Resin printing comes with its own set of problems and challenges. So let’s cut straight to the chase and explore the most common reasons why your resin print failed and find the right solution.
Print Plate Adhesion Problems
Does your print fail to adhere? Is it floating in the tank or is it partially separated? Adhesion problems occur for several reasons.
First of all, the printer might be having trouble when positioning the next layer slightly differently on top of the previous layer. After a few repositioned layers there will be a higher force pulling away from one side and the printer can’t compensate.
If you’re using a top-down SLA printer, this force is exerted on the model whenever the plate is separated from the vat for repositioning. On the other hand, with bottom-up printers, you might have adhesion problems if the build plate wasn’t adequately prepared. In this case, a print will adhere well only when the plate is even or finely textured.
However, sometimes the temperature is the culprit. Either the resin isn’t at the correct temperature or it’s fluctuating during the printing process, thus having a negative impact on the resin’s properties.
To ensure plate adhesion, you need to go through several steps because it’s difficult to determine just one culprit:
- Check the temperature: In a lot of cases, the temperature is simply too low for the material to adhere to the plate. So check the temperature of the resin and heat it if necessary. Sometimes we only need a marginal difference and warming up the room temperature does the trick.
- Check the print’s position: If your resin printer has a tilting vat to help prevent peeling, there will be sections of the plate that are exposed to higher stress. In this case, you should reposition the print where the peeling force is at its minimum. This is especially important if you’re printing tall models.
- Level the bed or vat: If your printer doesn’t come with an automatic leveling system, you’ll have to manually level the vat. This is a common step that has to be taken when working with common FDM printers as well. So, if you notice a particular section of the print adhering to the plate then maybe that section isn’t correctly set inside the vat. Another clue is a flat piece of resin hardening on the interface layer once you finish printing. To fix this issue, you’ll have to examine your printer’s instructions or look for specific tutorials on how to calibrate the print bed or vat.
- Inspect the interface layer: Nowadays, most resin printers have a thin interface layer at the bottom of the vat. The cheaper bottom-up printers use the same concept by pushing a thin layer of resin at the start of the printing process. In either case, after several prints, you’ll encounter issues with the interface layer due to wear and tear. Take note that if you ignore this problem you will end up with a partially useless build plate because certain sections become unviable.
To fix this problem you have two choices. You can either replace the interface layer or purchase a new vat. Alternatively, you can establish which sections of the vat aren’t affected and print only in those areas. However, in the end, you’ll have no choice but two go with one of the two solutions.
- Clean the vat: After printing a few models you’ll start finding hard pieces of resin floating around. As more of them accumulate, they’ll get in the way of a successful print. So make sure to regularly check the vat after each print to filter any solids. In addition, you should also inspect the bottom of the vat where sometimes you’ll find sections of hardened resin.
- Mix the resin regularly: If you print once every few days, you have to mix the resin. If you don’t, the heavier compounds will sink to the bottom of the vat and you’ll end up with an inconsistent model.
- Add more texture to the plate: Some build plates have a very smooth surface that lowers the print’s adhesion. If nothing else works, you can lightly sand the build plate to give it some texture. Just make sure to thoroughly clean the plate afterward otherwise you will contaminate the resin.
Partial Print Separation
During the printing process, a piece of hard resin changes its position or separates itself completely, thus ruining a section of the print. When this happens, there’s usually an issue related to the vat. The highest possibility is that the model is not oriented correctly to fight the peel forces and this causes distortions. However, if the print is positioned properly, the problem might lie with the support structures and their strength.
Partial separation can lead to an unsuccessful print without a doubt, so let’s explore the following solutions:
- Secure the print station: As the printer works and new layers are constructed, the vibration can lead to small changes in the platform's position. This can lead to separated layers. So make sure to properly secure the platform so it doesn’t move.
- Improve the supports: The next step is to examine the supports and strengthen them as needed. Increase in small increments the width of the sections where the support interacts with the model. You can also add struts between them to improve structural integrity. Finally, you can always increase the number of supports. Just keep in mind that you’ll have to do some additional work removing them and post-processing the model.
