FDM 3D Printing & Associated Issues
FDM 3D printing is the most common type of 3D printing technology out there. It is widely popular due to its affordability, availability of cheap materials, and ease of use. While all these factors add to its overall acceptability, it also relies a lot on trial-and-error methodology for getting successful results. Even though this can be eliminated by carefully understanding the 3D printer, the material, the software, and the entire integrated system as a whole, it still is a bit rusty in the early learning period.
Almost all FDM 3D printer users have to face most of the same problems, no matter how much they try to avoid them. But it is a fun journey to learn the technology. Once users get a hang of the technology it opens doors to a valuable asset.
As mentioned above, FDM comes with its fair share of operational problems. So, before we move on to the core topic, we would like to know if you face or have ever faced the below issues while 3D printing?
FDM Issues
First Layer Adhesion Problems: These are the problems associated with getting the first layer of the print to stick to the build plate. The adhesion is not sufficient and in mid-print, the first layer loses grip on the build plate and it slides away resulting in a print failure. This is a common and the most widely encountered problem in FDM 3D printing.
Question: Have you ever faced this issue?
Nozzle Clogging: Nozzle clogging is a problem when the nozzle is not able to dispense material as a bulk amount of material gets stuck at its opening due to various reasons. Nozzle clogging simply means that the software will continue to run the code and so the nozzle travel will always be empty and no material will be deposited. Thus, leading to a gap in layers and failed prints. This is also frequently observed during FDM printing.
Question: Have you ever faced this issue?
Uneven Material Deposition: It means that the material deposited onto the build plate will be different at different points on the same layer. At some points, the material deposition will be normal, while at others it will be less.
Question: Have you ever faced this issue?
Gap lines across build surface: Gap lines are those lines where the material is missing. Gap lines are easy to identify and spot when printing a flat surface and gaps can be easily visible on the same layer.
Question: Have you ever faced this issue?
Need for a Level Bed
If you answered ‘Yes’ to even one of the above issues, then it is safe to assume that you are facing one of the most dreaded issues associated with FDM 3D printing and that is bed leveling. All the above-mentioned problems occur due to poor bed leveling. The bed may be slanted at certain angles due to the faulty adjustments of the leveling screws on the printer. While the bed may seem completely level to the naked eye, even a slight slant in the angle can affect and ruin the print. Therefore, it is necessary to keep a level bed before starting a print job. Without this humble setting, you will put the entire print at risk.
How to Level a Bed?
Leveling a bed, as mentioned earlier, is one of the most dreaded tasks any user has to perform. It requires a lot of patience and careful attention to get it right. A bed can be leveled in two ways – Difficult way and Simple way. We will first explore the difficult way. The difficult way is the manual process of leveling the bed.
Manual Bed Leveling
The bed, also known as the build plate or build surface should be checked for leveling every time the 3D printer is started after a significant stoppage of operations. It is not necessarily required to be checked for every print. But if the printer is not in use for a few days, and when you start the printer, then it should be checked and tested before starting an important print.
Let us see the tools required for manual bed leveling.
Paper: It is one of the most basic things required to check the gap between the nozzle and the bed. You should be able to comfortably slide a piece of paper between the nozzle and the bed. Preferably use a smooth visiting card.
Screws: The bed is adjusted in the Z-direction by turning four screws placed around the edges of the bed. Turning these screws slightly will adjust the bed. By placing d sliding the paper between the nozzle and bed, the gap can be optimized for each point.
Scraper: A scraper is an important tool that is used to scrape off print remnants from the bed. But a scraper can also scratch the bed surface and so the scraping should be done carefully.
Dish Soap and Cotton Cloth: Sometimes the residue strongly sticks to the bed and so it needs to be washed off using dish soap and then cleaned with a cotton cloth.
Isopropyl Alcohol: Isopropyl Alcohol helps in efficiently cleaning the build plate. It is a good solution to use on most plates but it is also recommended to ensure that the plate will not be adversely affected by it.
Auto Bed Leveling (ABL)
As the name suggests, Auto bed leveling (ABL) is the automatic leveling of the bed for the printing process. It is an easy way to level a print bed. It eliminates the need for manual checks. It improves printing quality and bed adhesion by measuring the bed surface and then adjusting all movement to follow the tilt or contours of the bed. Most beds appear flat and even, but there may be irregularities on the surface due to tape or other print residues. Alternatively, mechanical flaws may cause irregularities in the bed or nozzle height. All of these height irregularities can be compensated for by auto bed leveling.
The BLTouch probe, which emulates a servo but uses a retractable pin, is the most popular sensor. There are infrared and inductive probes that activate at a predetermined distance from the bed.
Types of Auto Bed Leveling
There are three types of auto bed leveling methods:
Three-Point: In this method the probe considers three arbitrary points to probe and apply a matrix to the bed’s overall tilt to determine the evenness of the bed.
Planar Grid: The sensor in this method probes the bed in the form of a grid and again applies a matrix to the bed’s overall tilt to determine the evenness of the bed.
Bilinear Grid: In this method, the sensor probes the bed in a grid but applies a mesh-based compensation to level the bed. This kind of method is good for an irregular bed.
