Triple (x3) your Layer Strength by Annealing 3D Prints in Plaster!
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- เผยแพร่เมื่อ 15 พ.ค. 2024
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In the past, I've already tried many different techniques to fuse 3D printing layers together by annealing or coating but never had great success. This time I embedded PLA and PETG 3D prints in plaster and then annealed them at temperatures over their melting point to see if we can fuse the layers together and how their heat resistance changes. Let's find out more!
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Chapters:
00:00 Introduction
01:50 Test Setup
02:50 Embedding
03:56 Drying
05:00 Promo
06:34 Plaster Removal
09:00 Mechanical Tests
12:50 Temperature Tests
13:56 Summary
14:21 Outro
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Going forward with a sponsorship from Autodesk after the community response to their crippling of Fusion 360 seems like a bold move. Hope you could squeeze them for some hazzard pay for the risk to your reputation.
Great tests, as always. Thanks a lot :)
i dont understand why autodesk starts sposorings right NOW, when there is so much risk of the community hating them...
@@RedHotBagel Autodesk was under no obligation to continue offering Fusion 360 for free. Especially when there are quite a few who abused the free license by using it for commercial purposes.
One thing to test post process for the PLA is UV resistance. Typically this is where PETG shined over PLA, but if its handling heat that much better, maybe it's UV resistance is also increased?
@@vhoward1122 I can totally forgive that, its their insistence on a sub that killed me. I'll buy a piece of software once, I am not prepared to make it an extra monthly bill.
this man single handedly has helped the entire 3d printing community on multiple occasions, thank you Stefan
bruh he got 2 hands
Try heat resistant silicon molding. Will work in vacuum.
He's the Jeorge Sprave (I probably butchered his name, srry) of 3d printing
@@TommiHonkonen suomi perkele
There is another method using salt, looks like an easier solution to me th-cam.com/video/nRLJ4ylGTFc/w-d-xo.html
Before putting in plaster, coat with a sealer and then mold release. Avoids moisture absorbtion and reduces cleanup.
Good call on mold release and sealant.
In a pinch, try Pam cooking spray
wouldnt this mix up with the pla?
@@wt2009 Could do and that is what I thought when the same idea occurred to me, the chemistry would be complex, then again having thought about it another time it could help. Only one way to be sure!
@@mhartleroad i was thinking a quick dip in liquid paraffin wax would seal the part off nicely.
Use SALT. I get EXCELLENT and consistent results by doing this process in finely ground salt (ideally near powder, if you have the patience to grind it that fine). The finer the better. Pack a stainless steel container tightly with salt and the part. In the oven the salt kind of hardens and the part is not allowed to deform at all. After the remelting I just demold and wash the parts and the fine crystals embedded in the wall just dissolve. I'm left with a part surface roughness that is dependent on the coarseness (or fine-ness) of the salt. The solidified chunks of salt easily return to powder by crushing them with your hands and it can nearly be reused ad infinitum since you lose very little salt at every run. The parts are super strong and water/airtight. I use the technique mostly for printing watertight containers and small pressure vessels. Can do really thin walls too.
Beware, try to buy preground salt, cause grinding a few kgs of salt in a coffee mill or blender will overheat the motor (i broke my blender this way).
Feel free to credit me if you try the technique. Also take a shot for every time I said the word 'salt' in this here comment.
EDIT: I just made a video detailing the process and results. th-cam.com/video/nRLJ4ylGTFc/w-d-xo.html
This is actually really smart. When my Prusa mini finally arrives next month I'll have to try it.
Nice explanation!
@@CNCKitchen thank you for taking the time to read
Thats a nice idea. Do you think using road deicing salt is okay for this too, as it's way cheaper than table salt.
@@ProtonOne11 probably, though here in the Netherlands even iodized table salt is like 50¢/kg. The main thing is to use a stainless steel vessel, because a steel one will rust pretty quickly with the salt and heat, and will discolour the salt which I guess could transfer to your prints. Another thing is to pack it really tightly. If there are pockets of plastic that are not packed and properly immobilised they will sag and deform, so you should thing well about the geometry of the part during design.
The higher temperature capability of the PLA after annealing is the most interesting result from these tests.
