3D Printers, Makers, DIY hacks, solutions and post printing tools

Created by Emil Pop on 13 April, 2018

Warping, what materials are prone to and how much?


The more elastic they are the more they are prone to warping, that is my personal assesment, hence;

PLA is little prone, nearly not a threat

ABS, damn prone, but controlable

PETG, worse than ABS (but considered less than PLA by novices), since it is so solid sticking to the bed that it might come off at job done with bits of the bed itlsef, and that saves the day except when you need to print a complicated geometry that requires supports made of another material (or good bye eliminating them after the print is done) and than you will see how prone to warping it is at the smallest gust of wind.

Nylon (actually by that we define a rather large category of polimers from Pe to PP to PET etc) is worse than PETG or ABS.

and the more up we go in temperature, the worse it gets.

Policarbonate, may the Lord have mercy on us if not printed in an enclosed chamber with controlled temperature

PEI (Ultem) same as Policabonate

PEEK, even worse than PEI.


But, the rigidisation of the filament with a mix of microfibers like Kevlar or Carbon Fiber reduces the elasticity and the tendency to warp by a factor sometimes of more than 50%, I noticed in my prints.


Remeber you always trade something for something else, nothing is coming for free, you stiffen the filament with fibers, becomes less prone to warp, more rigid, but the elasticity of non enriched filaments allows them to bend a bit and return to original form while the stiffend ones refuse to bend untill the breaking point, than snap.

Well except for the PEi and obviously PEEk that are much more robust and snap at far higher forces applied, but here you trade something for soemthing again, in orde to get that accomplised, your bank account goes dry each purchase you make in this category.


Now that you got bored in my preamble I can finally get back to the title theme.

Enclosures.


They seem to be the only way out of this mess but...

Stratasys secured a petent on puting a printer in an encloure that should of expired in 2020 in February, it did not because they found a legal glitch to prolong it another year, maybe next year they shall try again.


How, how on Earth they managed to obtain a patent on something that is comon knowledge (and a natural occurance too in some cases, these two things cannot be pattented, like water, natural seeds, rain, walking, the wheel, hot water, oil, bread, Pi x R2 and CO2 and H2O, and so on an so forth) hence their patent was illegaly obtained, probably against huge bribes called lobby, but fight them if you can.


However you are NOT a comercial operation, and the law is clear, you can reproduce or take advantage of any patent without being guilty of any infringement as long as it is not used in a comercial operation or as part of a way to make money either by selling products containg the pattented idea or by creating products with the pattented idea.


Hence if you are an Youtuber tha monetizes the channel you cannot present it on Youtube or you are in trouble big time. Because the ads in your youtube channel bring you a few dimes a day.


But they did not patented enclosing the printed object alone, unlike the entire printer.



Cocoon as you go type of enclosure:


And since that idea is mine and mine alone, and you are reading it online at my own choice tyo make it public, that makes it common knowledge, hece neither Stratasys nor anybody else starting today on (1 June 2020) can calim any rights on it and attempt to pattent it, not even bribing big time, because the line you read can be used against them on the spot, and for bilions of dollars of infringement of my rights.


But you can use it for your own good anytime, you have my permission, my blessing and I want you to post pictures thaken of your work and how my idea helped you.



This idea of mine is not "magic solving anything", so I expect you to fail often until you fine tune it for your own needs, hence no guarantees implied, zero, nada, nix, niente, rien, nimic, and whatever other language you might remeber the word for NO.


How did I came to it. By failing, obviously. And often.


I was printing some bits in PETG on the lenght of 280 mm and 170 mm width with a height of 90 mm, yep some one Kg of PETG per print, happy and trustworthy that PETG does not warp at all, just strings a lot.


Because of the sophisticated geometry I needsed supports that I could remove in tight spaces hence not well stuck to the print, so I choose ABS to do that job.


The sandwich was made of

  • an aluminium bed, heated at 60C permanently,
  • a layer of 3D printing compatibe film that although made in China and no name proved in the past 2 years a fantastic aid, sticking to the Aluminium at the point that to remove it I have to be careful when pulling not to bend my platter (5 mm thick of Ergal, nearly bulet proof solid)
  • a thin layer of slury Acetone in which I dissolved ABS (it holds damn well so that sometimes the print peels bits of film from the platter whan removing the part)
  • a brim of one layer and a raft of 3mm thick underneath the part, in ABS obviously.
  • and from there on up the part in PETG with all the needed supports in ABS.


ABS and PETG at 245C stick pretty well to eachother too, but not as well as PETG to PETG, hence removal of supports is not very easy, but much easier than PETG supports to PETG part.


All went fine for the first 3 hours, say brim, raft and about 3 mm of the part bottom; than I went confidently to bed. I wake up in the morning just to find the part warped up for about 2 centimeters from the bed at one end (exposed to air draft from my window) and the PETG was so glued to ABS that they went up togeher, peeling my protection film off the platter.


which caused the hot nozzles to drag against the surface plowing it


untill it hooked in it and lost a few thousand steps in the motors causing a layer shift of the printing algorithm and ending up by printing in the air a spagetty monster of filament.


I blamed it on the ABS on the spot, after all it is famous for being prone to warp.


I was right but I was wrong too.


Next step I ditched the ABS as support and went for PLA, not prone to warp.


While printing the new part in the same conditions, when I wake up next morning I noticed the PETG warped peeling itself off the PLA (aparently the PETG to PLA bond is far less strong, which is handy when removing supports)

But it did NOT peel everywhere, only where the bonding layer between PETG and PLA was exposed to air draft.

And where was it NOT exposed?

in the area where on top was supposed to be built a geometry bridged and overhanging at 90 degrees for one inch, there the PLA support material was like a wall just next to the PETG allowing zero air intrusion to PETG, and PLA that was taking the direct hit is not prone to warping.


So tomorow morning when this print is done I will re print the ugly warped part that got a payer shift that big that I could use it as a balcony.

Just that this time I go back in FreeCad, create a plan right above the whole drawing, and on top of it I will design a countour to my piece going out of the part for 5 mm with a thickness of half a mm, like a brim, but on top, without covering the part, just around it.

That in slicing will require support, and said support will be a wall stuck to the part, insulating it from any air draft.

Thechnically I am building an oven around my part, oven made by support material, at each layer, protecting my print in an enclosure built up with the print itself, disposable in the end, and of course I will have a "crown" on top of it that goes to trash, but saves my print.


Will add picutres in a few days when I will see if my idea has worked, this print is 75 hours long. Might even postpone it for the next week. But I shall do it anyway, just to check my invention.


First test went well.


Printing with an enclosure cocoon instead of a whole printer enclosure,

I printed 2 of the same part, identical but for one detail, one is free in the open air, and the other is cocooned in it's own support material to keep it from air drafts that could make it warp.

Although today was not windy hence the drafts are minor, and the part itself is low and short hence not that prone to warping, the part not protected warped a bit, not enough to make it useless, but warped enough to peel itself off the raft of white PLA with no effort.

The cocconed part was hard to get out of the cocoon, pretty stuck in there and zero warping.

It works.

I nrmally destroy the suports at the end to make their elimination fast, but not now, now I extracted the PETG black part out of the cocoon with outmost care, to save the cocoon too.

I need to print some bigger objects now, just to stretch this to it's limits, to find out how far can I go trusting this idea of mine.