6 Reasons Your Resin Prints Don’t Stick And How To Fix Them


One of the most frustrating problems I have had is trying to get my 3D print in my SLA resin printer to stick to the build plate.

There are 6 main reasons that your resin print is not adhering to the build plate.

While going through this process of troubleshooting, have a small quick print that you can quickly run to check if the problem is resolved.

The Print Surface Area Is Not Big Enough

One of the simplest ways to get prints to adhere is to ensure that the print has enough surface area contact with the build plate.

If you have a bunch of supports that barely touch the build  platform that attach to a larger model, the large areas of the model could hold tighter to the FEP than the supports do to the platform.

The solution is to use a raft in those cases. A raft increases the surface area that is touching the build platform much in the same way a raft works for FDM printing.

If the raft succeeds in sticking to the platform but the model comes off the raft, you will want to increase the size of the supports you are using. Thicker supports will hold stronger to the raft.

Also, make sure there is plenty of supports as well to improve the hold.

Your Build Platform Is Not Properly Aligned

One of the most important actions needed to insure a successful print is to properly align you build platform.

If the platform is misaligned, you could prints fail to adhere on one side or another. This is a good indicator that you need a realignment.

Different printers have different alignment instructions. Check your user manual for clear instructions. Here is a list of popular printers with links to the the support pages where you can download a digital copy of the user manual.

Anycubic PhotonSupport Page
Anycubic Photon Mono SeriesSupport Page
Monoprice Mini SLAManual
Phozen Sonic 4K, Mini 4K, and XL 4KManuals
Elegoo Line of Resin PrintersSupport Pages

The manuals will recommend sticking a piece of paper under the build platform to ensure it is tight. I recommend placing pieces of paper under each corner of the platform to ensure that the platform is tight all around it.

Once your platform is properly aligned, the next thing to check is your exposure times.

Your Exposure Times Are Too Low

In order to get the bet chance of adhering, the cure time settings for your first layers need to be high enough.

The first layers need to grip the build platform more than they grip the FEP film.

Times for the first layers are significantly longer than regular exposure time, often as much as 5 times longer. This gives the little bit of resin squished between the FEP and the build platform time to harden and build a strong bond.

Usually 4-8 layers are needed at these higher exposure times. Multiple layers are required as the platform will be extremely close to the film and there may be very little resin in the first layer or 2.

Check the recommended setting from the manufacturer of the resin. Make sure that the number of bottom layers and the bottom layer exposure time match the recommendation.

There are recommended settings from the community for different resin types. These setting are calibrated specifically for the Anycubic Photon.

If you cannot find numbers from the manufacturer or the number they provide are not working properly, you can do a calibration test to determine the best settings for your resin.

One word of caution, some colors of resins need longer exposure times because the pigments are absorbing some of the light. The best color of resin to use is grey, which is the most common color to use to show off models online.

Now that you have a properly aligned build platform and have your exposure times set, the next thing to check is issues with the resin itself.

You Have Resin Related Issues

Sometimes the problem comes down to the resin itself.

Some resins are designed for thinner layers. These resins should clearly disclose that they are for super-thin layers. When you print with these resins, you will need to make sure to reduce layer size.

Another resin related issue is pigment settling. Pigments give the resin its color but they can settle to the bottom of the print vat or bottle.

It is not necessarily obvious that pigment has settled to the bottom of the vat. Just a little bit of settling can interfere with print adhesion.

The best way to deal with settled pigment is to mix up the resin in the vat before printing. Take your scraper and gently mix the resin.

Be careful not to scratch the FEP film when mixing the resin. If you scratch the film, it will need to be replaced.

Now that you have a perfectly aligned platform, your settings are calibrated, and you have properly mixed your resin to avoid issues with settled pigments, the last thing to check is the platform itself.

The Print Is Sticking To The FEP

If the printer is correctly set up and the print setting are correct, the problem may be that the print is sticking to the FEP film.

If prints are sticky to the bottom of the vat, check the FEP film. Make sure that the FEP film is not damaged. If there are any scratches or creases in the film, the print may have a stronger hold on the FEP than the build plate.

PTFE lubricant can also be used reduce the stickiness of the FEP fill. Empty the resin vat and clean it very well with 95%+ IPA. Once the film is dry, apply the lubricant very liberally on the film with a clean cloth, being sure to get it into all the edges and corners. Allow the vat to dry before adding resin.

Too Much Vacuum Pressure On Platform

The last place to check is the build platform itself. The process of pulling the plate off of the FEP film as each layer is printed creates vacuum pressure. If this pressure is not overcome, the print can pull off the build plate.

You can reduce the force of the vacuum on the first layers by slowing down the speed on the first layers. The slower speed allows the resin in the vat time to flow underneath the print and reduce the pressure pulling down. This is especially important on those first few layers where the entire build plate has to pull up off the FEP.

Smaller platforms can also reduce the pull on the first layers. This might not be an option for all printers, but if you can get a smaller platform you can reduce the vacuum pressure on the first layers.

Coat the bottom of the build platform with some resin before lowering the it into the resin. This avoids the possibility that air gets trapped below the platform.

After you finish printing, don’t completely clean the build platform. If you leave the platform a little bit sticky from the previous print, it will help the next print adhere. To be clear, remove all of the cured resin off the plate just leave some of the sticky uncured resin to help the next print stick.

Another option is to use an anodized aluminum build platform. Prints adhere better to anodized aluminum.

More Extreme Options

More extreme measures can also be used to increase the grip on the build plate. These include sanding the build plate to increase surface area. Use very fine grit sand paper. The first layers cure into the scratches from the sand paper, increasing their hold.

Other extreme options include putting tiny holes or channels into the platform. You want to make sure to keep the holes and channels small to ensure they don’t cause more issues.

Conclusion

Failed prints are one of the more frustrating aspects of 3D printing. And when you are unsure about what to do, you might give up printing all together. Once you know everything that can go wrong in a print, with a little bit of time you can get back to 3D printing.

Verl Humpherys

I have been 3D printing since 2017, using both FDM and SLA printers. My prints have varied from small D&D figurines to full sized baby Groot. I printed mounts for my various game consoles and my Oculus Rift. Any problem you can have with a 3D printer, I have had. And I am here to tell you what I have learned.

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