I can think of endless possibilities
well we already knew that. but the 0 deformation is the real winner here.
Thats already been established in a different video he did
It's because of increased crystallinity, which has a higher melting point, because of its lower energy and therefore thermodynamic stability. This is to be expected for semicrsyatlline polymers like PLA
Exactly. A phone holder or sunglasses clip doesn't really need the full PLA strength to function as intended, just the ability to not melt in a car sitting in the sun all day. This would be perfect for those applications.
Hey Stefan! I did a bit porcelain casting back in university. This is the technique we used to get (mostly) bubbly-free plaster molds:
Start with water inside an somewhat wide and shallow container.
Slowly add plaster using a sieve and let it dissolve into the liquid. Don't stir!
Repeat until the plaster stops dissolving and is resting on the surface.
You can now give it a light carefull stir, but it does not need much at this point.
In the end the plaster should have the consistency of a thick gravy, which makes pouring it into your mold pretty easy.
Nice explanation.
The temperature tolerance improvement on PLA is astonishing. That is much more interesting to me, since we have so many techniques for designing and printing parts in their optimal orientation, but if the material fails due to temperature, then there is nothing you can do. So massive kudos for figuring out this step.
As a mechanical engineer that studies strengths and stress analysis (but now specialise is thermodynamics) I find this first principle practical approach first class. I use the same formats to show improvements or steps backwards. Overall very refreshing to see.
Hello,
I use the same technique but
with some difference:
1) I don't use Plaster of Paris,
but two-component silicone,
much easier cleaning.
2) I don't use vacuum, but
I put under pressure at 5 bar.
Have nice day. :)
nice but what were your results?
2 component adhesive is too ductile id say use investment its a type of casting plaster which melts away better in water
@@jakeengland1430 I think he's talking about mold silicone, not adhesive.
Silicone wont stick to anything beside itself so you can just cut the mold in two and remove the part. It might even be possible to reuse the mold, depending on part geometry.
@@jakeengland1430 i see thx
Yes!!! Brilliant!! in mass production!!! 3d printing it starts to get real big!
1. Coat the parts in a hydrophobic mold release.
2. Cast the parts individually in custom printed casting containers so there is an even plaster layer around the part. You will use less plaster and have more surface area to volume so the cast will dry quicker. More even heat distribution during annealing and the plaster may be less likely to crack.
3. Cast the parts with the container on a vibrating bed to agitate the bubbles out.
4. Use an ultrasonic bath to clean the parts. Maybe investigate if you can use IPA to dissolve plaster instead of water.
IPA? I know that India Pale Ale is disgusting to drink, but can it really be used to dissolve plaster molds?
Not sure if this is sarcasm, but IPA stands for Isopropyl Alcohol
Mark Carbonell - which, of course, you don’t wanna drink....
Great advice, and even better motors! Love ya guys
A hammer drill with a reversed bit can also be used for vibration.
Did you consider some type of release medium coating the part prior to covering with plaster? Like an oil or powder coat. Oil would also reduce absorbing moisture from the plaster.
This is similar to a suggestion I was going to make. Basically asking if using a mold release would help getting the parts out of the plaster.
@@Sembazuru It would also keep the plastic from absorbing water, and then creating steam during curing.
Great video! Try painting on a watered down layer of gypsum plaster to capture fine details. After letting it dry, paint a thicker layer of gypsum plaster mixed with sand. The plastic parts should heat up more quickly and evenly if you don't submerge them in a large volume of gypsum plaster. Besides adding strength, sand should reduce the degree of shrinkage, steam bubbling, and cracking that occurs when calcining gypsum.
I saw that bread and forgot what you were talking about....
That looks good!
CNC Kitchen
2019 - Tweak layers to make them stronger
2020 - This
2021 - "Today, I am going to show you, how to make your 3D prints stronger than steel using plasma vapor deposition"
(Not impossible)
That sounds basically like making the parts out of graphene and carbon nanotubes.
Omg that bread looks good.
I saw that bread... then thought about what we can get at stores here... and cried.
Always excited to see a new CNC Kitchen upload! This was really interesting and I'm curious to see how much you're able to improve the process. Prost!
