volumetric speed, increased cooling.
Changing speeds and retraction options i managed to make the top cube print almost perfect, but there is still some oozing and now some stringing.
There is some shrinking effect after a few layers from the bed. Also for every print i’ve done so far, having circular holes seems to cause some dilatation on layers that are involved.
ensure that the filament is dry and calibrated → this is critical for one looking for quality in challenging prints;
Bridge settings:
Check bridge direction in the slicer preview;
Also, either ensure that at the bridge layers, the line width and layer height are large enough to ensure a proper flow or try a thick bridge option with a lower flow rate (e.g. 0.9);
Concerning vertical holes, reduce the layer height (i.e. split the hole into more layers). In FDM printers, this continues to be a limitation.
The minor imperfections are easier to deal with after solving the other issues;
BTW, the 0.16mm High-Quality default preset entails lower printing speeds, proper infill and lower layer height. In addition to an adequately conditioned and calibrated filament, I would expect improvements in all the issues.
Hi @JayZay , thanks for the ideas.
Using the 0.16mm profile indeed made the print more clean, the layers around the hole are less prominent.
But even with a thick bridge and a 0.9 flow rate on bridges, the first layers are sagging, much like before. I guess i’ll have to play around with those settings a bit more.
As for the bridge angle/direction, i don’t think in this particular case there is another viable option than the default, there are no other walls around than the 2 bridge heads to connect with.
Hi,
You’re welcome.
You can go even with lower layer heights, yet test prints usually have some goal, such as calibrating settings for a specific filament.
Concerning bridges, my suggestion is just an example.
I only used the thick bridges once for testing, avoiding them as much as possible or assuming them as sacrificial layers.
I don’t own an A1 mini, so I can only provide some essential advice. Printing long bridges can be challenging, but the concept is to optimise print flow rate, speed and cooling. The issue is that this is a multivariable optimisation problem with dependent variables and constraints.
In practical terms, when printing in mid-air, the layer height and line width cannot be controlled in the same way as when printing against a surface, so you can adjust the flow and printing speed to either print thick lines (nozzle diameter) or pull the line (making it thinner). This is what that thick line option and bridge flow allow to tune.
Also, to reduce sagging, as noticeable in your test print, you need to cool down the filament as fast as possible, which you can control as you are doing through fan speed; alternatively, you can reduce bridge printing temperature.
For me, the best way is to observe the print, which makes it easier to identify the issue and find solutions.
Regarding the bridge print direction, I found it helpful in many cases. I think the external and internal bridge lines have different settings, so it may be beneficial to optimise the printing direction of the internal lines.
All these tunes are only worth up if the filament is dry.
