3D prints keep suffering from warping

Question

I have a Prusa i3 made by Geeetech. My 3D prints keep suffering from warping when printing with PLA.

Whenever I print something with a base at about 10 cm x 10 cm, at least one corner of the print would warp up. I've read numerous articles about warping and tried all sorts of methods. My printer's bed is level, and heated to 60°C. My bed is made from clean glass. I've tried all sorts of adhesives. I tried blue tape, and used hair spray.

The only way for me to combat this is gluing the base to blue tape with 502 Glue. I used brim and the whole brim just warps up. I sometimes leave the model printing over night. For the first few hours it's perfectly flat. When I go back to it the next morning I'd find one corner warped up. This is very dysfunctional to my prints.

Is there a reliable way to stop this warping from happening?

Answer 1

For ABS it will warp unless you build a heat chamber.

That said the tricks to reduce warping come down to:

1. Material, i.e. PLA is less likely to warp;
2. Use a fan, it helps so much;
3. Make sure you have temps calibrated well - Too hot is more warp;
4. Use a raft. The Makerbot uses a raft and no heated bed;
5. Make sure the room is not drafty. Having it by the window will result in warping;
6. Adding a large brim also helps;
7. I find good ol' glue sticks work the best at keeping the print to the bed;
8. SMASH the first layer. This one is controversial. I personally do first layer at 130% and print speed of 30%. You get elephants foot sure, but it's on the bed real good.

Tom is right. It is very very hard to print that big of a piece without warping. That said I have done very large pieces on my Ultimaker, using a fan, glue stick, MatterHackers PRO PLA and no raft. But again that's on an Ultimaker.

Note you can build a heat chamber pretty easily. Specifically a passive heat chamber.

Answer 2

For PLA, I use a brim. The other thing that makes a big difference is obsessive care in levelling the bed and setting the Z-origin. Ideally, the first layer extruded (including the brim), should be almost "squished" onto the bed rather than being laid down at a height that allows a near-circular cross-section.
If the extruder head is too low, almost no filament will come out. If it's too high, there'll be very little adhesion. FWIW, I think a heated bed helps here, as it slows the cooling of this first layer and improves the adhesion as the fluid-phase 'grabs' the surface.

Answer 3

It might be useful you confirm again the bed levelling. I had warp on big pieces despite I thought my bed was properly leveled but in fact, for some reasons, the bed was too far from the head on one corner. If you face the same issue, you should see the bottom part of your print is showing the filaments not well melted to each others on the 1st layer. I really make sure the nozzle is gripping my paper sheet (almost scratching it when I move the paper).

Answer 4

Source (at least in part):

• SolidWorks 2015 Tutorial with Video Instruction, page 11-6, and;
• 12 ways to fight warping and curling, June 23, 2011 by MakerBlock

Curling

As printed plastic parts cool the different areas of the object can cool at different rates. 1 Depending upon the parts being printed, this effect can lead to warping and curling. Although PLA has a much lower shrinkage factor than ABS, both can warp and curl, potentially ruining a print. There are some very common ways to deal with this potential problem, the most notable being a heated build platform. However, sometimes that might not be enough.

1. Use a heated build platform. A heated build platform helps keep the lowest levels of a print warm as the higher layers are printed. This allows the overall print to cool more evenly. A heated build platform, sometimes abbreviated as HBP, helps tremendously with just about any ABS print and large PLA prints.

2. Print with a raft. Rafts are a printing option in ReplicatorG and Skeinforge. They’re basically a large flat lattice work of printed material underneath the lower-most layer of your printed object. They’ll also help reduce warping and curling by allowing your printed object to adhere better to your flat build surface. Other variations on this are to print with a larger raft and/or a thicker raft comprised of more layers.

3. Calibrate your starting Z height. A good first layer makes all the difference. If your starting Z axis height is too high, the extruded filament won’t be able to make a good bond with the platform. If you think your Z axis starting height is too high, try lowering it by 0.05mm increments until you find a good first layer.

4. Get the right build surface. Some people have experimented with different surfaces such as steel, titanium, glass, different kinds of plastic, different kinds of tape, and foam board. However, I find both ABS and PLA seem to stick really well to hot or warm Kapton tape.

5. Clean your build surface. ABS and PLA stick better to a clean build surface. Keep it clean of dust, pieces of old prints, and any other debris.

6. Print slower. Printing slower allows finer detail, better adhesion to the build surface and lower layers, and gives the printed part more time to cool evenly.

7. Print cooler. Printing at a lower temperature isn’t always an option. Ideally, you should be printing at the lowest temperature required for extrusion and that allows good interlayer adhesion. However, trying lower temperatures isn’t for the faint of heart. Printing at a too low a temperature could cause harm to your extruder motor or extruder.

8. Eliminate drafts or enclose your robot. Forrest Higgs found that having his 3D printer too close to an open window caused very uneven heating across his build surface. This in turn caused the side of his prints closest to the window to curl. Since keeping the window closed wasn’t an option for him, he compensated for the window drafts by adding a heat lamp. Cupcake and Thing-O-Matic owners might have an easier time of eliminating drafts by simply enclosing two or three of the sides of their robots. It will also have a fortunate side effect of helping to control fumes.

9. Design with mouse ears. Zach Smith’s solution was to add little discs to corners of an object to help those corners stick to the platform. These essentially serve as “mini-rafts” to give those corners more surface area and better adhesion without having to print an entire raft.

10. Design with aprons to hold down corners. Forrest Higgs suggested adding “aprons” around an object to be printed, while that object was being printed on a raft. These low thick pieces of plastic help keep the raft flat and help prevent any curling or warping from affecting the desired printed object itself.

11. Design with surrounding thermal walls. While Forrest Higgs’ apron approach provides a mechanical advantage of essentially holding down corners with a chunk of plastic, Nophead has added thin surrounding walls to his designs to act as baffles to keep warm air around the printed object as it moves around. He’s postulated that a very thin surrounding wall could have the same beneficial effect as printing inside an enclosed build chamber. Interestingly, it seems that Nophead suggests that designing objects with more rounded corners might also help avoid curling and warping at those corners.

12. Reduce infill. When printing a model you can chose to print it hollow, completely solid, or some percentage between zero and 100. However, as Nophead points out even the plastic inside a model exerts a force on the entire printed object as it cools. It stands to reason that the more plastic you have, the more those pieces of plastic will pull against themselves and the build surface as they cool. By reducing infill there will a reduced amount of internal tension as the object cools. Reducing these internal forces by printing with a lower infill ratio can help reduce curling and warping as well.