The Physics of why your 3D Prints Warp, and what to do about it

[@theresinsamurai4520]

Thank you for the math that reinforces what we all think occurs. Running primarily ABS, it was a must to have an enclosure and running higher bed temps. I'm running 250c on the nozzle and 125c on the bed (Creality CR10s-300) currently with outstanding results just incase someone else is looking at the same setup~

[@franksonjohnson]

Just yesterday my roommate asked me why prints warp and I only had a vague, soupy answer. Thanks to you my answer has cooled past the glass point and solidified.

[@antalz]

Hehe, nice one. Thanks for watching

[@jesuschal3802]

What about increasing the temperature of the bed after first layer (or X first layers)? How much would it help?

[@Larock-wu1uu]

Great explanqtion, thank you! A follow-up video where you explain the effect of bed heating would be awesome.

[@MihaiDesigns]

Awesome explanation!

[@antalz]

Thanks once again!

[@marsgizmo]

very well explained 👌😎

[@antalz]

Thank you!

[@laboratoriodorato6910]

I wish I had teachers that made me this interested on classes. Great explanation, now all the heated enclosures makes sense fo me (beginner at 3d print). Thx for the great video

[@antalz]

Thank you, and thanks for watching

[@omnicogitosum]

Good job!. Thank you for this explanation.

[@Redo3D]

Thank you for this amazing explanation! The only part I am a bit confused at is when you said you can reduce the extrusion rate in order to close the gap in temperature difference between the new and previous layers. I understand increasing the temp will allow the previous layer to catch up before the first layer reaches tg temp, but m confused on how reducing extrusion rate would have the same effect? Thank you again for this video it has really helped my production. I have found that printing at 205c vs 190c the pla prints tend to be less heat resistant and have a lower tq the hotter you print them. I reduced my print speed to 75mms @190c from 90mms and it did reduce warping a bit. If I had a volcano nozzle with a much larger melt zone would switching to that and going back to 90mms have the same result? Curious your thoughts and I appreciate any explanation to help with my confusion

[@antalz]

Basically when plastic comes out of the nozzle, it isn't quite at the same temperature as the nozzle, but the slower plastic is extruded, the more time it has to get as close to the nozzle temperature as possible. In that vein, getting a volcano style nozzle should definitely help. That effect on softening temperature is quite interesting too.

[@EphiBlanshey]

Thanks for the clear explanation. Can you please clarify why printing slower would make a difference? Assuming the ambient, nozzle, and bed temperatures are the same, printing slower would still yield the same temperatures all around, no? If anything it would start laying down the next layer sooner before the previous cools down more.

[@antalz]

By printing slower the plastic flowing through the nozzle has more time to actually get up to the nozzle temperature, if you print fast the plastic comes out slightly colder due to limited thermal conduction inside of the plastic itself.

[@EphiBlanshey]

@@antalz that is an excellent point! Thank you for the response.

[@ThVG]

Great explanation. I assume it wouldn't matter on smaller prints, but would printing the second layer when the lower layer hasn't fully cooled yet also prevent warping, or does the lower layer reach ambient temperatures too fast for it to matter even on smaller prints?

[@antalz]

It could help, but its difficult to control. From thermal imaging it seems the temperature drops down within 3-5 seconds, so you can only do this for parts with a very small XY crosssection. Even then it's hard to balance, if the lower layer is too soft when a new layer is deposited, material can flow into unintended places. You can notice this when you print very small PLA parts, or the chimney of the 3D benchy.

[@stefanguiton]

Excellent breakdown!

[@antalz]

Thanks!

[@frankdearr2772]

great topic, thanks 👍

[@woodwaker1]

A great explanation, makes sense. thanks for doing this video

[@antalz]

Thanks, and thanks for watching

[@GustafB]

The idea with IR lights on the hotend is really interesting, does anyone know if that has been tested practically and what results were?

[@antalz]

I'm not aware of anything, I only know of NASA aiming halogen lightbulbs at a print, so they could print Ultem on a cheap printer.

[@SniperAngle12]

This is weird but i was printing a 3dbenchy and encountered a problem I've had for a while now. My set up is a 0.4mm nozzle ender 3 printing PETG mostly at a bed temp of 85~90C cause i find it gives better bed adhesion, and the issue is that on certain prints I would get this absolutely horrendous warping ~6-8mm above the build plate. Any sort of corner would just begin to curl up and inwards on itself, and I tried everything suggested in this vid short of using an enclosure. I even slowed prints all the way to 25% and i still get this warping. Curiously, it seems to happen only for thinner layer heights, when i bump it up to 0.24 and above, this problem reduces or goes away entirely, but thats obviously not a good fix for the problem. i don't have this problem on my much faster klipper printer either, regardless of the layer height at the same bed temps. I read something in a comment on another video, which was to lower bed temp, i tried it, lowering to 72C and that reduced my warping by a lot. Whats the explanation for this? Obviously closer to the bed, the high temp reduces warpage, and at a certain height, the warping would initiate due to the lower temperature, but why does it diminish when i use a lower bed temp from the start, very fast print speed or thicker layers?

[@TurboRetard]

If top layers cool faster it will pull the edges upwards and inwards. Solution I found was to not use the part cooler unless printing overhangs

[@TurboRetard]

The effect dimishes when you lower bed temp as it reduces the difference in heat between the lower layer on the bed and the upper layers cooling faster as they build up from the base.

[@Felipe-tw1wg]

So it seems more temperature at the hot end would reduce warping by increasing the lower layer more closer into the Glass Transition temperature, and hence, let it flow instead of curl? Seems counterintuitive but interesting nonetheless... I will try it out tonight with a warping print that is driving me nuts. Thank you for the explanation!

[@antalz]

It doesn't really allow the lower layer to flow. The idea is to warm up that lower layer, so that it thermally expands. Once the new layer cools down to the point it can no longer flow, it fuses to the lower layer. But the new layer will still be hotter than lower layer, so they're both solid and fused, but the upper layer has to cool down more to reach the ambient temperature than the lower layer. Because of that the new layer thermally shrinks more than the lower, and this difference in shrinkage causes warping.

[@MihaiAndreiStanimir]

You can upload this on IGTV so we can share it on Insta 😉

[@antalz]

Maybe I should spread out to other platforms too, I only post quick pictures on Instagram mostly.

[@DavidSanx]

Brilliant!

[@antalz]

Thank you

[@grzesiek1x]

what if the print is warping to the top , not bottom? Everywhere on youtube everybody shows the same thing but actually in reality there are some other deformations, which are preventing me from buying a 3d printer! I use it sometimes when it is available but never bought one because of that. If I have to print a part that has to fit perfectly into something and instead of a straight line looks likne a banana it doesn't make any sens to buy a 3d printer. Everbody prints usuless things but it is very rare that somebody prints something usfull but in this scenario you can see the reality what 3d printer has really to offer (or not).

[@antalz]

I can't tell what problem you're having. You may have a warped printbed, you can check that with a straightedge. You can also have off angles if the axes aren't perpendicular to each other. I don't know how you can get curved lines though. What exactly do you mean with warping to the top?

[@MauricioHernandez-de8is]

There Is a commercial 3d printer with an array of uv lights, have u seen it?

[@antalz]

I haven't, and UV sounds like a strange choice. Do you have any more info, a name or a link perhaps? Sound interesting.

[@nhoenderop]

🙏

[@pixiepaws99]

The exponential temperature decay is due to the nature of thermal energy transfer being proportional to the temperature via W/m·K, not because of your explanation.