How Auto Bed Leveling Works
Nowadays, most FDM 3D printers come with an auto bed leveling feature. Earlier this was a premium feature available only in the high-end desktop models but as the competition in the lower segment got feisty, the feature trickled down to most affordable printers as well.
The 3D printer uses a proximity or a contact limit sensor generally fitted close to the nozzle to help in the bed leveling.
Once the auto bed leveling process is initiated, the sensor checks up on different points on the bed to calculate the distance between the nozzle and the print bed. At each of these points, it continuously notes data. This data is then used by the printer to calculate the height or the distance between the bed and the nozzle at each of the points to adjust the nozzle height for printing at that specific point. This means that if the print bed has an irregular surface, then the firmware makes small adjustments to the Z-axis during the printing process. The whole idea is to ensure that the nozzle is always at an optimum distance from the bed surface and this must ideally be a constant distance for every point on the bed.
Difference Between Manual Bed Leveling and Auto Bed Leveling
Disadvantages of Auto Bed Leveling
- The sensors responsible for automatic print bed leveling make the print head heavier.
- Assembling an automatically calibrating 3D printer kit can be a difficult task.
- The assembly may disturb the print head and cause calibration errors in printing.
- The 3D printer's firmware may contain mechanical errors or a faulty design, making it impossible to achieve an evenly configured print bed.
Three Popular 3D Printers with Built-In Automatic Print Bed Leveling
To help our readers to make a buying decision, we share three affordable and popular 3D printers with auto bed leveling features.
Ender 5 Plus
The Ender 5 Plus, from Creality, is an upgrade over its predecessor, the Ender 5. This 3D printer boasts a larger build volume. The design is also more streamlined than most of the other printers from Creality. The filament spool and the control box also is designed to fit inside the gantry. So the footprint of the printer does not exceed the gantry dimensions.
Ender 5 Plus comes semi-assembled, making it simple and quick to set up. Users who do not want to waste time assembling the machine will appreciate this design. The print quality is good, the feature integration is excellent, and is easy to operate.
The Auto Bed Leveling feature is one of the most important features in the Ender 5 Plus. It comes with a BL Touch sensor pre-installed. Users simply plug it in and begin printing. The auto bed leveling system can precisely measure bed surface tilt and compensate for it in the Z-axis. It offers a dependable bed leveling operation and so users need not be concerned if the build platform is uneven, the prints will always come out perfect.
Specifications:
- Build Volume: 350x350x400 mm
- Max. Extruder Temperature: 260 °C
- Max. Heated Bed Temperature: 110 °C
- Bed Leveling: Automatic
- Heated Platform: Yes
- Market Price: Approx. $580
Anet ET5
For its price, the Anet ET5 has a relatively large build volume. It is open in design, with only two rails serving as a body. It has a simple design, but this has little effect on the print quality. Unlike many other printers, the control box is located beneath the bed, saving space.
The Anet ET5 is packed with multiple useful and interesting features such as filament detection, filament control, print resume, touch screen, and an excellent auto bed leveling feature. All of these features save users time spent on unproductive tasks and allow them to concentrate on critical issues.
The auto bed leveling feature is a lifesaver for beginners who do not know or have the experience to manually level a bed. This is one of the most affordable 3D printers with auto-leveling.
Specifications:
- Build Volume: 300*300*400 mm
- Max. Extruder Temperature: 250 °C
- Max. Heated Bed Temperature: 100 °C
- Bed Leveling: Automatic
- Heated Platform: Yes
- Market Price: Approx. $400
Original Prusa i3 MK3S+
The MK3S+ is an improved version of the MKS3 with some notable features. The MKS3+ includes a SuperPINDA probe for improved first layer calibration, as well as high-quality Misumi bearings and other useful design changes. Prusa has ensured that the print quality and experience remain consistent with its earlier printers, so users know what to expect from the printer.
The printer is typically sold as a DIY kit, which is fairly simple to assemble thanks to guiding videos posted on social media and an active and thriving online community. The printer includes features such as simple slicer software, a filament sensor, and crash detection. Diligent software and firmware updates improve the printer even more by removing bugs, improving existing features, and even adding new ones.
The SuperPINDA probe aids in auto bed leveling, ensuring that each print is successful. The MK3S+ probes the bed in several places before each print, creating a virtual heightmap of the print area. This procedure ensures that the first layer of the print is always flawless.
Specifications:
- Build Volume: 250 x 210 x 210 mm
- Max. Extruder Temperature: 300 °C
- Max. Heated Bed Temperature: 120 °C
- Bed Leveling: Automatic
- Heated Platform: Yes
- Market Price: Approx. $749
Common FAQs
What does Auto bed leveling do?
An auto bed leveling measures the unevenness of the print bed of a 3D printer through several points on the bed. This data is then used by the firmware to compensate for the unevenness in the Z-direction through the nozzle so that the nozzle prints as if the bed is evenly flat at all places.
Can auto bed leveling work without a sensor?
It is a common question to ask if the bed can be leveled without a probe or a sensor. The simple answer is yes. This method can be called semi-auto bed leveling. This can be achieved if you are using MARLIN firmware. The firmware allows the users to send a G29 code repeatedly once for each point on the bed until all points have been measured. The rest of the points lying in-between these points must then be adjusted manually with the manual bed leveling method.
