SL1s, nothing is sticking
Hi, I hope someone can help, I upgraded to the SL1s, since doing so I have never had a 100 percent perfect print, where as before when it was the SL1, I rarley had a failed print, so the problem is, I can not get the print to stick to the print bed, sometmes a part of the print works and when it does its great, but 9 times out of 10 nothing sticks. I have cleaned with IPA 99.9, washed with dish soap and hot water, I even tried cleaning with Acetone, I also used a scotchbrite scourer, I have 2 vats, both with new FEPs, I am now at a loss as to what I can do, I thought about using the old build plate, as I know they work. anybody any ideas please. Ted
Is there any pattern as to when they stick or not? For example the rear of the plate vs the front, left vs right, different settings, etc...
When the prints do stick, how do they look close to the platform (e.g. the pad if you are printing on supports)? Any unexpected angularity?
Sounds like you've attacked the cleaning of the plate well. Have you gone through the wizard again to recalibrate? Could be that the platform isn't as far down as it should be. Have you tried raising your initial layer time? Too low of a value can cause adhesion issues. I know there are tilt speed options on the S (still on the plain SL1 myself), try adjusting that to see if it helps.
Initially I had a lot of trouble with my SL1 not sticking (and what did had skewed pads) and ended up using a level to level my platform and adjust the LCD tilt. After that it worked great until I replaced my LCD (died at 161 hours due to some internal failure) after which trusting the calibration wizard worked and it went back to flawless printing. Prusa wanted the dead display back to warranty it and they never told me if they found anything, but I suspect there was an assembly issue that was causing my leveling issues and ultimately led to the failure. Since I never noticed anything by examining the LCD assembly I can't tell you want to look for, but if the usually adhesion "fixes" don't help, you might pull your LCD and give it a good look over to see if anything stands out or doesn't feel right.
Not sticking
Hi, yes, they stick slightly back in the middle of the plate, I have re-calibrated 3 times, thinking, maybe I hadn't adjusted the tilt enough, I've also used 3 different resins, 2 Prusa own brand and an Elegoo, which worked fine before the upgrade
Hi, yes, they stick slightly back in the middle of the plate, I have re-calibrated 3 times, thinking, maybe I hadn't adjusted the tilt enough
That definitely sounds like a potential leveling issue and very similar to what I saw with my SL1. One downside I now see of the new platform is that with it's slopped top, putting a small level on it is more difficult...
If you have a small enough level you could try using that rather than the tank (at least I'm assuming they haven't changed that process) to set the home position of the LCD. You might also try (carefully) removing the LCD and make sure there is no debris or anything preventing it from sitting all the way down in it's holder.
I've had problems for a long time, both with SL1 and after I upgraded it to SL1S. But now I have solved them.
For a long time, I had problems getting the initial layer to stick to the platform instead of the FEP. Printing at 50 µm was hit and miss, and trying 25 µm never worked. I then came up with a workaround pre-curing a thin layer of resin on the platform before printing. I wrote about it here: https://forum.prusa3d.com/forum/postid/181036/
I used that method until my SL1S upgrade. In hindsight I DON'T recommend using it, unless as a last, desperate attempt. It works fine, but it leaves hardened resin on the build platform, and it is a royal pain to get off.
Then I upgraded to SL1S, and with a fresh platform surface I thought that now my problems would be over..... NOPE. Same problem. No amount of changing the initial layer time helped.
Finally I tried to re-run the calibration, but this time when the platform gets seated in the vat and tightened down, I only held VERY LIGHTLY on the top knob with a single finger. Just enough to keep the platform in place when tightening the bolt. On previous calibrations I've used more force, but this time almost nothing. After that I can now print both 25 and 50 µm reliably, using default slicer settings for initial layer time.
I then came up with a workaround pre-curing a thin layer of resin on the platform before printing.
I've seen that recommendation before. Another I have seen given for non-Prusa printers is passing over the platform with a super fine grit sand paper (1000 or higher) to rough up the surface just a bit. As manually leveling fixed my issues I never ended up trying either of those ideas though.
not sticking
yes I have a small level, I will try that, trying another print on it at the moment, hoping it works.
fine resin layer
I saw that as well, but I wondered, when you remove the print, it would also remove a part of the layer, so you would need to remove that as well then re do it every print.
stillnot sticking to print bed
well i tried a spirit level, was very slightly out, so leveled it off in calibraion, but still nothing sticking, I just used wat and dry 1500 grit on my other plate, so will see if that works
but I wondered, when you remove the print, it would also remove a part of the layer, so you would need to remove that as well then re do it every print.
Correct. It comes off the plate where a print sticks to it, but on the part of the plate that isn't printed on, the thin layer remains. This eventually leads to an uneven plate, and then it is time to remove it all and start over. Note: It doesn't come off willingly.
Luckily I don't have to use that method anymore, as a recalibration (with only a light touch at the right time) fixed everything for me, as described above.
RE: SL1s, nothing is sticking
I had a similar problem with my SL1 and resolved it by first physically making the machine level. I used a spirit level to check its level, then adjusted the base to physically insure it was level. Then I ran the calibration process and resolved the issue for future prints. One thing in the calibration process, on the step where you've set the empty resin tank at a 90 degree angle across the printer frame (LCD Printing Display) and you're adjusting the frame to be in direct contact with the resin tank (see step 3 here - prusa3d_manual_sl1s_en.pdf), I actually had better results by adjusting it up one more time after initial contact.
Those two adjustments to my machine resulted in an elimination of failures for me. Good luck!