I am by no means an expert but I am hoping to start a discussion and collation of advice on printing tall (and narrow) objects. It seems to be a frequent problem Bambu Lab owners have and there is not much collated advice I have seen.
The Bambu Lab line of printers are fast. Tall and Narrow prints are prone to significant torque, acting as a lever arm according to the formula:
Torque = Force x Distance
Thus the combination of the speed and the nature of the print means it is easy to break supports or dislodge the print. Here are some of the principles I have learned but do please share your thoughts on this. Ideally, this could become a new Wiki article.
- Strong Bed Adhesion
a) Plate type +/- use of glue
b) Use of brims where first layer contact is small
c) Increasing Bed Temperature - more adhesion but makes print more prone to elephant footing. I go with 60-65 sometimes. - Stable printer
a) A fast printer vibrates which may cause layer shifts, poor adhesion, poor quality overhangs
b) Placing the printer in a stable location will ensure quality and success - Supports
a) Organic Tree support base is wide in proportion to length = higher chance of success as the base spreads out the force over a larger surface area.
b) Normal supports are good for a large planar area especially when being supported directly from the bed. Normal supports together strong; weak in patches.
c) Support brims: These help but may still detach or tear as they do not spread out force much.
d) Support infill (interface pattern): Consider using this as the support gets taller to prevent breakage and spread out force. The trade off is ease of removal and more filament used.
e) Enforced supports for stability: Consider enforcing supports on a stable part of the model to stabilise your support. This will spread any torque to the entire model. Trade off is any support residue on removal. - Speed
a) A key issue
b) Torque: Fast printing speeds create torque. This also might cause partially melted filament (see Bambu Wiki) which then drags the print. Once you achieve height, the torque becomes larger, making breakage or detachment more likely
c) Modifiers: Consider slowing speeds with a modifier over delicate parts of the print or globally slowing speed, especially sparse infill (often the fastest)
d) Layer Height: This is exacerbated with lower layer heights as the slicer increases the speeds and there is often less layer adhesion
i) Print speed is proportional to layer height so theoretically you should be able to go faster with lower layer heights but it doesn’t always pan out.
e) Melt Filament Index: Not all 3rd party filaments flow as fast as Bambu filament. BambuSlicer sets fairly high speeds (consider doing Max Volumetric Flow calibration in OrcaSlicer) - Temperature
a) Flow rate is also dependent on Temperature
b) Consider increasing temperature (consider temp tower via OrcaSlicer)
i) Trade is off is stringing, different finish etc. - Cooling
a) I am still learning about this
b) Strength: Less cooling means stronger parts. First layers are often not cooled. Most default BambuSlicer profiles involve significant cooling, particularly with the Aux Fan on.
i) I have used third party profiles successfully with the aux fan completely off
c) However, more cooling means better quality (geometric accuracy).
d) So for high-detail prints, you may want to err on the side of more cooling. - Infill
a) This is directly out of the Bambu Wiki
b) Avoid Grid and Triangle which involve crossing within the single layer and may cause the nozzle to scratch the infill.
c) Rather try rectilinear, gyroid or concentric infill