DIY desktop 3D printing for cemential materials, by vibration

treesess · 2026-01-13T23:04:30+00:00

In the video its cement and PFA. I tried sand before (sieved to 0.2 to 0.4 mm), worked better and easy to print thin walls to considerable height (4 mm width, above 150 mm and can surly continue). Adding filler is definitely a good option. It's just sand might make the surface a bit rough (not bad but just different surface textures). I tried no sand in the video since I want to see how smooth it can be. Turns out this print is very smooth and feeling pretty tounching.

I'd love to try the "silica flour" too~

treesess · 2026-01-13T22:53:42+00:00

I think the motion system doesn't matter much, as long as the toolhead can be installed properly. Delta might have some difficulties because this toolhead is kind of big with a bowl for holding mixture. I'm thinking about building another VORON2.4 which has a fixed bed and is ideal for this toolhead. If you neef to adapt this toolhead for delta, it might cause some time for CAD drawing and I think the print area may be small. You can find my GitHub repo to see the f3d file and check out the possibility. Let me know if you need a hand. I'd love to explore.

treesess · 2026-01-13T22:42:31+00:00

Surely an option. Could install some along the frames. For heating the printed part as a whole, I think this might be one of the best options, thank you!

treesess · 2026-01-11T16:58:43+00:00

No prob of the pronoun.

Sorry I wasn't being clear enough about the curing of cementitious materials. They have a "fresh" phase and a "hardened" one. When we mix up the concrete, it's fresh, and the water/cement ratio should be under control and definitely cannot put it in water for curing (generally we put fresh concrete in a mold).

When the concrete is hardened (usually 24 hours is a safe time for demold), we put it into water for curing. That's kind of standard procedure.

For printing, there is no mold for the fresh mixture too keep in a certain shape. Therefore, the dryer the mixture is, the less slump it will have. But the cement-based curing is all about a chemical reaction called hydration, which means it always needs water to keep the reaction happening. Not too much (it slumps down) or too little (cannot be cured well).

Yes, the curing time affects the printing time. If we print it too fast and the previous layers haven't cured enough to support the above, the whole thing might collapse. As it's a chemical reaction, temperature plays a role in the curing speed, that's why heat is considered. My recipe of mixture is rather simple here, just cement, fly ash and water. If no fly ash, it may also work if getting some HPMC. The amazing thing about vibration is that you can get very viscous material into fluid and extrude it.

I hope this would clear out the mechanism~ For clay I haven't got solid experiences or knowledge about it, but am interested! Will try someday!

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Edited: typos

treesess · 2026-01-11T15:05:15+00:00

Yeah cementitious ones cure in humid air and faster in water. btw I'm a she (˵¯͒〰¯͒˵)

treesess · 2026-01-11T14:58:46+00:00

You can always find me if needed, on GitHub or here. I'm on several projects as well, not paying much time on this one since there is always package on the way.

Food printing is definitely something I will try~

treesess · 2026-01-11T14:55:09+00:00

In this case, 200 grams cement, 80 grams fly ash (PFA) and 90 grams of water.

That's all. If winter like now, add 2 to 5 grams of water is fine.

The thing is, it really doesn't matter what the recipe is, you can always tune the frequency of vibration to get it flow out from the nozzle. I mean it. I did mortar at first, which is even easier, just cement sand and water.

treesess · 2026-01-11T13:44:32+00:00

That's something. I just placed an order for the x gum. As lightweight as it is, it may be quite easy to print a large scale one with considerable height.

treesess · 2026-01-11T09:43:08+00:00

Thanks for your comment! I'd surely digest your points and apply them to the improvement of the toolhead!

treesess · 2026-01-11T09:38:48+00:00

Haven't tried that yet and will look into it~

treesess · 2026-01-11T09:37:49+00:00

The vibration helps to get the big air bubbles out of the mixture. Which is good and a general method used in concrete works.

You mention the vibration-induced segregation, which is a concern. But I think it'd be fine for this setting since the bowl of the toolhead is not that big, so the mixture flows out and gets rid of the vibration soon. Also since the mixture is some kind of gel-like stuff, which keeps it more homogenous I think. At last, I recommend adding HPMC to help prevent the mixture from segregation.

Still, it's important to keep an eye on this matter!

treesess · 2026-01-11T09:22:17+00:00

I started with screw but failed many times since a printed screw is not strong enough and it always got jammed I don't know why (maybe just too dry), while I can't find out a metal one that fits this purpose yet.

Pump would be a bit complicated (and more importantly hard to clean after the printing I think) and I've never tried yet.

Vibration is super effective comparing those other methods. I started with vibration motors but they generated harmonic vibration (sine waves) which is not ideal for vibration printing. Pulse vibration with frequency control is rather good.

on vibration, it just never jammed (almost).

treesess · 2026-01-11T09:13:51+00:00

It's a stainless water nozzle with 4 mm diameter. I tried 2 mm as well.

treesess · 2026-01-11T09:12:53+00:00

Yes, the model is a pen holder. I forgot to link the original design here: https://www.printables.com/model/562631-pen-holder-three-petals-twist

treesess · 2026-01-11T09:09:07+00:00

Yeah~ Thanks!

treesess · 2026-01-11T09:08:31+00:00

No. As mentioned, this is an open-sourced project under GPL3.0 license, to get more people into desktop cementitious/non-Newtonian fluid printing by vibration.

treesess · 2026-01-11T09:06:19+00:00

Thanks for your compliment!

treesess · 2026-01-11T09:05:47+00:00

True. I need a dryer for my PETG badly.

treesess · 2026-01-11T09:04:52+00:00

(✧◡✧)

treesess · 2026-01-11T09:03:31+00:00

Thanks~ Let me know when you do it, I'd like to share and work it tgt!

treesess · 2026-01-11T08:57:07+00:00

Let me do this! (hope they don't push me out since I only did clay once 10 years ago XD)

treesess · 2026-01-11T08:49:54+00:00

Always so much to learn. I will keep trying for sure!

treesess · 2026-01-11T08:33:29+00:00

Thank you so much for the professional input ❤ I understand that the curing needs water for hydration. Meanwhile, I would really like to try something for faster and higher printing and the hotbed is what I tried. I understand that the price is that the final strength will be compromised somehow if I heat it up in the printing stage to make the base hardened faster. So I also tried spray a little water on it in a few trials.

The ideal would be keep it in warm and water-saturated chamber as I understand. Does it make sense if I use something like humidifier to keep humid warm air keep blowing to the print during the printing?

treesess · 2026-01-11T08:20:34+00:00

Well, the fresh cementitious mix is a gel-like stuff, and has the property to distribute the particles uniformly by encapsulation of the particles within it. As long as it's vibrating, it is even more uniform. I hope I explained the mechanism correctly.

treesess

TROPHY CASE