The correct answer is D. Raise the filament flow amount.
Filament flow amount, also known as extrusion multiplier or flow rate, is the setting that controls how much filament is extruded by the nozzle during 3D printing. It is usually expressed as a percentage of the default value, which is 100%. Increasing the filament flow amount means extruding more filament than usual, while decreasing it means extruding less1.
The filament flow amount can affect the quality and adhesion of the first layer, which is crucial for a successful 3D print. If the filament flow amount is too low, the nozzle may not extrude enough filament to fill the gaps between the lines and create a smooth and solid first layer. This can result in poor adhesion, curling, warping, or detachment of the print from the bed12.
To improve adherence on the first layer, the user should raise the filament flow amount slightly, such as 105% or 110%, to ensure that enough filament is extruded to create a strong bond with the bed. The user should also make sure that the nozzle height, bed leveling, and bed temperature are properly calibrated for optimal first layer adhesion12.
The other options are less likely to improve adherence on the first layer, because:
•Lowering the print bed temperature may reduce the adhesion of the TPU filament to the bed, as TPU usually requires a bed temperature between 20-60°C for the best results3. Lowering the bed temperature may also increase the risk of warping or curling of the print4.
•Adjusting the RPM of the cooling fan may not have a significant effect on the first layer adhesion, as cooling fans are not required with TPU3. In fact, using a cooling fan with TPU may cause cracking or delamination of the print, as TPU needs to cool down slowly and evenly4.
•Increasing the print speed may worsen the first layer adhesion, as TPU is a flexible and elastic filament that needs to be printed slowly and consistently. A recommended print speed for TPU is 15-30mm/s3. Increasing the print speed may cause clogging, stringing, blobs, or under-extrusion of the filament4.
For more information and tips on how to 3D print TPU filament like a pro, you can visit these links:
•How to 3D Print TPU Filament Like a Pro – Ultimate Guide & FAQ
•The Complete TPU Filament 3D Printing Guide - 3DSourced
•TPU Filament 3D Printing Material – The Complete Guide
•TPU filament - learn everything about the TPU material for 3D printing