Beautiful exploration, nice to see both the successes and the failures. Of course the real solution is to use the proper mold release agent and make a proper mold design. The reason why the cups didn't work out as well can be solved by using the correct mold release and by cutting the outer and inner shells into parts along the lengths. Usually some type of clamping system is used with molds that compress the parting lines together. I think with making these two changes, it would've been successful even with the PETG molds. TPU is a nice solution but it depends on the thing you are trying to cast. In a lot of examples we use a 'mother mold' to prevent deformation of the cast due to using a softer mold. A mother mold is like a hard shell that the TPU mold would sit in to retain the base shape. This is especially noticeable with larger casts. And even a necessity on silicone mold casts as silicone tends to deform a lot.
Wow. Spent the whole week going through EXACTLY the same steps as you did. I even had the same idea adding the cross section to grab on in the inner mold. Wish I had watched your video before...
Thank you SO MUCH for showing your failed moulds as well. I have been going through the same problems and begun to think it only happens to me. All other videos I've seen on UA-cam only show perfect working moulds and mine all stuck. I didn't understand why I was the only one with this problem. Thank you so much again. You gave me the courage to get back to it :)
Was doing some research on concrete casting with 3D printed molds and found your video! Great work! I hope you explore this medium further. You have a new subscriber 👍🏼
Form release, or even a thin coat of Vaseline will prevent your molds from sticking. The cross bracing you put in the first pen holder mold made it too rigid to remove. You want to do your best to pull the mold away from the surface and avoid sliding the mold along the surface.
one time i 3d printed a mold for concrete, i made the mold walls very thin and easy to break. the walls you made for the first print were very thick. yes this way you can't reuse them
Is there a particular reason why you 3d print the actual molds? If you learn a little about working with silicone you can 3d print the shape of the actual piece, sand it and then make a silicone mold using that shape as reference, that way your molds will be flexible and you will have an easier time demolding and making pieces that are simply imposible to demold wit 3d printing without breaking the mold.
I guess you’re right. I haven’t tried silicon casting but I know about 3d printing. That’s why. ;) But as you’ve saw in the video, TPU molds are reusable.
Have you thought of buying an extremely low grit diamond sharpening stone for flattening things? The ability to use your bodyweight to press down makes it extremely fast compared to filing it in the air. I know this from woodworking. On a side note, I'm impressed by the tight tolerances of your 3d printed parts.
Seen others using paintbrush and a small amount of Vaseline with good results. Simply brush the form inside before filling it with concrete and it will slip much much easier.
You also need to focus on your cast form. It's important always to minimize the contact between form and concrete. With 90 degrees or straight walls the concrete is always in contact with the walls all the way out and can make it difficult. Walls with 10-15 degrees angle, you only need to push a few millimeters before it slip because of the angles combine that with vaseline I think you can go back to your previous attempt concrete form in the start of video
That's what I thought, but with round objects, the force should be equal at any point... I might give this a try. I also had the Idea to just use a single TPU shell added to a normal PLA mold, maybe this will make the separation much easier?
@@eliwebinger7737 I believe there were people who tried that with a great success. Also, people have suggested making a silicone mold, which could also work great although it involves working with somewhat messy process. Whichever you try, good luck!!
Not sure if you'd consider it cheating, but you'd probably be better off printing male plugs, using those to cast female silicone molds, then casting in those. Demoulding a solid piece from a flexible mould is much easier.
@@Tinker_Box No problem! A good rule of thumb I got given years ago is that if you're casting rigid parts, use a flexible mold. If you're casting flexible parts, use a rigid mold.
you are missing a point. You need to take a silicone mold from the 3d output and pour the concrete into the silicone. If the material is thin, you should use the 3d output as a core. If you search for a silicone concrete mold, you will come across it.
Beautiful exploration, nice to see both the successes and the failures. Of course the real solution is to use the proper mold release agent and make a proper mold design. The reason why the cups didn't work out as well can be solved by using the correct mold release and by cutting the outer and inner shells into parts along the lengths. Usually some type of clamping system is used with molds that compress the parting lines together. I think with making these two changes, it would've been successful even with the PETG molds.
TPU is a nice solution but it depends on the thing you are trying to cast. In a lot of examples we use a 'mother mold' to prevent deformation of the cast due to using a softer mold. A mother mold is like a hard shell that the TPU mold would sit in to retain the base shape. This is especially noticeable with larger casts. And even a necessity on silicone mold casts as silicone tends to deform a lot.
It's great to see how you have improved your process. TPU looked much easier and the molds can be reused!
Wow. Spent the whole week going through EXACTLY the same steps as you did. I even had the same idea adding the cross section to grab on in the inner mold.
Wish I had watched your video before...
Happens me all the time, ha ha. Hope you came up with your own successful recipe!!
Thank you SO MUCH for showing your failed moulds as well. I have been going through the same problems and begun to think it only happens to me. All other videos I've seen on UA-cam only show perfect working moulds and mine all stuck. I didn't understand why I was the only one with this problem. Thank you so much again. You gave me the courage to get back to it :)
You’re the best! Thanks is mine. 😄👍
Thank you for sharing your experiences with moulding concrete. Very interesting. I certainly learned a lot from it 😅
Was doing some research on concrete casting with 3D printed molds and found your video! Great work! I hope you explore this medium further.
