How to Choose Build Plate for Your 3D Printer
3D printer build plate, also known as print bed surface, is one of the basic components on a 3D printer that adheres and supports the bottom layer of printed objects. A better build plate provides stable and solid support, flat and smooth surface, and meanwhile better adhesion for the bottom layer of your print. It's the very first step that a better printed object begins to happen on your 3D printer.
Nowadays, there are a lot of different types of build plates on the market, for example, a glass or tempered glass plate, a polypropylene plate, a smooth or textured PEI sheet, or a PEX build plate. How can we choose an appropriate build plate for our 3D printer?
Basics about 3D Printer Build Plates
To begin with the above question, let's learn some basics about a 3D printer build plate.
Usually, a build plate can be made of a piece of glass or plastic, or a piece of spring steel coated with special material for melted filament to deposit and adhere.
Thus, the mechanic features and the surfaces decides the performance of a certain kind of build plate or a specific build plate. For example, a glass build plate prints object with ultra smooth bottom layer but needs glue while printing; a PEI sheet adheres filament better, and needs no glues any more.
Popular Types of Build Plates on the Market
As mentioned above, regularly we often see glass or tempered glass, polypropylene, smooth or textured PEI and PEX type build plate for a FDM 3D printer on the market. Let's proceed to know them one by one.
Glass & Tempered Glass Build Plate
Glass build plate is the most commonly seen build plate on the market, especially on budget 3D printers for its lower cost but great compatibility with PLA printing. For example, the oringinal Creality CR-10S build plate is a glass sheet. The Ultimaker S3 and S5 3D printers are also typical examples of glass build plates.
Pros & cons of glass build plate:
Pros: cheap, great for PLA, smooth bottom layer, easy removal of printed object and cleanup after printing;
Cons: often needs to apply glue or tapes on to enhance bottom layer adhesion
Tempered glass build plate is stronger and more durable than common glass bed. Being pre-stressed or tempered, this kind of build plate has stronger structure and can withstand impact shocks far better than regular glass.
Meanwhile, with special coated surface, tempered glass build plate offers more adhesion to melted filament.
We can see tempered glass build plates on either a Kingroon KP5L or a Creality Ender 3 3D printer.
Polypropylene (PC) Build Plate
A polypropylene build plate is of course made of polypropylene, a kind of thermoplastic that makes the plate partially bendable, and we often call it PC build plate for short.
As a plastic sheet, PC build plate adheres filaments (which is also made of plastic) better than any other types of build sheet. This feature makes a PC build plate also a good surface for beginners in 3D printing.
Pros & cons of polypropylene build plate:
Pros: the easiest surface to start with; good adhesion which makes up for bad leveling or gap setting; best for PLA or TPU printing
Cons: lower melt temperature, not suitable for high temp printing filaments
Smooth & Textured PEI Sheet
A PEI sheet for 3D printing is often made of spring steel and coated with polyetherimide (PEI for short) powder on its surface, either smooth or textured.
PEI sheet has strong adhesion properties and chemical stability that makes it a good option for FDM 3D printing. Prusa 3D printers are big fans of spring steel PEI sheets.
Smooth PEI sheet offers glossy bottom finish for your print while textured PEI sheet provides relatively more adhesion and a textured bottom finish.
In addition, a double sided PEI sheet can be smooth on one surface and textured on the other surface.
Pros & Cons of PEI sheet:
Pros: high temp stability and wear resistant; highly adhesive and no need of glues or tapes; compatible with nearly all types of filament; can be used on either a heated or a unheated print bed
Cons: soft coated surface can be damaged by excessive scratching; sometimes adheres too strong to the printed object
PEX Build Plate
PEX build plate is similar, yet superior to PEI sheet because of its much thicker coating and higher temp resistance.
A PEX build plate has a higher glass transition rate and higher melt point than PEI sheet, which allows it to print high temp filament like PETG without worrying about the surface bonding with deposited filament.
Pros & Cons of PEX build plate:
Pros: higher strength and temperature resistant; can print higher temp filament like PETG
Cons: a little lower adhesion on the surface, need better leveling and appropriate gap settings; sometimes needs high temp adhesives to guarantee the result.
Other popular names for build plates
You may also hear other popular names of a build plate, such as flexible build plate, magnetic build plate. These names usually describes other features of a build plate rather than material related performances.
