I have had my printer for over a month and have ran around 30 prints. In the beginning, that parts adhered to the build platform so well that they were difficult to remove. Now, I am slowly loosing adhesion. My first step was to “Fine Tune” and adjust the offset so the build plate went lower (0.2mm). This worked for another 5 or so prints. Now, I just had to adjust it further (0.6mm), and again it is working better. However, the trend is a bit discouraging.
Here are the symptoms:
Some parts fail to adhere at all. This results in a cured lump on the silicone that I must remove.
Some parts partially adhere. About half of the base will be solidly attached, but the other half will be loose and curl up off the plate. This sometimes results in distortion in the part being printed, but often, the print turns out just fine.
Some parts work out just fine, and they have solid supports.
If I print three parts at the same time, I have experienced instances where some will attach fine and others will not. As far as location on the build plate, I seem to get better adhesion on the side opposite to the “Hinge Side” listed in PreForm.
This shows the bottom of the base for the support structure. The bottom most part of the base is perfectly smooth and has a texture matching the build plate. This area was well adhered. The upper portion is gummy, glossy, and was loose from the build plate. The printed part was perfect, so I don’t believe any optical issues to be a factor:
Have a similar issue with my original build platform. It’s now sitting at the max 1mm lower. I got a new one and comparing the two is interesting. Without measuring it does appear that the old one has gotten ever so slightly thinner and it doesn’t slide and sit as tightly in position even with the screw tightened. I suspect it’s just a case of wear and tear and another part that over time will need replacement.
To be honest, I haven’t bothered switching over. Models still stick to the build platform so no issue there. Once I start having issues with the printing I’ll make the switch.
To help improve adhesion with the original I have scored it with a sharp modelling blade which seems to help.
Actually I just remembered something else, with regards to the original print shown, when was the last time you completely emptied the resin tank and left it exposed to the air for at least an hour? I found this issue was more likely to happen when I had left the resin in the tank for a while even if I scraped it for a few min before starting a print.
I never remove the resin unless I am thoroughly cleaning the tank which is rare. I would like some input on why exposing the silicone to air would make a difference. Have you found any resources?
Can any FormLabs people tell me why air exposure makes a difference to the silicone? Does it?
I assumed that because we can store the resin in the resin tank for the life of the resin, there was no reaction between the silicone and resin. How long should I leave the tank open to air?
I will give it a shot though, and I will see what happens. Thanks for the idea.
There were a bunch of threads a while back on the subject. Essentially the PDMS layer has to be exposed to air to keep working properly. In short succession between prints it’s fine to just expose it by scraping it with the scraper several times but if leaving it for long term I find it best to filter the resin back into the bottle and leaving it exposed with the lid on the tray.
I had adhesion problems too after a while. The platform surface was getting smooth. I just took some course grit sandpaper and lightly sanded the aluminum to restore the texture. It actually adhered way too good for a few prints, then worked great after that.
