Flat heated bed replacement for uneven bed
So the heated bed I got with my anet a8 is not entirely even. The middle of the bed is lower than the outer edges of the bed, which always causes issues with the first layer, especially with a larger print.
I know I could do mesh bed leveling but I don't want to have to do that every time before I print.
So my question is, where do I find a heated bed that I can be sure of will be even and not have dents anywhere?
If your bed is aluminium, it should be rather easy to reduce the dipping by bending the bed the other way around (after having removed it from the carriage). Try to apply pressure with the palms of your hands (as to spread the force on a larger surface) and use a ruler to verify the effect after every push. I did *not* manage to completely flatten my bed, but I manage to get rid of all adhesion issues at least.
Several things to consider:
- Nothing is perfectly flat. It is flat within a tolerance. The bed you have now is flat to within a tolerance. If you want a flatter bed, you are going to have to specify how flat.
- As @mac mentioned, aluminum is bendable; so, what once was flat can be made un-flat and the other way around. Note: Your problem may not be your bed, it may be that the bed mounting frame has introduced stress that is bending the bed.
- Because the heating element is applied to one side of the bed, the differential heating (between the top and the bottom) can cause the bed to bend at temperature; so, flatness could vary with temperature.
What to purchase:
- The Anet A8 has a 220x220 bed. A very popular size. You can get replacements heated beds for as little as $20 from a lot of sources.
- Because of the considerations above, rather than replacing the bed, you may want to consider attaching a 220mm x 220mm Borosilicate Glass Plate to the top of the bed. These are also readily available (even from Amazon) for less than $20. That is what I did. The glass makes for a very flat surface and a great printing surface. I attach mine with small binder clips. That makes it easy to remove to take the print off or to clean when needed.
How do you keep the glass from deforming if the high point of the Al bed is anywhere near the center? Put another way, have you ever seen the glass "hold off" from the metal bed at the binder clips, leaving a gap at the edges?