- Add drainage holes: If you’re printing a large model, consider adding drainage holes if possible. If the surface area is also large, you can leave certain parts hollow on the inside. So, instead of enabling the print to unstick itself from the vat, you reduce the forces that act on it and therefore lower the risk of partial separation. Furthermore, when you print a large model you waste a lot of material by filling it too much on the inside.
Sometimes layers don’t bond well and the print becomes warped or frayed. Also known as delamination, this problem is often caused due to lacking proper orientation. The print sections that are separate from the section that’s adhered to the print bed can detach. When that happens, each new layer becomes a sloppy mess. This can be easily fixed by adding support to those sections that aren’t directly attached to the main body of the model.
Another cause is contamination. By not filtering or cleaning your vat correctly, there floating chunks of dry resin and other contaminants can lead to layer separation.
However, while usually layer separation occurs during the printing process due to the aforementioned causes, it can also occur during post-processing. When cleaning and refining your model by leaving it inside IPA, the layers can simply fall apart. This is caused by an already weakened print.
That being said, here’s what you can do to fix these problems:
- Use supports: Supports are often the answer. Whenever you print a model with difficult angles that aren’t connected to the main body, you should reinforce it with supports. Additionally, you should try out different print orientations to find the most optimal use of supports without creating too many.
- Check the laser: The laser needs to have a clear path at all times otherwise we can’t have a successful print. Sometimes layer separation is caused due to a partially obstructed beam that can’t properly hit the resin.
Start by inspecting the resin. It should be clean from any contaminants. Filter it to remove any possible debris, such as tiny fragments of dry resin. You should also mix the resin, especially if you haven’t printed anything in days. Next, you need to take a look at the interface layer and check for any signs of ghosting. After multiple prints, you will without a doubt see some signs of wear and tear, but the interface layer becomes a problem when the damage is enough to reduce the laser’s effectiveness. If this is the root of the problem, you’ll have to replace the layer, or perhaps even the vat.
- Go easy with the IPA: Isopropyl alcohol, or IPA, is a key element in the resin printing process. We need it as a wash solution during the post-process cycle. However, if we leave the print in the IPA bath for too long, the already weak layers will start separating themselves. To avoid that from happening, you should wash your models as quickly as possible. It doesn’t take much time for any unset resin to be removed by the alcohol.
So the print came out in one piece, but it looks absolutely terrible? You might be experiencing a case of ragging.
This aesthetic printing problem is caused by resin flakes and partially hardened horizontal shelves that protrude from the model. The result is a bad finish with unwanted sections that might even detach themselves from the model during the printing process.
Ragging is normally caused by a partially blocked or diffused optical path. In other words, the laser spreads too much outside of the area where the resin should be settled. Anything that comes in between the material and the beam can cause this. So, here’s what you can do to prevent prints that develop unordinary resin flaps, disks, and other structures:
- Examine the optical path: The laser is protected by a transparent barrier that can get dirty with time. You should regularly inspect it for any dirt, fingerprints, dust, and anything else that can diffuse the laser beam and reduce its effectiveness.
- Filter the resin: Keeping out any foreign particles from the resin will solve a lot of problems, including ragging. So make sure to filter the resin regularly to avoid any contaminants and small solidified pieces of resin.
- Mix the resin: Remember that certain compounds in the resin are heavier than others and will settle on the bottom of the vat after a while. This is especially the case if you use your printer only once every few days. Mix and remix your resin regularly to prevent ragging any other issues that lead to an unsuccessful print.
If you already made the switch from FDM to resin printing, you need to prepare yourself for a new set of challenges. Some of them will be familiar, others will require new solutions and more creativity on your part. Just keep in mind that where there’s a will there’s a way. This list presents some of the most common issues you’re likely to come across, so go through the troubleshooting process step by step to understand what to look out for.