Hello reprap world! and the ceramic slib printhead

Hello Reprappers!

This is my first post so lets first introduce myself:
My name is Dries and I am an independent designer from Belgium. I studied at the Design academy in Eindhoven, Netherlands where I developed a strong interest in computer aided design (or what i call 'human aided' design). Unfolding complex 3d objects like a 3d scan of my own body into flat patterns which could be recreated from any sheet material was one of those techniques that I have been using since then. Besides being a designer I'm also a lecturer at the Fontys University of Applied sciences in Eindhoven, department of ICT and Media Design.

In June we plan to do an exhibit+project in New York with several other designers and institutes titled Bits and Pieces which focuses on the roll of design/the designer in the post-digital era.
The aim of the project is to start a longer lasting relation/cooperation between designers, researchers, institutes and artists. The show in NY will be rather small, a version 1.0. Later that year it will go to Eindhoven and Hasselt (belgium). It won't be the same show, it will evolve further and new connections and iterations will be made, v2.0 and 3.0.

For this project our design office plans to work on an idea we've been toying with for some time but never took the actual effort to develop. The (ambitious) plan is to develop a 3d printer that can print slip porcelain which can be baked into usable household ware. We want to present not only a final product but more a scenario to the public and visualize future possibilities. Connecting something high tech as a 3d 'desktop' printer with an age old craft technique that produces very familiar objects is something we want to dive into and experiment with the results of that merger. The project will be presented as a collaboration between the open community and its individual contributers and our studio since we strongly believe in open networks.

Two weeks ago I went to FabLab Utrecht to talk with Erik de Bruijn who's very active in the Dutch RepRap community. He showed me his printer build from casted parts. It was pretty clear to me that building a RepRap from scratch was something I would very much enjoy to do but was not a feasible thing to do for this project. We would rather focus on developing a toolhead for depositing ceramic slip then to spend most of my time searching for parts and building the Cartesian robot. This would be more interesting for the community too in our opinion.

So here we are, we talked to Ian from Bits from Bytes and ordered a reprap kit at his shop and we are planning and researching a printhead for ceramic slip. I'm also talking with the engineering dept. of my university for support. While not an easy task, we are thrilled to start experimenting with the reprap, various printhead ideas and ceramic slip recipes!

Any tips, help, printhead designs etc is very much appreciated.

Kind regards,

Dries

ps. I posted a topic about the design of the printhead in another section of the forum, lets discuss the specifics of printing clay and possible designs for the printhead there.
EDIT: link to post -> [forums.reprap.org]

Edited 1 time(s). Last edit at 02/02/2009 02:57PM by unfold.

Nice to hear about you Dries.

I was wondering when you are coming to Eindhoven and Hasselt. I am currently studying "bachelor of Product development" in Antwerpen and it would be nice to see what Bits and Pieces would be aiming at...

Welcome to the forums, and also post something in the dutch corner while you're here

Thanks Mr. seeker.

We're still in the early planning stage. Eindhoven will be in sept-okt-nov timeframe at Strijp-S (the old Philips factories in reconversion). Belgium, early 2010 in Hasselt or maybe Genk in cooperation with Z33. But thats very preliminary, first NY

Antwerpen, fijn! Wij ook... Ben je eentje aan het bouwen of heb je hem al af?
Even in het nederlandse hoekje posten.

You might look at the "paste extruder" design we made. This only holds a small volume of slip, but might work for you:

[reprap.org]

Having used it, I can say it would probably be easier to use if you just fitted a standard tyre valve to the top of the bottle and forgot about the lower pressurisation tube.

Vik :v)

How about using an electic caulk gun to extrude the clay?

You would have a lot more volume and easy reload with prepared cartridges.

Quick link to a picture:

[forums.reprap.org]

Just a quick update to keep you posted:

Ordered a BfB v3 machine a few months ago and the xyz bot is up and running since yesterday. Next step is the extruder and when thats finished I'll try to print some parts for paste extruders. Lovely toy, lovely tool! Mmm, that makes it a tooyl

Edited 1 time(s). Last edit at 05/05/2009 09:41AM by unfold.

Hello unfold,

did you do any further development regarding the printhead for ceramic slips?
I'm curious how you are going to construct the reservoir and the feeder. I was taking a look at the paste extruver V0.1- but thats not really matching my ideas of a printhead. I think maybe its not very suitable for the use with a slip.

btw: i saw the exploded extruder in your gallery- how did that happen?


best regards
Walter

Could you use a simple hydraulic gear pump to 'pump' the slip to the nozzle and a 3 position 3 port direction control valve and a water tank to wash out the pipe when its completed.

... the hard and abrasive particles in most ceramic slips would damage the pump, so you need another design (e.g. a peristaltic one) or you mix with microspheres which are round and smaller in diameter than the gaps.

