WHAT’S THE ISSUE?
After finishing a model with some support, you remove the support structure, but they could not be moved completely. Small filament will remain on the surface of the print. If you try to polish the print and remove the remaining material, the overall effect of the model will be destroyed.
∙ Supports Not Appropriate
∙ Layer Height
∙ Support Separation
∙ Rough Support Finishing
Supports Not Appropriate
Support is an important part of FDM printing. But some models don’t need any support with a little adjustment. If you have to, the design of support has a great influence on the surface of the print.
CHECK SUPPORT PLACEMENT
Most slicing software can choose two ways to add support: “Everywhere” or “Touching the Build Plate”. For most models, “Touching the Build Plate” is sufficient. “Everywhere” will let the print be full of support, which means the surface of the model will be roughly caused of support.
CHECK THE CAPABILITY OF YOUR PRINTER
Sometimes the model does not need support because the printer can print a gap and relatively steep angles. Most printers can print bridging gaps of 50mm and printing angle of 50° perfectly. Create or download a text model to print to familiarize your printer with the true capability.
ADJUST THE SUPPORT PATTERN
Choose the different style of support to match the different types of models so that can obtain a better support-model interface. Try switching “Grid”, “Zig Zag”, “Triangle” and so on.
REDUCE SUPPORT DENSITY
In the slicing software, switch the view to “Preview”, and you can see the supporting structure. Generally, the support density is the default. You can appropriately reduce the support density and then fine-tune the printer. Try to use 5% density to see if the support surface of the model improved.
The size of the layer height determines the slope of the overhangs part that can be printed. The thinner the layer height, the greater the slope.
Lower Your Layer Height
Lowering the layer height can greatly improve the overhangs parts printed. If the layer height is 0.2mm, support is required for any overhang part over 45°. But if you reduce the layer height to 0.1mm, it is possible to print a 60° overhang. This can reduce the support printing and save time, while the surface of the model looks smoother.
Creating a removable support structure needs to balance the strength of the support and the difficulty of removal. The support surface may be horrible if you create easily removable support.
Vertical Separation Layers
Some slice software like Simplify 3D can set the separation to find a better balance between different factors. Check the “Upper Vertical Separation Layers” setting, adjust the empty layer numbers, generally set 1-2 vertical separations layers.
Horizontal Part Offset
The next checking is the Horizontal Offset. This setting keeps the left-right distance between the print and the support structures. So, the vertical separation layers avoid the support sticking to the print while the horizontal offset avoids the side of the support sticking to the side of the model. Generally, set the offset value of 0.20-0.4mm, but you need to adjust the value according to the actual work.
Rough Support Finishing
If the support structure is printed too roughly, the print quality of the support surface will also be affected.
REDUCE PRINT TEMPERATURE
Check the filament temperature range and adjust the nozzle temperature to the minimum for the filament. This may result in a weak bond, but will also make the support easier to remove.
USE ABS INSTEAD OF PLA
For the models that has added support, there has a big thing with the material when doing some process such as polishing. Compare with PLA which is more brittle, ABS is easier to work. So choosing ABS may be better.
DUAL EXTRUSION & SOLUBLE SUPPORT MATERIALS
This method is relatively more expensive. If most of your print needs complex support, then a dual extrusion printer is a good choice. Water-soluble support material (such as PVA) can achieve the complex support structure without ruining the print surface.