By far the most thorough 3d print testing channel on yt, love this channel
I have annealed parts embedded in two-part concrete-molds made specifically for this purpose.
This way I can anneal many parts quickly, and there are no difficulty in inserting the parts or retrieving them afterwards.
This procedure is, off course, best suited for relatively simple geometries.
These are the kind of tests and experiments that will continue to take 3d printing to the next level. Thanks so much Stefan and also to those who left their experiences in the comments. I'm very excited to try these things out and to make 3d printing even more practical for mechanical applications!
This was a really well made video! Very easy to follow along, great pace, proper level of detail and it was entertaining and fun to watch. I just subscribed and I am going to check out your library and it will be great to see what you do next.
Really impressive results! As always, an awesome video Stefan!
Thanks for testing this! It seems like it should work for PETG with 100% infill and heat-resistant mold release. In order to avoid bubbles cover the parts with just a thin layer of liquid plaster solution. And when it hardens submerge it in bulk plaster.
Here is finds, you might know already. I was printing huge containers with PETG, first of all PETGs are different, but I found the one which sticks to hot glass without anything else. Sometimes after bed cooling down, tension in printed item is so high, that it cracks glass, so you need to remove it while it still hot. Secondly, I noticed that printing at highest temp without cooling for PETG makes it the most strength, if you break it it shattered as glass, so layers adhesion is equal to strength of material, but when you print at lower temperature without cooling and lower speed therefore, it retains it plasticity while saves property layer adhesion. So with this setting PETG is like welding to part, rather than placing layers.
When you print big parts, "places of welds" have a time to cool down, so if you want to print small parts you need pause printing after printing each layer, to let plastic to weld to each other. Also at high Temps PETG expands and while extruder on a side even with huge retraction, PETG will runout, as the result not enough/constant extrusion for next layer.
Like anyway.
I'll think about it!
I'm glad that someone did a video on this finally. I suggested it before, but I'm not sure which channel. Great video!
Really excited to see this, have been thinking about trying this for a long time.
How about leaving a port open to the infill and inject an epoxy into the cavities basically making the print 100% solid.
Hardening epoxy may melt or soften the part it they are pla and other low temp. filaments
The problem is most, if not all infills create blockages that would prevent the filling.
@@macrumpton Gyroid infill prevents this issue but im pretty sure someone on youtube already tried filling 3Dprints with epoxy and it didnt work well unfortunately
If I'm not mistaken, in a previous video Stefan demonstrated that epoxy frequently reduces the strength of the print itself . I got the impression that there was a chemical reaction between the plastic being used and the epoxy . Possibly in epoxy friendly filament could be made?
Epoxy is expensive. But if you have small, or high value parts, then it may be a good option. One application I can think of would be in 3D printed cnc router components.
I have never seen what settings you are using for PETG. I have found that the default profile for PETG in PrusaSlicer with fan on for all layers above 3 left me with brittle prints. Raising the temperature and turning off the fan (except for bridges and stuff) increased my parts strength dramatically. I don't have your test equipment or (more importantly) your patience, so I don't know much.
Thanks for all the great content and information!
Yeah it's interesting how everyone claims high interlaminar strength with PETG, but Stefan's tensile and Charpy tests show mediocre interlaminar strength and toughness. I wonder if these are related to his use of forced-air cooling. Perhaps rapid cooling results in a lesser degree of annealing, assuming there is enough time for some degree of annealing during printing. It makes me curious to see the results of PETG without fan, or PETG in a heated enclosure, without post-process-annealing.
genius technique, I've done lost pla casting never thought to just stop halfway and get a remelted but dimensionally perfect part 🤔 love it
I just started printing with PETG and I'm already impressed with its strength and resilience when printed correctly. I might try this annealing method and really give my parts strength
Great idea with good results, definitely warrants further testing of this process. You may want to try light weight plaster or using light weight fillers and an ultrasonic bath to make removing the parts easier.
I too was curious about using an ultrasonic bath for plaster removal.
Yes! Somebody's finally tried it.
This guy has done so much for the 3D printing space. Thank you!