Viktor

Hey, I got some delays on my plan for the ceramic print head. The good news is that the reason is that I have a ABS extruder and that I am still happily exploring the possibilities of that! In short, I am no engineer so developing something totally new is a bridge too far for me but I am working on a syringe tool with which i can explore the properties of the clay (which is more my domain).
The step after that is an extruder with a larger reservoir like the paste extruder or a peristaltic extruder.

@walter, we have absolutely no idea how that happened, all theories have some major BUT that make it improbable (reminds me of HHGTTG's improbability drive). The head is now of to Ian from Bits from Bytes for dissection. He wil cut it open to see if the head failed or if the firmware failed somehow.

I guess the peristaltic pump design could be a good choice. An other possibility would be to ground down the abrasive particles a little more in a ball mill like it is used for glazes- before mixing the ceramic powder with water. But maybe that also won't do the trick.
...the next problem seems to be that the extrusion nozzle will also wear out pretty quick. Maybe a nozzle made from SiC or similar will work.

@Viktor: what kind of microspheres do you mean? I just thought of this ballotinis they used for coating street signs A problem that will arise from adding additional materials is that the compatibility of slip and glaze, and also firing-temperature and stability of the objects while firing, will change. That would mean a lot more work.

@unfold: good luck with the syringe tool. I think a big advantage is that you can control the pressure very precisely- better than with a bicycle pump in the paste-extruder0.1

btw: the LSD-machine from the TU Clausthal-Zellerfeld seems to use a reservoir similar to the paste-extruder: a plastic container with slip set under pressure by air, pushing the slip into the nozzle system that is layering the slip onto the building table.

Walter

Hi Walter,

... i use hollow glass-spheres (=eccospheres from Trelleborg) around 50 microns in size until 400 centigrades, solid glass-spheres around 100 microns (until 1000 centigrades) or molten rock-spheres around 200 microns (until 1500 centigrades) from Sil-trade mixed with waterglass.

There are some comercial mixtures based on waterglass with talkum and different additives for temperature-ranges until 800 centigrades, which could be 'stretched' with water and/or waterglass and used als clay too ...

Viktor

Thank you for the detailed answer Viktor! So you are using the spheres instead of ceramic/glasspowder to make the slip not wearing/clogging the nozzle. And the waterglass as electrolyte is for making it even more flowable?
I also found your other thread from march about ceramic slurries. Now i see why you were adding the temperatures- your not going to sinter the pieces.
Because thats something i will need to do, Trelleborgs Fillite (Aluminiumoxide-spheres) seem more suitable for my task. Their melting temperature is about 1200-1350 centigrades.
I guess i will have think about it very well...

Walter

MasterLuke Wrote:

>
> @unfold: good luck with the syringe tool. I think
> a big advantage is that you can control the
> pressure very precisely- better than with a
> bicycle pump in the paste-extruder0.1
>
> btw: the LSD-machine from the TU
> Clausthal-Zellerfeld seems to use a reservoir
> similar to the paste-extruder: a plastic container
> with slip set under pressure by air, pushing the
> slip into the nozzle system that is layering the
> slip onto the building table.
>
> Walter

Thanks Walter! The link to the LSD machine is very interesting, they still use a laser for sintering as far as I understand. Looks like you have some decent knowledge on ceramics, industrial?

In case you haven't already found this, heres the link to a video about this machine: [video.tu-clausthal.de]
And, yes its a laser sintering machine. The Quality looks great- very detailed- a nice resolution. Maybe I'm going to go there and have a look myself...
It would be interresting as well, which kind of slip they are using- i suppose its some kind of alumina-ceramic.

I did a little more research and also found this machine:
[www.sandia.gov]
Its using a syringe, ceramic slurries and is putting it down layer by layer.
Theres one company using this technology. You can find it here:
[www.robocasting.net]
The products look a lot different from the one on the sandia homepage.
But at least the syringe-method is working with ceramics

I'm not really industrial- but studying Industrial Design for
ceramics and glass And i'm right in the middle of
my diploma. I don't know that much about mixtures of ceramic
slips or chemical calculations, more about processing it.

Walter

Hi Walter,
Thanks for the links, forgot somehow to follow my own topic so a bit late.
I know the work of Marc Ganter at Open3DP and some others that I should digg up and add to this topic.

But Robocasting looks recent because I have been looking around the net for ceramic Rp and never found much close to what I want to do but this looks exactly the same! Maybe good that I didn't see this earlier because my motivation to continue would be low.

Actually I am pretty sure they have been looking at RepRap when you see that minimug.

You can check my progress at UnfoldFab and see similar results although much more low tech.



Edited 2 time(s). Last edit at 01/16/2010 06:13AM by unfold.