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Does anyone have any tips on how to avoid (minimise) the risk of warping through design rather than by technique (i.e. temperatures, tape, etc.). Are curved edges to flat bases worse than square? Thin or thick sides? Support structures as part of the design internally?

I hate warping, and while I can usually avoid it with the right machine/bed prep, it’d be nice to be able to predict and minimise the chance of warping with the customer model before it’s even sliced…

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When it comes to warping and not sticking to the bed I sometimes will build in a layer or two thick, circles at the corner edges of my item to help hold them down. Imagine something like a coin laying down at the edge/corner of the base of the print. I will make them so they are easy to cut away.

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Infill can cause warp. The plastic inside a model exerts a force on the entire printed object as it cools so the more plastic you have inside, 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. Experiment with the type of infill pattern: honeycomb, grid, rectangle, etc. On my printers I find that a honeycomb infill often leads 80% of the time to warp prints where as rectangular I don’t get warping.

Hollow out a design. Again related to infill and is beneficial for really large prints.

Wall thickness. Thicker doesn’t always mean better. Thicker walls require more infill which comes back around to the inside plastic exerting force on the overall print as it cools and causes the print to warp.

Divide the design up. This is good to reduce support structures as well as stress points in a design.

Filament can be a cause for warping. Just because it is brand new out of the package or cheap doesn’t mean it is a good filament. In the manufacturing center where the filament was made, debris and moisture contamination can still get into the filament which can affect how well the print sticks to the bed or the overall quality of the print. Store your filament in a container when not in use with moisture absorbing packets in a dark place away from light to have the filament last longer.

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Round objects warp less than square objects, and small objects warp less than large objects.

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Thanks for the replies folks, keep them coming. I was actually talking to a customer today about warping and when he asked about making it thicker I mentioned that that could actually make it worse rather than better. I tend to use linear fill most of time anyway, and have experimented with altering the angles but without any conclusive results. Circles rather than squares makes sense and I’ve seen this from observation; I too have used small thin cylinders on corners although you have to be careful that it doesn’t cause too much disruption to the perimeter. I suspect there’s math behind why they’re less prone to warp than sharp angles, but it’s beyond me.

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Second what @wirlybird said! These are sometimes referred to as “mouse-ears” and they really do make a huge difference when printing large objects. I use these in combination with ABS slurry, and rarely have warping issues with larger prints.

MakerBot has some nice examples here, and they can be easily implemented using any parametric modeling software.

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Hi @Enza3D slurry is pretty much the only sticking solution I’ve not tried so far, do you have any secret recipes or best sources?

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If you are willing to invest you could try a printinz board (http://www.printinz.com/). I use these on all my machines and there is no cleanup involved. Only thing I ever need to do was apply a little of the purple elmer’s glue stick to the printinz board I have installed on my printrbot and haven’t had to clean it off yet after months of use. Other two machines I never needed to apply glue to the boards.

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@cobnut,

First, I only use natural ABS to make my slurry. This way every object I print (no matter the object’s color) gets a nice glassy bottom finish and isn’t discolored by pigment in the slurry. Having a black print on a white-ABS based slurry leaves the base of the print marbled black/white which is fine for some prints, but not when the base is a visible surface once the print is done (i.e. model was printed on it’s side, so the base for printing is a visible surface once removed from the plate).

I generally go for a 10:1 ratio of acetone to ABS, by volume (this isn’t an exact science and I generally just go by consistency) . Essentially it’s the consistency of skim milk by the time the ABS dissolves. This seems to work really well; the parts come off nicely and the slurry is strong enough to hold the parts firmly.

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Glad those Printinz boards worked for you. I would have better luck getting it to stick to Teflon than those boards. Companies customer service was almost non-existent.

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The only true solution that actually addresses the cause of the problem is an enclosure. Aside from that, brims help, “mouse ears” on the corners(like @wirlybird mentioned) help. I print some very high temp materials like PEEK (+400c) and the amount of warp can be extraordinary unless you literally turn your enclosure into an oven. In my efforts to over come such extreme warp I have noticed some interesting things. For example, the infill pattern definitely has an impact. On solid infill, I have noticed that rectilinear warps more than concentric.
-Jesse

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I use 3D-EEZ on my glass plate. My MendelMax 3 came with a small bottle of it and I’m still using that bottle, since Dec 2015. It is water based, so cleans up with water. I’ve started printing more ABS lately, and I actually diluted it with water which makes it go on really smooth, and gives me a nice finish on the bottom of the part.

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Thanks @MindFuLL my current printer is enclosed but I’ve seen warping with it “shut” and none when open, a lot seems to be so dependent upon the model and the “stick” that the enclosure is only one part of the equation and sometimes, possibly, not a large part, if you see what I mean.

It would seem to make sense that if we all agree that “mouse ears” work, and that generally speaking round objects warp less than rectilinear ones, that a concentric infill pattern might also be a good way to go. Worth some experiments I think!

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I think it’s really important to make a distinction between fighting warp and preventing warp.

If you are fighting warp then you are just trying to make the parts stick to the bed. I can make any material stick to a bed but it doesn’t really solve the problem. On a large solid part, even if you get perfect super strong bed adhesion, it can just end up delaminating(splitting at the layers) because the warping forces are still building up inside the part. This also means that the part can look good while stuck to the bed, when it’s actually warped. It’s just being held flat from the adhesion and takes its real shape when you pop it off. Also, this does nothing for overhangs without a ton of support, which causes more warp.

If you want to prevent warp, then you are trying to make the part cool more slowly and uniformly. I hate warp as well and this is where I like spending my time & energy.

Your experience with the enclosure might sound counter intuitive to what I’m saying but you have to think about it more than just enclosure vs no enclosure. Getting this right for a specific material takes way more effort/experimenting than getting the right temp dialed in for the extruder or bed. You need to control the temperature AND the AIR FLOW. If you are using cooling fans or enclosure mounted fans to control the ambient temp, this gets way more complicated. For example, the enclosure can actually make air swirl around your print that would normally just flow past the part in one pass.
Obviously, every material is different. I print some materials that need to cool over a 24 hour period in 10degree increments if I want zero warp.

-Jesse

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