My pleasure!
ive been saying for ages youtubers should use the new timestamping feature to make it easier to skip the adverts, thankyou for being the first ive seen to do it!
plaster of paris, as you noted, converts at fairly low temperatures, and includes a LOT of water. and as you heat it, and its converting back to plaster, its off gassing water into your part. this process may be vastly improved by replacing the Plaster with something else, maybe some kind of plaster slip or investment casting. it would be interesting to see the effects of a similar process using compressed green sand as well.
Good point! At 150°C the gypsum releases a lot of steam. Maybe it's worth letting it rest at that temperature a bit to dry it out, before heating it up all the way to the melting point.
@@CNCKitchen a smaller volume of plaster will also aid in drying times. you might try dipping the parts into a thin plaster and letting it dry then dipping them several more times to build up a serviceable thickness, but not a large block. then drying and soaking the mold for longer to bake off all the water.
my concern is that when you get over 150c the plaster is giving off steam, which is being forced into the plastic as the path of least resistance. which is why i think a non gypsum based plaster is the key, some kind of ceramic slip. but as far as i know most of them require very high curing temps which would decompose the PLA.
in another thread i suggest sealing the part with wax. perhaps sealing the part with wax, then a smaller total volume of plaster would allow the steam to exit the mold, and not enter the part.
Very interesting results! Could you perhaps use “green sand” instead of the plaster? It’s the type of sand that’s used for casting metals. I would assume it does niet contain water, and it seems to break away from the part relatively easy. Thanks for sharing all the great work!
Green sand for casting contains water. 2-4% according to here: en.wikipedia.org/wiki/Sand_casting#Green_sand
I don't think that would be hard enough. It would still move under warping
Great Experiment! Fascinating results!
Great results and nice bread :P Awesome work!
Make two halves so you can reuse the malls, just like casting
malls?
@@g60force I wonder if it's supposed to be molds and it is a typo
@@KJMcLaws In Dutch it's 'mal', so maybe a translation mishap
You should he able to dissolve away remaining acid with a weak acid like vinegar
Wow man you’re always thinking way outside the box. Super dope concept
This is great info, especially the temperature resistance, as most of my projects are for car interiors that get pretty dang hot in the sunshine in summer :)
you could try to make the molds just with dry gypsum only harden it with compression - it would be easier to remove and even better no moisture :)
Exactly, I was thinking the same throughout the whole video.
@@JC-wh7jj yeah. Salt won. I think. Would depend a little on surface texture but salt should be completely removable, gypsum might make problems when rinsing and salt is cheapest.
@@gur262 I don't quite agree.
Plaster/gypsum has one very big advantage - it is already ground into a very fine powder. And the salt grinding process looks like a very messy and time-consuming process, and might wreck your kitchen grinder, which is expensive.
For smaller quantities 0.5 kg, 1kg salt is indeed cheaper, but for 10kg, 25kg bags plaster becomes cheaper as a building material and we are talking about several bucks anyway.
Of course I'm talking about using plaster in its dry form, without water, just as a replacement for the powdered salt, added around the part and compressed by hand.
I agree that plaster might be more difficult to remove, not to breake thewhole lump, but just the fine lair in contact with the part that the plastic might stick to, and it's not soluble like salt.
@CNC Kitchen I believe I left one or two comments in the past, suggesting to use salt as an embedding medium. You can bond it with water and it is easier to dry and easier to dissolve. I will document my results better after my next test and share (I finally have my own 3D printer). It's something I would recommend to try. It has some significant advantages to plaster but also some disadvantages.
You can fill the salt inside your print (with suitable support) and only have a small opening to dissolve the salt on the inside. It makes post processing a lot easier
Also, you can have the process be a lot dryer than with plaster.
This is very interesting ... would definitively like to see a video on that topic.
it's all about heat resistance to me ! ..nice work i never thought of plaster casting them to prevent warping .. wonderful idea
Been waiting for a vid like this
I see Autodesk is attempting to deflect attention away from their poorly received changes to the Fusion360 licenses.
Yeah there was a decently length discussion about it on my comment about this exact same thing :)
Some people feel they can do what they want and others are disappointed
@@column.01 i think both are correct. they can do what they want and we can be disappointed. i just finally gave up and purchased solidworks.
