When 3D printing, it is NOT going to be easy. It's not as simple as loading the 3D model, slicing the 3D model, and printing the sliced model. There are many things you have to look for before starting a 3D print, such as ambient and bed temperatures, or Z Calibration. Here are a list of the top <some amount here> problems!
- Heat bed is too cold: When the heat bed is cold (or at least not hot) 3D prints tend to warp. Warping occurs when the bottom of the print cools faster then the top, and expands. A hot heat bed keeps the print on it warm on the bottom, where it would typically get cold from the ambient temperature of the environment.
- Heat bed is not level: This is a rare problem, and shouldn't normally occur. However, sometimes you may notice that the nozzle is printing too high above the bed and at other places it is scraping the bed. This usually means that the bed is bent in such a way that on end of it is bent upwards while the other end is bent downwards.
- Ambient room temperature is low: When the room temperature is too low, it will cool the heat bed. Heat beds are usually very weak anyway, and won't stand up to a cold room.
- Not enough adhesion: When your prints are coming off of the bed during printing, it probably indicates that you do not have enough adhesion for the print to stick to the (heat) bed. When adding adhesion, you will need to use some sort of tape (so as not to dirty up the actual metal bed).
- Z Calibration is wrong: You will notice this when either the nozzle is scraping into the bed or it is too high above it and the plastic is not touching the bed enough. You have to calibrate it every few weeks, to get perfect prints. Usually, you have to get this correct within 0.05 of a millimeter.
- Bigger 3D Prints Are Warping: This is common, and mostly happens because the middle of the heat bed is where the heater is, and is a lot hotter then the outer edges of the heat bed. Also, it has a lot more space that can be hit by a cold draft.
- Under or Over Extrusion: You will notice this when the 3D prints have bits of plastic sticking up above the current print layer, or plastic wrapping around the nozzle. This means it is printing too much plastic at a time. For under extrusion, you will see very thin wallsthat aren't even very solid.