How to Fix 10 Most Common FFF 3D Printing Problems!
You load the filament into your FFF printer, like a Markforged Onyx Pro. You adjust the settings, prepare your STL file, and hit print — only to pull a deformed chunk of plastic out of the printing chamber. That’s when …
You load the filament into your FFF printer, like a Markforged Onyx Pro. You adjust the settings, prepare your STL file, and hit print — only to pull a deformed chunk of plastic out of the printing chamber. That’s when it’s time to troubleshoot your 3D printing problems.
Anything from slightly wrong settings to total printer breakdown can cause print runs to fail in the most fascinating and frustrating ways. And that’s without even mentioning the issues inherent to specific 3D printing technologies. Fortunately, we’ve developed a good understanding of the most prominent 3D printing problems over the years.
Let’s take a look at FFF 3D printing and how you can fix its most common printer issues.
1) The Printer Isn’t Printing
You know you’ve adjusted all your settings correctly, your print file is properly sliced and prepared, but still nothing appears on the print platform. In this case, you’re most likely dealing with one of two scenarios.
The first one is luckily the easiest to resolve — your printer may simply be out of filament. Some FFF printers have conveniently transparent spool casings, but others enclose the material in opaque compartments. If your printer is indeed out of material, simply load in a new spool and get back to printing.
Another possibility is that leftover materials from previous prints has clogged your printer nozzle. To fix the issue, you need a blunt needle or a thin piece of wire. Set your printer to heat up the nozzle to an appropriate temperature to melt the stuck material, and then carefully scrape the nozzle with the needle to clear the clog.
Warping is one of the most common problems with 3D printing. Warped parts will curl slightly upwards at the edges, detaching from the print platform. Some filaments, like ABS and PLA, shrink slightly as they cool, causing this issue.
The are multiple ways to fix this issue. You can purchase a heated print platform and set its temperature to just below your material’s melting point. This allows the plastic to cool slower, reducing the chance of warping.
You could also spread a small amount of glue or another adhesive on the print platform before starting the print run. This will fix the part to the platform, preventing it from curling. As a downside, you have to carefully detach the finished part and clean the platform afterwards.
Finally, incorrect print platform calibration can lead to warping. To re-level your platform, run your printer’s calibration tool to ensure the platform is perfectly level.
3) Cracked Prints
Cracking — also known as scarring or delamination — happens when the print layers begin to detach from each other. As a result, you’ll notice visible, or even large, cracks in the part’s surface. This is caused by uneven cooling speed of the print layers, and as such it’s a problem particularly with large parts.
The easiest way to fix the problem is to slightly increase the nozzle temperature. This allows the material to adhere to the earlier layers properly before it starts cooling. You may also want to check your printer fan speed to ensure they’re not cooling the part down too fast.
Your printer may begin to leave unwelcome strings or hairs of melted material between two different locations of the print. This happens when melted filament leaks out of the nozzle, leaving a residual string across open areas. The strings are a hassle to clean up and can negatively impact your part’s surface quality.
The main solution to stringing is to enable retraction on your printer through your slicing software. This will make the printer pull the filament backwards as the nozzle moves, preventing leakage. As an added bonus, refraction can boost your print speed
Another common solution is to reduce your nozzle’s travel speed. The slower speed allows the nozzle to properly empty itself before moving to another location.
Z-wobble sounds like something out of Star Trek, but it’s a relatively common 3D printing issue. This problem manifests as inconsistent wall alignments, causing certain layers to protrude out of what’s supposed to be a smooth surface.
In almost all cases, consistent Z-wobble stems from structural failures in your printer’s construction. This can be a difficult issue to resolve without manufacturer maintenance. You can try tightening the screws on the couplers that connect that connect the Z-axis motors to the spindles.
If Z-wobbles appears only occasionally, it may indicate an extrusion problem. In this case, you can try tweaking nozzle travel speed, print temperature, or other settings.
6) Elephant’s Foot
Elephant’s foot is a form of warping where the lowest layers of the print expand outwards. This creates noticeable bulges at the bottom of the part. This problem is usually caused by the nozzle being too close to the bed or the platform temperature being too high.
If the nozzle is too close, it will flatten the first layers and expand them horizontally. You can fix this issue by re-leveling the print platform. In case the platform is too warm, simply lower its temperature in your printer software.
7) Layer Shifting
Layer shifting happens when the nozzle misplaces itself along an axis, either the X- or Y-axis — or both. As a result, layers in the print get misaligned. While this can produce some interesting pieces, needless to say it will ruin your print.
Like Z-wobble, layer shifting is generally caused by mechanical problems. It could that some of your belt’s teeth are broken, the motors don’t get enough power, or the motors or drivers run too hot.
How you can fix these issues depends on your printer. You may have to replace some components, increase motor voltage, or install additional fans to keep your machine cool.
8) Melted or Deformed Prints
Every printer operator has at least once pulled a part out of their FFF printer and found it to resemble melted wax. This 3D printing problem stems practically always from an overheated nozzle. As the nozzle runs too hot, it causes the material to melt over and over again until it sloughs off the part.
The solution is to reduce nozzle temperature in your printer’s settings. You should also check your material’s properties to find the appropriate printing temperature.
9) Under- or Over-Extrusion
Under- and over-extrusion manifest in different ways, but are caused by the same issue. If your printer under-extrudes, you will notice visible gaps in the print. Over-extrusion, on the other hand, results in excess material packing over the sides of the print, ruining detail and surface quality.
The solution to both of these 3D printing problems is to check your printer’s extrusion multiplier and flow settings. Set these settings either higher or lower, depending which issue you’re facing. An incorrect nozzle temperature could also impact the flow of material.
10) Bad Infill
Creating infills is a manufacturing benefits unique to 3D printing. However, you may occasionally notice that your part’s internal structure is either missing or incorrectly printed. This problem often presents itself as a messy and weak infill structure.
There are may factors that can cause bad infills, but the most common is incorrect infill settings. Check your infill density and infill pattern in your slicer settings. An infill density of about 20% will generally work, but larger parts may require higher densities.
Printing at high speeds can also cause infills to fail. Here, the solution is to lower the print speed to give your printer sufficient time to create a strong internal support structure.