A flexible build plate means it can be bent for much easier printed item removal. Usually, a spring steel PEI or PEX build plate is a flexible build plate; and a PC build plate, which can be partially bent, to some extent, is also a flexible build plate.
A magnetic build plate is developed with magnetic characteristics to adhere to the print bed. Usually, a magnetic build plate is flexible.
For example, some popular 3D printers like Kingroon KP3S, Creality Cr-10 and Cr-10s are using magnetic removable build plates.
Guidance for printing on different build plates
Undoubtedly, different build plates have different mechanical properties, heat conductivities, adhesion properties, and etc. And below tips might help you with a good start.
Guidance for your reference:
Glass build plate
Recommended material: PLA, ABS, PETG, TPU, nylon
PLA, bed temp 60℃; moderate gap
PC build surface
Temperature tolerance: about 120℃
Recommended material: PLA, ABS, PETG, PC, TPU, nylon, polypropylene
PLA, bed temp 40-60℃; moderate or a little higher gap;
PEI build plate
Recommended material: PLA, ABS, PETG, TPU, nylon
PLA, bed temp 70℃; small gap
PETG, bed temp 70℃; moderate gap
PEX building surface
Recommended material: PLA, ABS, PETG, TPU, nylon
PLA, bed temp 70℃; gap as tight as possible for full filament flow
PETG, bed temp 70℃; moderate gap; hot end 240-250℃ to avoid fusing with surface
Note: above guidance is for reference only; settings may change according to different material qualities, printers, conditions, and etc.
How to Get Better Build Plate Adhesion
When 3D printer filament won't stick to bed or stick poorly, it can be caused by dirty build plate, not well leveled hotbed, inappropriate Z offset, inherent cons of materials or build plates, or sometimes the special structure of the object you're going to print.
1 - Clean the build plate
Hence when poor build plate adhesion happens, check if the build plate has filament residues or excessive glues on its surface. If so, do clean the build plate first. For stiff surface like a glass bed, you can use a spatula (usually come with the printer) to shovel filament residues off and wipe the surface clean with a soft cloth; for too sticky residues or on soft surfaces like PEI sheets, you can apply some isoproply alcohol on and soak the residues soft to remove them.
2 - Re-level the printer bed
Incorrect bed leveling is another common cause of poor build plate adhesion. You can do bed leveling test printing first and then decide whether to re-leveling your printer bed.
Bed leveling test print: https://www.thingiverse.com/thing:2187071
For how to level your 3D printer bed, you can visit: https://all3dp.com/2/3d-printer-bed-leveling-step-by-step-tutorial/
3 - Adjust Z-offset value
Z-offset value is a crucial factor in FDM 3D printing. It depicts the distance from the nozzle to the home position of the Z-axis. If Z-offset value is wrong, the nozzle can be too far or close to the build plate, hence poor bed adhesion happens.
To find correct Z-offset for your 3D printer needs repeatedly try higher or lower values and consumes a lot of effort. But it's worthy for excellent outcome of your prints.
4 - Use solid glues or tapes
For a smooth surface like a glass bed, the inherent nature provides it a relatively poor adhesion. At this circumstance, some solid glue or tape onto the build plate can be a good solution.
5 - Set brim or raft while slicing
Some objects have low adhesion to the build plate because of their bottom layer have less contact with the bed. And slicer default setting can be skirt, but skirt doesn't help in bed adhesion. For these objects, we can alter to brim or raft to assist with better bed adhesion.
6 - Adjust bed temperature
Incorrect bed temperature affects bottom layer adhesion too. Too high bed temperature leads to sticky bottom layer to the surface while too low bed temperature results in warping. You can do test print and try rise bed temperature by 5 degrees Celsius per time until you find the most appropriate bed temp for your print.
7 - Alter first layer printing speed
The first (initial) layer printing speed affects bed adhesion too. Try alter the setting by slowly raise or drop the value when previous steps do not solve your problem.
8 - Replace the build plate
The last thing to improve build plate adhesion is when we find flaws (uneven surface, residues unable to remove or deep scratches) on the build plate itself, just replace the old one with a new build plate.
Some build plates just don't fit for some filament types, then you can replace it with a new build plate which fits the material better.