Platform won't stop at resin vat

[dongulim@gmail.com]

I've leveled many times and when I start a print the platform wants to continue down into the resin. It makes a very loud noise and won't stop until I shut it off. Any ideas? Support told me to put a spacer but now my printer will lift off the resin vat 20mm above it.

[cliffyk]

Remove the vat and entire platen bracket, then press the "Home" button :



Does the trolley stop before reaching it's mechanical limt?

If not then the optical limit switch is bad...

What alignment (aka "leveling") procedure are you using?

[Kasimira]

It sounds like the leveling is either not good or something it stopping it from reaching level point. Cliff knows more than I do but I experienced this my second time printing. I did not empty and clean the vat out and refill, I tried to just reprint because prior print did not make anything. It started doing what you are describing and upon emptying the vat to try to re-level I noticed maybe a 5 layer piece of resin stuck to the film. Must have been the failed print from before. Just that paper thin piece made the machine not be able to reach 0 to start print.

When you level make sure you are just using a standard piece of copy paper between the lcd screen and build plate. Then tighten all screws with all 4 corners touching firmly.

[cliffyk]

i have recently found¹ that using a piece of standard 20# copy paper folded in half (i.e. two thicknesses of paper, 0.18 mm in total) seems to work best. The OEM FEP is 0.15 mm thick si using a double thick layer of paper when performing the alignment provides a 0.03 mm (30 micron). "buffer" zone--and in theory an 80 micron bottom layer--seems to work best for me, seems top minimise the "elephant foot" phenomenon as well.

Using just a single layer of paper (0.09 mm) as a gauge sets the platen 0.04 mm (40 microns) too low and "into" the FEP.

I wish Elegoo specified a better gauge thickness for rhe alignment proces. "Sheet of paper" is not a standard unit of measure nor a worldwide standard unit of anything--but as the FEP is what normally lives b'twixt the platen and the LCD using a gauge of that thickness (0.15 mm) or a bit better seems much more sensible....

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¹ - I found this on my first print after installing the Jackson Products Twin-Rail Z-Axis. When printing the first layer the printer let out a squawk when it moved to the "0" position. I speculate that the dramatically increased rigidity of the Jackson mast was not as tolerant of the 40 micron "compression" mis-alignment caused by using just one thickness of paper as a gauge as was the OEM assembly, causing the stepper motor to complain. Using the double thickness of paper as a gauge fixed it all up. BTW the quality of my printouts has improved tremendously since installing the new mast--a night and day difference...

[carlson793]

Another possibility is the FEP has either debris stuck to it from previous print jobs, or has divots/peaks where items pulled on it while stuck to the FEP. I've had issues with both.

Debris can be removed after draining the tank. Make sure the FEP/tank is resting on a firm surface with maybe a paper towel under it, then carefully use the plastic putty knife that comes with your printer to scrape the debris off. Make sure not to press too hard, or you can can divots in the FEP.

Divots/peaks can sometimes be repaired with a hand-held hair dryer and a firm, flat, smooth item. Heat the FEP, set it on a solid surface with a paper towel underneath, then use the flat item to carefully rub the divot/peak out of the surface. Repeat a few times to get the divot/peak as flat as possible. It's not 100%, but it's the choice between doing something to possibly keep using the FEP, or just chucking it and buying a new set.