3D printing is one of the easiest manufacturing processes with wide industrial and domestic applications. However, it also has its problems. Out of all the problems it has, one very special is ghosting. Ghosting is very common, seeing that many people using 3D printing encounter the problem during their operations.
Even though it is very common, the interesting part is that there are simple solutions to the problem. In a bid to help with that, this article will introduce ghosting, its causes, and solutions that work to fix the problem.
What is Ghosting or Jerking?
3D printing works to produce a unique product with strict adherence to the design. However, with ghosting, the story changes.
The simplest definition you can give ghosting is that it is the appearance of structures or features not included in the original design. With ghosting, you will notice the appearance of duplicates patterns on your model. Therefore, when you view your object at a particular angle, you will notice the repeating lines or features.
Ghosting goes by many names such as jerking, ringing, echoing, and rippling. Its uniqueness is that it only affects some parts of your prints. Therefore, some parts are perfect, while others will look bad.
Ghosting occurs as a result of many factors, and you can easily detect its presence. Here, you will know how to detect it, its causes, and how to fix the problem.
How to Detect Ghosting?
It is easy to detect when you are experiencing ghosting in your 3D printing process. There are two methods ideal for such purpose. One is through physical examination of the 3D prints. However, this method is not ideal because it is unreliable and needs you to complete the printing process before the full examination.
The second method is to download the Ghosting test from Thingiverse. It operates under the following:
- Test both PLA and ABS at varied temperatures
- Hot extrusion means that the hotter the extrusion, the more liquid it will be so the vibration blemishes will be more prominent.
- Mind the X and Y orientation when you are slicing the 3D model design.
What Causes Ghosting?
You would have been familiar with what causes ghosting seeing as the process is common. Ghosting occurs majorly due to errors in the 3D printer settings. You can understand what causes the problem by understanding vibration. Vibration leads to inconsistency of the 3D printer leading to irregular lines and features.
An increase in vibration, which can lead to ghosting, is caused by the following:
- Printing at a very high speed
- Using a 3D printer with very high acceleration and jerk settings
- High momentum generated by heavy components
- 3D printer base not providing enough frame rigidity
- Design incorporating rapid and sharp angle changes.
- Precise details such as wording or logos
- Quick movements leading to the generation of resonant frequencies
While it depends on the 3D printer, major parts of your 3D printer (extruder, metal parts, fans, etc.) are heavy. Therefore, fast movements of the printer will lead to inertia. With different movement combinations, speed, and change in direction, a 3D printer's weight can lead to what we call "loose movements."
Also, a quick change in direction during the printing process can lead to bending or flexing the frame. If such quick movements are intense, it can lead to "artifacts."
The mechanism of 3D printing is such that they build up an object layer by layer. Therefore, any vibration generated due to the quick movements will lead to inaccuracies in your prints.
Possible Solutions For Ghosting
Removing ghosting comes with understanding the causes of the problem. From there, you can tailor a solution/s that will work for your 3D printer. Below are a few solutions to try out.
Reducing the Printing Speed
Reducing the printing speed should be on the top of your to-do list to tackle ghosting. This is because it is easy and safe. However, when used, you have to deal with having slower prints.
Reducing the printing speed is a suitable solution because it reduces the moment of inertia. In 3D printing, having a design that has sharp and sudden angles has a high chance of causing vibrations. This is because the print head will have to make a sudden movement to cover such a requirement. Imagine the print head approaching such a sharp angle with high speed. No doubt it will result in the print head having to trouble slow down. Also, an increase in speed will lead to more vibration, which contributes directly to ghosting.
When you print at high speed with a sudden change in direction, it can lead to severe ghosting. However, reducing print speed can solve the problem.
Reducing printing speed is ideal. However, it can lead to the nozzle spending more time in sharp angles. This will lead to over-extrusion and bulging.
Acceleration and Jerk settings
Acceleration and jerk values are two things you should always note when striving for quality in a 3D printer. On the one hand, acceleration value is how fast the printing speed changes. On the other hand, jerk value is how the acceleration change. The two values are important and responsible for the movement of the printer.
Like we said under the causes of ghosting, a high acceleration value leads to ghosting. Therefore, the right thing is to reduce its value. When you reduce the acceleration value, you reduce the printing speed. This, in turn, reduces the moment of inertia.
A high jerk value can also lead to ghosting. This is because the printing head will make a quick and sudden movement in the required directions. In order to combat this, you should lower the jerk value, which will give the print head time to settle.
Reducing the acceleration and jerk value is ideal for reducing vibration and ultimately ghosting. However, there is a downside to it. A very low jerk value can result in unnecessary details on the product because the nozzle is staying too long on the project. It can also lead to over-extrusion at the sharp corners.
Physical examination of the 3D printer can help you know whether rigidity is the cause of the problem. You can hold a component of the printer to see whether it wobbles. If it does, what you are experiencing is as a result of rigidity.
You can make sure every component of your 3D printer is rigid by using these techniques:
- Add braces for triangulation purpose.
- Add materials such as foam and rubber around your 3D printer for shock mounting.
- Make use of a firm/solid base for your 3D printer.
- Use an Anti-vibration pad with your 3D printer.
- Use a high-quality table as a surface foundation to print on.
- Use stiffer springs to reduce the bounce.
With the above techniques, you should be able to remove or absorb the vibration generated by the 3D printer. If you could, you will have a quiet operation with guaranteed success.
3D Printer Component Weights and Location
There are two ways you can tacking ghosting/vibration when looking at the weight of a 3D printer's components. You can make the components light, such that they need only small energy to move and generate less energy. You can also make sure that the components are very heavy such that they will need very high energy to make them vibrate.
Also, you should not mount the filament on the top of your printer. Instead, it would help if you placed it in a separate spool holder. Another option you can try is to get a light extruder. If you have a 3D printer with dual extruder, you can remove one to lighten the weight.
Tight Loose belts
If you have a 3D printer with a slack motion system, you have a high chance of experiencing vibration synonymous to ghosting.
A slack motion system is majorly due to using a loose belt. This leads to a reduction in the printer's precision in terms of movement, leading to vibration. This is because a loose belt will make the print head move around more.
You can check whether the cause of ghosting in your printer is a loose belt by checking whether it is tight and makes a low/deep sound when you pluck it. If the cause of the problem is the belt, you can tighten them using the instruction giving by your 3D printer's manufacturer.
Ghosting can be a very annoying problem, especially for those just getting to know 3D printing. It is a common problem that leads to having unnecessary details on a 3D print due to vibration. Eliminating the problem can be very difficult. This is because many factors cause it. However, when you know the causes, it is easy to find the right solution.
In order to make things easier, this article discussed ghosting. It introduced the causes of the problem and how to test it. Most importantly, it discussed how to fix ghosting in your 3D prints. While each solution is unique, you should know that sometimes, you might need to combine the solution. With ghosting remove and other things in check, you will have joy producing 3D prints of high quality