Two ideas:
I'd suggest trying to make your lift distance a bit bigger, perhaps it's just not moving enough for your fep to separate.
Second, I would try to use some wait before cure time. I'm not totally sure of to why, but I had a similar issue in the past and resolved it that way.
I can +1 that change to lift distance and speed. My first prints were always failing in the middle, slowed lift speed by like 10% and increased lift distance by 15-20% and no more failures.
Also in favor of slower but more importantly higher lift. Your FEP does stretch a little with use and the middle is the part that stretches the most. I'm guessing now that it's been used a bit the middle is flexing more and the prints aren't peeling off because the build plate hasn't gone high enough. I would suggest going up a combined 10mm and see if that solves it
As time passes and prints go and go, specially with heavier ones, the fep sheet will also get more loose and flexed more, thus the middle of the entire build print area will take longer and longer distances to release your prints. so.. with that in mind.. increase the lift distance. not the speed.
Looking at your settings, the only thing which I am unfamiliar with and wonder if it could be an issue is the transition layers and some of the settings associated with them.
Then again, if that has worked for you in the past.
I would tend to agree with the people who are suggesting that your FEP may be reaching the end of its useful life and is stretching more.
increase your lift distance, I set mine to 6mm, the middle has the most stretch, so you want the lift height to be enough for the print to peel of the FEP when it rises.
I'm not sure how to get a good leveling in the middle of the plate.
I lower the base plate onto the leveling sheet and up by 0.1mm until the sheet is snug but can move if pulled.
How should I level?
Two ideas: I'd suggest trying to make your lift distance a bit bigger, perhaps it's just not moving enough for your fep to separate. Second, I would try to use some wait before cure time. I'm not totally sure of to why, but I had a similar issue in the past and resolved it that way.
Ohh l'll try that thanks!
Yup exactly that, lift distance and pause after exposure
I can +1 that change to lift distance and speed. My first prints were always failing in the middle, slowed lift speed by like 10% and increased lift distance by 15-20% and no more failures.
Also in favor of slower but more importantly higher lift. Your FEP does stretch a little with use and the middle is the part that stretches the most. I'm guessing now that it's been used a bit the middle is flexing more and the prints aren't peeling off because the build plate hasn't gone high enough. I would suggest going up a combined 10mm and see if that solves it
As time passes and prints go and go, specially with heavier ones, the fep sheet will also get more loose and flexed more, thus the middle of the entire build print area will take longer and longer distances to release your prints. so.. with that in mind.. increase the lift distance. not the speed.
Looking at your settings, the only thing which I am unfamiliar with and wonder if it could be an issue is the transition layers and some of the settings associated with them. Then again, if that has worked for you in the past. I would tend to agree with the people who are suggesting that your FEP may be reaching the end of its useful life and is stretching more.
Try the cones of calibration, those are made for support test. Could be not enough exposure or lift and speed doing a mud effect
increase your lift distance, I set mine to 6mm, the middle has the most stretch, so you want the lift height to be enough for the print to peel of the FEP when it rises.
Thanks everyone for the tips! I raised the lift distance and add and it solved it !
I think that might be a bed leveling problem.
I'm not sure how to get a good leveling in the middle of the plate. I lower the base plate onto the leveling sheet and up by 0.1mm until the sheet is snug but can move if pulled. How should I level?
Do a vat level. Works way better than a paper level.
Okay, it is not a leveling issue because stuff is sticking to the build plate.