11-25-2019, 03:46 AM
I had the problem that the very first print (test tower and some custom test objects) came out perfect but then the next about 10 prints failed. I then had one print in between succeed only to have them fail again, this time only on the left side of the build plate (this means: objects right side came out perfect but objects on the left stuck to the FEP).
Now my last five or six prints succeeded, so it seems I found the recipe to success at least for my machine. I'm using Elegoo black and white resins.
I slightly sanded the build plate with a coarse sandpaper to make it a bit less smooth. For this, I placed the sandpaper flat on a table and then placed the build plate onto the sandpaper with some circular motions. This way I can also be sure that the build plate is really flush/flat. I also added a bit of masking tape to the sides of the UV LCD, like many are doing. Don't know if that makes any difference, though; it's supposed to help prevent a vacuum between the FEP and the LCD.
I'm now doing this before every print (might be overkill; don't know yet):
Between the all-prints-fail and all-prints-succeed periods I did experiment with the light settings but actually ended up with the values I was using from the very beginning: 50s for the first layers, 6 layers, 7s per normal layer. So I can least say the these are not factor in my case.
Now my last five or six prints succeeded, so it seems I found the recipe to success at least for my machine. I'm using Elegoo black and white resins.
I slightly sanded the build plate with a coarse sandpaper to make it a bit less smooth. For this, I placed the sandpaper flat on a table and then placed the build plate onto the sandpaper with some circular motions. This way I can also be sure that the build plate is really flush/flat. I also added a bit of masking tape to the sides of the UV LCD, like many are doing. Don't know if that makes any difference, though; it's supposed to help prevent a vacuum between the FEP and the LCD.
I'm now doing this before every print (might be overkill; don't know yet):
- I zero level the build plate. I did this one wrong before! After removing the vat, I place a piece of paper on the Mars, loosen the two screws of the build plate, then press the button to lower build platform. After it has reached the bottom I tighten the screws while holding the build plate down. I've seen a video where it was explained that you should then switch to the 0.01mm setting and increase the height until you can pull out the paper while still getting some resistance. For me, that's raising the build plate by 0.02mm. Then I tap the Z=0 button. I missed this last step before! Ever since I do that my prints succeed.
- I also apply some teflon lube to the FEP. I spray it onto a soft paper towel and apply it to the FEP until no droplets can be seen. This is meant to help preventing the resin from sticking to the FEP. How much that is helping I don't know, I still get to hear the typical "clicking" sounds of the resin coming lose of the FEP when the build plate is raising after each layer.
Between the all-prints-fail and all-prints-succeed periods I did experiment with the light settings but actually ended up with the values I was using from the very beginning: 50s for the first layers, 6 layers, 7s per normal layer. So I can least say the these are not factor in my case.