While not being able to get your print to stick to the build plate is a common issue, not being able to get it unstuck again afterwards is another unfortunately common issue. These two issues tend to go somewhat hand-in-hand, in that often after you solve an inability to stick you create the inability to unstick. The solution to both of these issues is to find a healthy balance, but that can be difficult.
Tips for freeing prints
If one of your prints is currently stuck, leaving it to cool down is probably your best option. When filaments are hot they are sticky, this helps them bond to other layers and stick to the print bed. As they cool this stickiness reduces, combined with thermal shrinkage, sometimes prints can just pop right off. It’s especially important to give a print time to cool if you’ve got a heated print bed. This heat would have been keeping the bottom of the print warm and sticky.
If the print still doesn’t come off easily, the next thing to try is a palette knife or another similar thin prying tool that you can try to carefully use to pry the print free. Just be careful not to damage the print and ruin your hard work.
If the print doesn’t come off with careful prying, you might want to try cooling the print bed. This takes advantage of the differing rates of thermal contraction of the two materials. Try carefully running cold water over the print bed, avoiding soaking the print. You generally don’t need to panic about a little bit of water getting on it though. You can even try putting the print bed on top of some ice packs to cool it further. Throughout this process, continue to carefully attempt to pry the print free. You should only ever do this if your print bed is removable. Water and even condensation from sub-ambient cooling will be bad for the rest of the electronics of your printer.
If you’re stuck on how to remove a stubborn print, you can try putting it in the oven. 100 degrees is generally a good starting point, but research the glass point of your filament and try to stay under that to start with. If absolutely nothing works you can also turn it up enough to properly melt the print, so you can just pour it off, just be sure not to let the plastic pour off the print bed and stick to your oven because that will be much worse to clean. Do not try this at all if the print bed isn’t heat resistant, if it has electronics attached, or if you don’t have some way to contain melted plastic in case you need to go that route or do so accidentally.
Tip: Ovens tend to overshoot their set temperatures when heating up. It’s best to preheat the oven and then put in your print.
Tips for future prints
While it won’t help to save your current print, it’s likely a good idea to give your print bed a clean. Dirt and residue from old prints make it easier for the print to stick. This is because they all add extra texture to the surface. You can scrape the residue off while cleaning it with hot water. You can even leave it to soak in hot water if needed. Once you’ve cleaned the print bed, check for pits, chips, and scratches. If there are more than a couple, try turning the print bed over to a new side. You may unfortunately also need to get a new one. Hot water can also help to remove prints in some scenarios.
This sort of problem is often associated with cheaper filaments. It’s generally worth paying for good-quality filaments as they can help prevent or reduce a range of issues.
If possible, you can try to design your models with holes on the base of your print in order to try to reduce the sticky contact area with the print bed and to reduce the suction effect. This is only helpful if you plan in advance however and doesn’t work with many models.
These tips should help you to be able to remove a stuck print and to reduce the likelihood of future prints sticking. If you’ve got any other tips to help remove stuck prints, please share them down below.