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Posts by Sisko Roosenboom

Science Fair

A belated and concluding post. Our exposition at the science fair (26-okt) was a success. We are very satisfied with number of visitors and we are greatful for the interest that people took in our research. If everything goes well these results will also be shown at the congress for Urban Network for Innovation in Ceramics in may 2011. Ultimately our porselain replicas will be sold in an museum store in Delft and possibly in the museum store of the Boijmans Van Beuningen Museum. More about this when this actually happens. 🙂

 

Finally, we like to thank everyone for reading our blog and also thank those who attended at the science fair. We also like to thank those that helped us with the many obstacles we encountered. We had an awesome time doing this kind of research and are happy to take another important step in the world of Augmented Prototyping. We will keep this blog updated when there are more developments.

 

As a bonus, some photo’s that were taken during the science fair. Enjoy! 

 

 

 
 

 
 

 

 

Science Fair! (26-10-10)

The results of this project and other projects will be shown at the Science Fair coming tuesday.
Everyone that is interested, is more than welcome to come and visit us!
 
 
 
 
DATE AND TIME
26-10-2010 
14:00 – 17:00
 
ADDRESS
Science Centre TU Delft
Mijnbouwstraat 120
 
TRAVELLING PLAN
Science Centre (in Dutch)
Google Maps 
 
SPECIAL APPEARANCE
At 16:00 there will be a special presentation
Concerning Forensic Visualisation
By the project manager of the RRD (crime scene investigation)
 
FEE
Youth: 4,00 
Adults: 6,50
Students and TU Delft Employees: Free
Museum Card: Free
 
 

 

Casting the Molds

Last week’s Thursday (21-10-10) we went to Maaike Roozenburg’s Studio in Koog Bloemwijk near Amsterdam. At 9 am we also picked up the synthetic polymer prints. These turned out to be printed very well, but every one of them is too fragile to be used for mold casting. We now have a total of 12 printed glasses.

 

 

 
 
 
 
After discussing which glasses we will make molds of today, Maaike teached us the basis principles of mold casting. Because the molds consist out of three parts, one side of a glass and the top and bottom of the glass are covered with clay. After this the 4 sides of the clay are clamped with wooden formwork. Then the plaster solution is carefully poured into the mold. This has to dry and harden for about 30-45 minutes. Next, the mold is put upside down to cast the other side and finally the bottom.
 
 
 
 
 
 
 
Because this is a very time and labour intensive process we did not manage to finish the molds. Also, they have to dry for a couple of days before they can be used. Maaike will finish the molds that we did not complete. All in all, we learned a lot today about mold casting. It is not as easy as it seems!
 
 
 

Reinforcing the Powder Prints

Today we reinforced the four powder prints with candle wax. Not without problems. One of the glasses collapsed under its own weight when it absorbed the wax. Luckily, we still have the polymer prints. The molds will be cast next thursday.

 

 
 
 
 
 

 

 

Quick Update

A quick update to let you all know we are now waiting for our 3D models to be printed. This did not come easy. After we scanned and processed the glasses from the Boijmans van Beuningen museum, a lot of problems occured with preparing the files for printing. With plenty of hard work and the knowledge Dr. Y. Song provided us with, we tackled most of these problems. This resulted in 2 out of 4 models from the collection that can be printed. The problem with the remaining two glasses is that they had too many holes in them. Holes are very labour intensive to repair when using meshes. We decided to use two of the three glasses we scanned from the Delft Historical Archive, so we have four printable glasses in total.

 

As an experiment we are also printing these four glasses in low resolution. The surface of the exterior of the glasses will give the impression that it is made from layers, like in the scan. This could result into a interesting aesthetic factor. As a second experiment we are using 3 types of 3D printers to observe their accuracy, material properties, cost and other factors. The four high resolution glasses will be printed with both the flour printer and the polymer printer. The four low resoltion versions will be printed with a synthetic polymer printer. If everything goes well we will have 12 printed full scale glasses by monday.

 

Below are the renders of the glasses that will be printed in both high and low resolution. Glass 2 and 4 are from the Boijmans Van Beuningen collection. Glass 494 and 553 are from the Historical Archive.

 

Glas 2 – high

 

Glas 2 – low

 

Glas 4 – high

 
 

Glas 4 – low

 

Glas 494 – high

 

Glas 494 – low

 

 Glas 553 – high

 

Glas 553 – low

Meshing Madness

After yesterday’s scans the next step was to convert these files to printable STL files. Therefore, we used an applications that could convert these files for us. After a lot of trial and error that we experienced over the weekend, this was done in much less time. Viewable three dimensional files were produced very quickly. Because we used the medical CT-scanner (the one with a lesser resolution) the result was slightly dissapointing. But the recieved files were a lot smaller (say, ten times smaller) and can be processed much easier.  We even managed to smoothen the surface, so it doesn’t not look like the previous test glass. This was done by first exporting the files to a different extension then STL, and then loading it into Rhinoceros 4. The results of the scans and the converting process, which we are very satisfied with, are shown below.

 

 

After some tweaking and editing it was time to finally export the file to STL. To our dissapointment the result after exporting was very unsatisfying. The now printable glass looked nothing like the original shape. The surface was distorted and edgy. This was not how we imagined how the printed glass would look. After consulting with the 3D printer opperator, he confirmed the print would definately look like what we saw in the modelviewer. This is how the glass would look if we didn’t do something to improve it.

 

 
 
Because what we are attempting is not done before very often, there are not many people that could assist us in this matter. This resulted in again many hours of trial and error. Ing. A. de smit (our Rhinoceros expert) explained us that what we saw in the rendered image was not the real thing, but an interpretation that Rhinoceros made for a better looking render. After almost haven given up, we contacted Dr. Y. Song. With his broad knowledge about situations like this one, he managed to ‘repair’ the file and produced an amazing looking printable three dimensional copy of our glass. From which the result is shown below.
 
 
 
 
We are very happy with this result and will 3D-print this glass in plastic for further testing. The result will follow tomorrow.

We’ve done it.

It worked. After even more hours finding out how to combine the slices of de scanned model, after countless more computer crashes, we finally managed to load the entire model into Rhinoceros 4. We now know that when we scan the real 17th century glass we can definately convert it into a printable three dimensional file. What is left now is the process of making the model of the glass into a mold. This is not done by simply turning the object into it’s negative. Figuring out how this will work, is our next task. Again the result of our work is shown below. It is a render made with Rhinoceros 4 from the scanned test glass.

 

 

DICOM to STL Breakthrough!

After spending many hours on the internet, we finally managed to convert some of the data of the scanned test glass. The scan of the glass (that was done by the smaller Nanoton) has produced several slices. Because of the high resolution and high accuracy of the scanner it overwhelmed us with well over 1000 slices, resulting in a 3GB DICOM file. Converting this data to a 3D-printer extension (like STL) is not as simple as it sounds. The slices are horizontal scans, pictures you might say, made every fraction of a millimeter. These pictures do not contain any data that represent a coordinate system. Therefore, boundary edges for every slice have to be made and a computer program that can combine these edges has to be used. When this has been done, this program will combine every boundary edge and shape them into the final model. This model (now consisting out of points rather than image data) can be exported in STL format. This can be loaded into a modeling application, like Rhinoceros 4. Again, this is more difficult as it sounds. The 3GB of data, or 1152 slices, is too much for a home pc to handle. Therefore, sections of maybe a 100 slices at a time have to be made. Yesterday, as a test, we managed to successfully convert one single slice into a STL file and loaded this Rhinoceros 4. The result is shown below. Our next step is to try and combine a set number of segments into a complete model.

 

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