After watching Angus' video about the major changes to Fusion 360($$$) I'd be reluctant to promote Autodesk. Great channel and vids regardless Stefan.
I watched free spirit’s video about annealing in table salt. he uses a coffee grinder to get the salt particle size very small for a smooth part surface, packs it tightly and then puts in an oven to anneal (re-melt) at 240C (PETG). Very impressive results, and the parts look great too
Way chill idea and results! :)
Any chance at that bread recipe? I can't say I've seen anything like it in the states.
Here you go (very similar to mine. Add Rasins for the extra kick): cookpad.com/uk/recipes/155897-hefezopf-german-bread
i dont understand why autodesk starts sposorings right NOW, when there is so much risk of the community hating them...
To try and get new users to make up for the thousands they are going to lose.
Why? Was one of their update failing or something?
Following for info!
@@totalwayne3089 the did not so nice things to the fusion360 hobbiest license
@@macrumpton but what are they really losing? They aren't making any money from the free users.
this is a brilliant idea you got sir!
i want more experiments on this, it might be a true gamechanger for some projects
Screw Autodesk, they're nerfing the free version of fusion 360..
Fascinating way to aneal prints though, never would've considered plaster myself.
Fuck Autodesk, they are limiting access to hobbyists, they treated them like early beta testers for Fusion 360 and now that they have a complete working product with a lot of people knowing how to use it the put restrictions upon it. They work just like drug dealers, getting you hooked up on their drug for free and then making you pay to use it. This is what they always used to do, i wonder why they took so much time to enforce it on Fusion 360.
I stuck with OnShape and am happy. Of course I learned SolidWorks first which helped. Hopefully OnShape won't fuk over hobby crowd later on too.
I'm going to play the devil's advocate here.
So is Autodesk supposed to develop and upkeep Fusion360 for free? Why?
What is wrong with keeping the product free during development, letting people use it, and then changing the licence once the product is more complete?
*laughs in pirated Autodesk Inventor Professional*
@@mr1enrollment you know what the terms of use of onshape is, i hope?
Excellent video as always, love to see the scientific approach to testing these things.
Also, I can't help but laugh at AutoDesk here, given they recently ticked off a good portion of the Maker community.
I missed that. What did they do to tick off the makers?
@@Kineth1 They are changing the rules on Fusion360 free version. I was just starting to learn it, now going to switch to another program, probably FreeCad.
@@woodwaker1
Ah heck what are they changing? I only just learnt F360.
@@jeffvader811 They are changing what the free license can do. There a lot of videos out about it. Here is one th-cam.com/video/5EOiuTu14tI/w-d-xo.html&ab_channel=TFI
stefan, you can use a vibration table (common in dental labs) for removing bubbles from plaster and increasing plaster cohesion. its a standard practice for dental models
Instead of molding in small buckets, mold them into a thin baking pan...keeps the plaster thinner, so it dries faster, and a whole lot less material to remove. Also allows the heat to transfer to the parts faster so you can spend less time heating up a huge block of plaster, and more accurately get the part to desired temp. Thanks for all the great work, really appreciate you!
What are your thoughts on the gutting of fusion 360 by autodesk?
Interesting; but, this seems to require almost as much effort as lost PLA and with lost PLA you get metal parts which are MUCH stronger.
But dont you have to have metal?
this has the advantage of not requiring a proper forge. Granted getting access to an anneling oven is also not easy, but is suspect just melting the PETG in a regular oven may get you similar results
@@zakkus You don't necessarily need a forge to cast metal. There are several alloys that melt a temperature low enough to use a kitchen oven or torch to melt them
At last I found you are the GreatScott of 3d printing!
One of the things I appreciate the most about my trade school is the free access to the full range of Autodesk programs, they're a must have and well worth the price if you plan on using design as a mainstay of a business venture
That amount of effort is exceeding injection molding though.
How much is an injection molding machine, and HOW much does it cost to get the molds made up?
So the effort goes into a life sucking job.
@@Margarinetaylorgrease I was suggesting making your own plaster moulding machine. Maybe I used the wrong terminology.
