Elegoo Mars Prints Sticking To FEP: Here’s What To Do

Having prints sticking to FEP film instead of the build plate is a common problem. In fact, if you have an Elegoo Mars or any other 3D printer, it’s unlikely you’ll never experience this problem. 

Fixing your Elegoo Mars prints sticking to the FEP can mean troubleshooting. For example, you might have to lower the heat of the bed. You might also have to level the bed, increase the bottom layers, or adjust your resin settings in some other way. 

7 Reasons Why Elegoo Mars 3D Prints Stick To FEP

If your prints are sticking to the FEP or resin tank instead of the build plate, it’s probably a fixable issue.

In fact, most sticking issues relate to one of the following 7 reasons. 

1. Build Plate Isn’t Level 

If the build plate isn’t level, it could cause uneven adhesion to the build plate. That could cause instability in the print model. This means it may stick to one side of the FEP and not to the build plate. 

Your build plate may not be level for several reasons.

For example, if you tried to level it with resin in the tank. Alternatively, you may not have properly loosened the screws.

Finally, you may not have tightened one of the screws enough after leveling the platform. 

How To Fix 

Leveling your build plate is normally a relatively quick process. Make sure your resin reservoir is empty before getting started. 

1. Fasten the rotary knob.
2. Loosen the screws.
3. Place a piece of paper on the build plate.
4. From the menu, press “Tool” –> “Manual” –> “Home”.
5. The Z-axis will go down and then stop.
6. Adjust the platform to keep it in the center position.
7. Tighten two of the screws, starting with the #1 on the front, then the #2 on the left. If your model has a #3 screw on the opposite side, tighten it as well.
8. Tug the paper, if it pulls out easily, you’ll want to lower the Z-axis. If it pulls out with only slight resistance, leveling is complete, if it has too much resistance and doesn’t move, you’ll want to slightly raise the z-axis. You can do so from the menu. Use the menu to raise or lower the Z-axis by 0.1mm and then check again. 
9. After leveling is complete, set the Z-axis height as the height of the current first-level position based on those adjustments. 

2. Base Layers Are Too Thin 

If the base layers are too thin, don’t have time to cure properly, or don’t provide enough support for the print, your print will stick to the base plate. 

How To Fix

Set your Bottom Layer Count to a minimum of 5.

You can choose to have more layers. However, you probably don’t need them.

In most cases, you want about 5 layers no matter which type of resin you’re using. Some users 

3. Bottom Exposure Too Long 

If the build plate is too warm, it can slow cooling for too long.

Then, when the print gets too heavy, the still-soft bottom layers will start to deform. This can cause them to stick to the FEP. 

How To Fix

Check the bottom exposure for your resin type and update it accordingly.

Elegoo maintains a Google Drive document with optimal settings per resin type – per Elegoo printer. These settings will be slightly different depending on whether you have a Mars, a Pro, etc. 

However, in most cases, you can expect bottom exposure time to hover between 50-70 seconds for the Mars, and 45-60 seconds for the Pro.

That also depends on which color of resin you’re using. For example, if you have the Mars, Elegoo recommends 90 seconds for Maroon and Black resin, 70-75 seconds for translucent, and 60-70 seconds for everything else. 

4. Build Plate Is Greasy Or Dirty 

If your build plate is dirty or greasy, the resin won’t stick. That holds true whether you have a layer of dust, fingerprints, or oil of any other kind.

Even part of the build plate being dirty can cause a partial no-stick issue, resulting in the print sticking to the FEP. 

How To Fix

Thoroughly clean your build plate.

Normally, using an alcohol wipe should do the job to remove any residue or oil. Then, when you remove prints from the bed, use rubber gloves to prevent getting oil from your hands on the bed. 

5. Model Is Too Large 

If the model is too large, it might mess up the seal on the bottom.

Here, an increased amount of bottom surface area increases the amount of suction on the FEP. In this case, the FEP may touch the mesh, the plate may flex too much when you’re pulling the model off, or you might experience other similar issues.

Whatever is causing it, the issue often results in the print sticking to the FEP layer. 

How To Fix

There are several ways you can go about fixing this.

One is to design the model with supports or a lattice base to reduce the amount of surface pressure. This will require more work as you’ll have to remove the supports or base after the print is finished.

Here, you’ll want to design a 45-degree tilt into the model to reduce the amount of suction pressure. 

However, many people also have luck with taping around the edge of the LCD before leveling the bed. You then put the vat back on over that.

This creates just enough lift on each side to slightly raise the mesh off the FEP layer. That can be enough to prevent a large model from suctioning to it too badly. 

6. 3D Model Design 

Most 3D print design programs will tell you if your model fully connects to the bottom of the build plate. If your model does not, you will likely have issues with it sticking. 

If you’re unsure, try printing something that you know works. Or, have someone look at your model.

Many premium slicers, like ChiTuBox will also show which parts of the model connect to the build plate and which do not. 

How To Fix

Make sure your 3D design fully connects to the build plate. 

7. Other Sticking Issues 

In some cases, you won’t be able to figure out why your print is sticking to the FEP and not the build plate.

You should always try to troubleshoot the above options before looking for a temporary solution. 

How To Fix

Use silicone spray or teflon spray. You can also try putting Talcum powder on the screen. However, you shouldn’t have to do this.

If you can’t fix the problem through any of the other methods here, you may want to contact Elegoo for help. 

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How To Remove Failed Elegoo Mars Prints From FEP

It’s important to wear protective equipment and to ensure you’re working in a well-ventilated room. 

1. Unscrew the two thumbscrews on either side of the vat.
2. Check that there is no liquid on either side of the vat, if so, wipe it off with a paper towel.
3. Carefully slide the vat towards you, being careful not to tip the liquids.
4. Return the liquid resin to the storage container by carefully pouring it into a funnel. Clean up any resin you spill.
5. Cover the failed prints in the vat with 90% isopropyl alcohol.
6. Make sure you’re wearing rubber gloves. Then, gently use your hands to massage the prints up from the bottom. Don’t use a sharp object and don’t push too hard, as you will damage the FEP film. 
7. Clean the vat using more isopropyl alcohol. 

Here, you’ll also want to inspect for any damage to ensure that the FEP film is still in good condition. 

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How To Change Your Damaged FEP Film

If the FEP film on your resin vat is damaged, it may be a good idea to replace it. Here, you’ll need a new sheet of film and basic tools. 

• Start with an empty resin vat.
• Remove the screws around the outer edge of the vat. The Mars has 10 of them.
• Push the FEP film bracket out of the vat.
• Remove the inside screws. The Mars has 26 of them.
• Take the bracket apart.
• Remove the old FEP film.
• Place a sponge or other thin, protective material in the middle of the bottom bracket.
• Peel the protective layer off the new FEP sheet and put it in place with the sponge to keep the film from touching the table.
• Replace the top bracket.
• Put the screws back into place.
• Put the bottom frame back on and re-install the screws around the outer edge.
• Cut the film to size.

From there, you can reinstall the resin vat and use it as normal. 

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Wrapping Up

If your Elegoo Mars is having issues with the print sticking to the FEP, you’re not alone. Unfortunately, it could be because of a number of issues. However, you can likely quickly troubleshoot the issue.

Here, it’s always a good idea to check if the bed is level, check the print settings versus resin type, and make sure you’re using enough bottom layers. 

In the worst case scenario, you can always use tape, silicone spray, or talcum powder, but you shouldn’t have to.