You have a new subscriber 👍🏼
Glad that you liked it and subscribed! Thanks!!
Great to see the trial and error process!
Thanks!
Form release, or even a thin coat of Vaseline will prevent your molds from sticking. The cross bracing you put in the first pen holder mold made it too rigid to remove. You want to do your best to pull the mold away from the surface and avoid sliding the mold along the surface.
Let the pot rest under water for a few days, and use some metal wire inside to reinforce the pots.
one time i 3d printed a mold for concrete, i made the mold walls very thin and easy to break. the walls you made for the first print were very thick. yes this way you can't reuse them
Very interesting!
Thanks!
i appreciate this video big time, excited to explore this myself
Thanks a lot. I'll follow up with one more project in this topic, so please stay tuned!
Such patience. Or maybe it's, ultimately, optimism.
Calming and great
Thanks:)
Excellent video. Thank you.
Thanks for the comments!!
It's really worth snipping those strings :D
my wife used some hand cream to wet the mold surface in order not not make the cement stick, it actually worked pretty well
Was there no coloration? Thanks for the info
@@Tinker_Box you mean if it altered the color? I believe not but anyway it was some hobby mortar cement so the color is pretty crappy already :D
@@samuelevinti You’re right.
thank you, i am thinking about some vibration device against gaps and printed inlay reinforcement
Very nice. Isopropyl alcohol helps dissolve hot glue just a fyi when you were taking the mold apart at 15:04
Great and thanks. I'll try that.
Is there a particular reason why you 3d print the actual molds? If you learn a little about working with silicone you can 3d print the shape of the actual piece, sand it and then make a silicone mold using that shape as reference, that way your molds will be flexible and you will have an easier time demolding and making pieces that are simply imposible to demold wit 3d printing without breaking the mold.
I guess you’re right. I haven’t tried silicon casting but I know about 3d printing. That’s why. ;) But as you’ve saw in the video, TPU molds are reusable.
Great video learned a lot from your mistakes 🎉
Thanks!
Have you thought of buying an extremely low grit diamond sharpening stone for flattening things? The ability to use your bodyweight to press down makes it extremely fast compared to filing it in the air. I know this from woodworking.
On a side note, I'm impressed by the tight tolerances of your 3d printed parts.
I have been using only sandpapers when sharpening the tools. I'll try those definitely. Thanks for the tip!
Great video! What concrete did you use?
@@Andrew_Chao That’s just some Korean brand, for generic interior finish. 😉
cold water foies inside, hot water outside
A blow torch from 8" away would have heated the PLA to soften to remove the cup mold.
@@InsidiousDr9 Only if I knew there was no way to salvage the mold.😉
You might try using the molds to create silicone positives and casting the cement from the silicone molds.
That’s an option. Thanks for the tip!
thank you for your mistakes
i have learned much
You know what? I also use my videos to avoid my own past mistakes! :) :)
Seen others using paintbrush and a small amount of Vaseline with good results. Simply brush the form inside before filling it with concrete and it will slip much much easier.
Really. I should try that. Thanks!
You also need to focus on your cast form. It's important always to minimize the contact between form and concrete. With 90 degrees or straight walls the concrete is always in contact with the walls all the way out and can make it difficult. Walls with 10-15 degrees angle, you only need to push a few millimeters before it slip because of the angles combine that with vaseline I think you can go back to your previous attempt concrete form in the start of video
@@lostbuddha7781 I actually gave it 5 degree inclination for that purpose. It wasn't enough, as you noticed. 😅
Have you tested TPU molds printed in Vasemode?
There were a few reasons why I didn’t use the vase mode. TPU is too soft and flexible so with vase mode it might deform at the weight of concrete.
That's what I thought, but with round objects, the force should be equal at any point... I might give this a try.
I also had the Idea to just use a single TPU shell added to a normal PLA mold, maybe this will make the separation much easier?
@@eliwebinger7737 I believe there were people who tried that with a great success. Also, people have suggested making a silicone mold, which could also work great although it involves working with somewhat messy process. Whichever you try, good luck!!
Not sure if you'd consider it cheating, but you'd probably be better off printing male plugs, using those to cast female silicone molds, then casting in those.
Demoulding a solid piece from a flexible mould is much easier.
Yes. Since I made this video, many suggested that and I agree. Thanks for your input!
@@Tinker_Box No problem! A good rule of thumb I got given years ago is that if you're casting rigid parts, use a flexible mold. If you're casting flexible parts, use a rigid mold.
@@peterhoulihan9766 Great tip! Thanks!! 👍
What is the Shore A scale of the TPU you used ?
I just used very generic, locally sourced, cheapest-you-can-get type. I got no info :(
Most common is 95A, so probably that
you are missing a point. You need to take a silicone mold from the 3d output and pour the concrete into the silicone. If the material is thin, you should use the 3d output as a core. If you search for a silicone concrete mold, you will come across it.
Guess you’re right!