@@Margarinetaylorgrease De Crass Man over at the SteadyCraftin channel just bought a plastic injection-molding machine with a 1-cubic inch plastic capacity. It was a simple model, so it only cost two thousand US dollars for the base unit. Accessories are also expensive.
@@FranklyPeetoons Everybody should have one.
you can do this with uncastable geometries
try high temp silicone, and treat parts with mold release agent
I just watched a video about heating PETG with Salt powder. That may be another option instead of using plaster as it yeilded some pretty amazing results.
Thanks for the excellent work, this helped me a lot
It hurts my heart to see CNC kitchen promoting autodesk :( they are evil, EVIL i tell you!
Butthurt that they reduce some features on the free license of Fusion 360, are we?
Why I may ask?
@@ProtonOne11 I was kind of scummy of them, but it's their product, they can do what they want with it. I'll just look for something different.
@@Tunkkis totaly scummy to give away a 7k$ program for free
@@ProtonOne11 Nah Im not affected at all I don't use autodesk products but is surprising how many like to polish the autodesk knob and defend their shitty market practices.
"somehow it caused the water and plaster to seperate" oh lord. You know water boils in a vacuum right?
I already knew it was possible to anneal PLA into past 100c heat resistance but this right here.. Is just plain amazing.
Basically this means that PLA can be used for automotive intake manifolds and such. Amazing.
This checks every tickmark related to modern TH-cam video layouts.
First Like and comment, I can die peacefully
Wow the amount of talent this guy has is amazing.
Thanks!
Ha.... smart kid! Always a pleasure to look at your new clever idea!
Thumbs up before the introduction end.
Alex from Montreal
Hmmmmmm handicaps free version of fusion starts advertising other products more.🤔
Exactly.
They have money to donate to BLM, anti-police and organizations that hate White people though!
This with PC or even higher end materials like PEKK would be top notch!
Great video! thanks!
I've never owned a 3D printer, Never used a 3D printer, And never really wanted a 3D printer. I clicked on this video by accident !!!! ........ But it was interesting enough for me to keep watching all the way to the end. I'm impressed that you managed to peak my interest enough for me to happily watch a video on a subject I've got very little interest in. That alone was worth a like. :D
Right, I'm off to look for more videos on hobby grade milling machines. :)
I'm currently trying to figure out the price-to-quality curve on a completely unrelated type of product where not a lot of hard data exists, and it makes me appreciate Stefan even more than I normally do.
Great video. So useful information and lots of work. Mahalo for sharing! : )
動画見てたら、いつの間にかAutoCADのステマを見ていた。
いつも素晴らしい動画をアップしてくれてありがとう。
You could even print a tower around the print to prevent warping and just use the tower as a plaster container. Fascinating, as awlays!
I used to work at an aluminum foundry where we used plaster molds. We used a high pressure water jet to clean the parts. I also experimented with dissolving the plaster in a saturated solution of water and sodium bicarbonate (96 g/L (20 °C) 165 g/L (60 °C)). The sodium bicarbonate will react with the plaster so it's a good idea to oversaturate it. The experiments showed a great deal of promise. I don't know if the SB-solution would effect the PLA/PETG in any way though.
If you plan on making a lot of test hooks i would consider making a two part mold fort the plaster. That way you can dry the mold faster and be sure to have no moisture in contact with the plastic. You then put your printed test hook in your two part plaster mold, clamp it together and anneal. If the mold doesn't crack and your part doesn't stick to much (try mold release) you might be able to reuse the mold.
Nice results!
Only need a thin layer of plaster around the part to maintain dimensional stability. That will also make it easy to to remove water moisture. Amazing work my friend.
The same air bubble issue comes up when encaping electronics in epoxy. I'd love to see you try this again but use a pressure chamber on the plaster before you set it to dry. Could also allow you to go to much higher temps and print more complex designs. Just make sure you don't anneal anything hollow! :)
I also wonder if there's a hydrophobic coating you could apply to the PETG parts before dunking them in the plaster? It wouldn't need to survive the annealing process, just the dehydration, so pretty much anything would do I imagine, as long as it doesn't react with the PETG.
Great video. Do you know what density your prints had before annealing. Perhaps the air bubbles between the extruded lines join together?
