Beginner Guide Part 6: How to Improve 3D Print Quality

A great 3D print rewards you for investing your time and money. Check out these simple 3D printing tips to improve the quality of your 3D prints!

1. Level the Bed and Set the Nozzle Height

Nozzle height is very important.

The most fundimental way to improve the quality of the 3D print is to make sure that the bed is level and the nozzle distance is set properly. You can use a sheet of paper or feeler gauge to determine the distance between nozzle and bed. When the (clean) nozzle is the appropriate distance from the bed, the paper or gauge will have minimal resistance when pulled free. It will also go back underneath the nozzle without force.  Repeat this procedure two or three times to ensure that it is accurate.

2. Check Nozzle Temperature

A sign that the extruder temperature is too high

The temperature of the nozzle — or nozzles, if there are more than one — directly effects the appearence of the print. If the nozzle is too hot, it could leave strings of filament between separate parts. When building tall pieces, high temperatures melt the earlier layers, resulting in malformation.

When building taller prints, include a one-centimeter cube built on the opposite side of the build plate. This removes the hot nozzle from the print and allows time for cooling. If there are strings of filament between structures, use a wall or ooze shield structure, a common feature in slicer programs.

For tips on achieving the perfect temperature for PLA prints, check out this article. (The same is true for many other materials, too.)

3. Find the Sweet Spot for Your Bed Temperature

A case of

Controlling build plate (or bed) temperature helps with print adhesion. As the model prints, each layer shrinks as it cools. Thus each layer above the bed contracts, and the shrinking layers cause the edges of the print to pull away from the build plate. 

When the bed temperature is too high, the model may develop so-called “elephant feet”. This is an indication that you should slightly reduce the bed temperature for the next print.

4. Try Different Build Plates for Different Effects

A glass surface yields a shiny bottom surface.

Different build plates yield different textures on the bottom of the print. Bed materials like glass, PEI, or Kapton tape leave a smooth surface. Glue-on polycarbonate sheets or painter’s tape leave a matte finish.  

If using a spray or glue on the surface, use enough to stick to the print, but not so much that it leaves dents or malformation. Too much glue or spray makes it difficult to remove the print, too. Forcing it off could leave the print damaged or, if enough pressure is used, break or warp the plate.

Experiment to see which method not only works the best with your setup, but also leaves a finish that compliments the print.

5. Pay Attention to Printer Adjustment and Maintenance

Square all printer axes.

Each 3D printer has its own stand out features, and probably some things that need attention to improve print quality. For example, the Anet A6 and A8 are inexpensive printers that benefit from upgrading. A few of such upgrades are detailed in this article. It also contains advice that may help to find and correct the weak spots of other budget printers.

Optimizing your printer involves many smalls steps, like cleaning and lubricating the rails using manufacturer recommendations. If the printer has two stepper motors for the Z axis, make sure that the gantry is at the same height on each side.

Continuing, check to see if there is any sort of wobble anywhere in the frame. Ensure that the bolts are tight and that all 90-degree angles are square, and check the manufacturer’s website for updated firmware.

6. Treat Filament with Care

Moist ABS vs. dry ABS

Many filaments love water, absorbing it from the surrounding air. Exposed filament, especially ABS, nylon, and flexible materials, drink moisture in, resulting in problems.

Damp filament expands during extrusion as the water turns to steam and bubbles out of the plastic. The filament pops or crackles coming through the nozzle, and when observed closely, something that looks like smoke may be present. The biggest problem, however, is that the print will look rough when finished. 

Store spools in plastic bins with decessant between uses. In some cases, it is possible to dry the spool of filament in the oven over a few hours at very low temperatures. Building your own heated bin that feeds into your 3D printer is a fun and easy project!

7. Find a Slicer That You Like, and Learn It

Take time to learn a slicer.

Talking about 3D printing quality is impossible without mentioning slicers. A slicer is what converts a 3D model into instructions (G-code) that drive the printer. There are many, many out there, most of which are free. If the print isn’t as “neat” as it could be, then see if there is a “fine” or “hyper” quality setting. It will slow the print down a bit, but the results may be worth the wait.

Don’t jump to a different slicer when a few prints come out bumpy. Research the quality problem, then change one setting at a time. Print again and see if it helps. There are many settings, so here’s some hints to get you started.

Learning what settings do what will help improve quality, regardless of the slicer chosen.

8. Use Supports With Overhangs

Supports vary from slicer to slicer.

FDM 3D printers work by pushing out melted filament that bonds to the layer below it. When there is no layer below for it to bond with, then the slicer may try to bridge the overhang. If the bridge is too long, there will be sagging, or complete failure of the print. It takes a little research and experience to know how and when to use supports.

Note: When using supports, a bit of post processing (sanding, trimming) helps hide the attachment places. 

9. Close Gaps in Perimeters, Top, and Bottom Layers

Gaps sometimes appear between the perimeter and top layer.

When printing something with detail, small holes can appear around the top and sides. Quality issues along the sides might be helped by slowly increasing the amount that the perimeter overlaps the infill. With each small adjustment, try the print to see if it closes the gap.

If the speed is too high while producing infill, the extruded filament may not stay with the perimeter as the nozzle isn’t in location long enough for it to form a bond. In this case, reduce the print speed, but not too much, as other problems may arise.

Also, check out how much filament is being extruded. When changing this amount, do it with very small adjustments. Increase the rate by hundredths (.01) followed by a test print with each adjustment.

10. Adjust Z Axis Movement to Avoid Dragging

What happens when the nozzle drags across the previous layer

After getting the first layer to stick, there’s a line present where the nozzle drags across the surface or perimeter of the print. This might be caused by a lack of filament retraction. Simply adjust this setting to improve the print.  

Some slicers have the ability to instruct the printer to raise the height of the nozzle while travelling over empty spaces. See if this is included in the advanced settings of your slicer.

11. Slow down Print Speed to Avoid Ringing

Ringing appears almost like motion blur.

Ringing, or echoes around edges or around print features, reduce visual quality. These unsightly lines are caused by vibrations from movement of the extruder.

To fix the problem, reduce print speed. However, be sure that the extruder moves enough so that the pritned area doesn’t overheat and cause other quality problems.

12. Post Process for a Finished Look

Image of: 12. Post Process for a Finished Look

Removing supports or getting rid of small imperfections can be accomplished with a sharp hobby knife or sandpaper, especially if painting or polishing is in order.  

Some plastics, like ABS, work very well with an acetone vapor treatment. The result is a glossy finish, but does weaken the model as it dissolves the plastic, which is a chemical change.  

Composite plastics, like brass or copper infused, are improved with sanding and a special treatment to bring out a tarnished look. For example, Brasso makes brass have a worn look.