You should do a compilation video of pure results so that it's the most informational video on 3d print strength ever
I've used this technique with ABS once - I dubbed it plaster self casting - and it seemed to work great. My wife's food processor (like a thermomix / hot blender) had a plastic coupler that wore out. The part undergoes a lot of stress, coupling the heated blender to the motor. I kept printing out replacements, but they'd last at most a couple of months before shearing along the z plane. The self-cast piece has been going strong for a year now.
I printed at 100% infill. For plastering, I kept the container small, kept the mix runny, sprayed the part with vegetable oil and spent 5 minutes manually jiggling and vibrating to get the bubbles out. I left it for over half a day for it to set. Then I bake 2 hours on high in the oven and left for another half a day to cool before hammering to get the coarse plaster off. Finally I soaked in vinegar and then used a water pik to blast the rest of the bits off. There was no evidence of bubbles or deformation, even on the finer gear teeth.
One thing that would be interesting to see: what happens if you use this on solid clear plastics - clear PETG, ABS and PLA?
If it's really re-melting inside, it should make these internal plastics fuse together into a single blob and it should become much more translucent and clear. Any takers to run the experiment? Maybe something cool like a crystal skull model?
Eagerly awaiting the “salt method” follow up to this!
When you wake up to “and welcome to CNC kitchen” you know it’s gonna be an informative morning
Impressive results! Would be interesting to know if the impact strength of the petg part has also changed!
Impressive test
Thanks for sharing 👍😀
The PETG results were fabulous; strength and ductility!!! This opens up some great options for structural parts........... the bread looked great tooooooooooooooooooo!
Brilliant application!
Stephan, You are my favorite TH-camr!
Wonderful and valuable information !
That's great news about the annealing PLA for heat treating. I tend to stay away from PLA for functional parts because I live in Arizona and the summer temperature frequently get above 120f. Parts made of PLA for e bikes or cars can't handle the heat. I'll have to try plaster cast annealing.
You had me at guten tag. You get a subscriber.
Thanks for a solid video and I appreciate the work you have done in the past. you’ve received many suggestions that may prove helpful in improving your annealing process. I cannot speak to most of them but I have a few decades producing ceramic molds and in using 3D printing for producing plaster molds for ceramic production. You had the right idea about putting the plaster in a vacuum chamber, but just place the wet plaster in there with out the plastic forms then pour the plaster into a container the parts are in. More importantly, don’t use plaster of Paris, use a high quality industry plaster like pottery #1, it won’t separate in the vacuum chamber and has significantly better working properties than plaster of Paris. I also recommend learning the process and timing for mixing it to achieve the best hi-fidelity and bubble free results. If you test using any mold releases I recommend a high quality mold soap but I am not sure how effective it would be at some of the temperature you are taking it to, but worth the shot. As I write this I do imagine oil based release might survive the annealing process a bit better than a traditional plaster mold release which is water based. Lastly, I appreciate the use of a food dehydrator, keep it slow and low. Plaster curing is a chemical process and it takes a while for the heat and moisture to work itself out, consider leaving the casts out in front of a common fan for a week, then dehydrating. none the less, good luck and thanks for taking this research on.
We dentists use a split mould technique. The description given by Seecalator on how to mix plaster is good, sprinkle it into water and let it soak it up, mix and then we would use a small vibrating table to get the air-bubbles out. Or bang the container on the bench a few times. Coat the print in a suitable separation medium and then place it embedded slightly into a layer of plaster that fills only half of the height of your container. Let it dry and then paint that layer with separating medium. If there are no undercuts in the model, fill to the top of the container with paster. If there are undercuts pour in a layer of plaster to cover the model and its undercuts. Let this layer set. Coat with separating medium and then fill to the top with another layer of plaster.
When you have annealed it simply seperate off the layers, usually by cutting a small slit into a layer and carefully splitting it. If I was doing multiple layers I would do the top, then the thin undercut layer while still attached to the based, and then free from the base.
There are solutions that will dissolve gypsum.
Good work chap.
Another awesome study schteffan.
You may want to seal the prints with a release agent before plastering. This, in theory, will help with cleanup (if it survives the high heat)... but also could prevent Hydrolyzing of the PETG.