It was on 7th July, 2013, during the first edition of the of the 3D printing Day in Kielce when I saw it – the head of Pawel Twardo of Monkeyfab, printed from red PLA in 1:1 scale. From the very beginning the printout was a huge sensation and became one of the most photographed models from a 3D printer in Poland. Whenever somewhere in Poland there is an event and Monkeyfab is there, you can expect to see pictures of Pawel’s red head in the event’s reports. The printout is very good, in fact it is brilliant in its simplicity. After all – it’s just head… Some time ago I started to wonder if it is possible to do something even better, go a step further… The answer occurred to me fairly quickly – perhaps I could do exactly the same thing, but in color…?
Before we move on any further, I would like to emphasize that our project was absolutely not designed to compete with Monkeyfab’s project, with whom we have excellent rapport. We too just wanted to have a printed head to show at events and training courses, and we understood that Paweł could have perfectly justified objections to sharing his own head with us for the marketing, educational and entertainment purposes. 🙂
To collaborate on the project, we invited Mariusz Szymbor of the DIM-CAD company, Arek Śpiewak from 3D Printers and Piotrek Danielewicz of Galaxy Kits. The person who helped us and lent us a head was our sincere friend Ewa Leszczyńska, with whom I had the privilege of working at an IT company, for which we carried out a number of online projects together. DIM-CAD was responsible for the 3D scan of the head, 3D Printers for its print in the FDM technology, and the Galaxy Kits for its painting. Here’s how the project was done…
3D scanning of a person’s head consists of two stages: the face scan and the hair scan. The first stage is simple, easy and fun and takes takes relatively little time. Some pretty decent results can be achieved even with simple and cheap devices, like Sense or Kinect. The second stage, that is the 3D scanning of the hair is one of the worst things you can commission from a company offering professional services of this type… Usually the scanned hair is tied closely at the back of the head and is placed smoothly on the skull. It is also better if it is as bright as possible, because in the case of darker colors there is a problem with correct mapping of the hair by the 3D scanner. We decided to max the difficulty level, as our model’s hair was loose and raven black…
The 3D scan took a long time, nearly two hours. While the 3D face scan was completed relatively quickly, the attempts to recreate and put together Ewa’s hair in real time were tedious and laborious. We used some high-class equipment for the 3D scan, namely: HDI Advance R3X – white light optical 3D scanner, with a resolution of 2.8 megapixels. Although in the case the face we achieved incredible accuracy and mapping quality (we kept joking that on the basis of the 3D scan we were able to recognize the mascara brand), in the case of the loose black hair there were problems with their proper modeling. Nevertheless, we managed to achieve satisfactory quality.
Unfortunately, in the process of analyzing of the resulting STL files for the purpose of 3D printing in the FDM technology, after long discussions we decided that… the printout would not work out well. We were worried that the number of supports which would be generated to print the hair – in particular the fragments where the hair touches the bottom part of the face, near the neck, would be printed in such a way that subsequent processing would be very troublesome and might deteriorate the printout’s quality. Therefore, despite the fact that the 3D scan went well, we made the difficult decision to repeat the whole process.
The second time around, Ewa had already carefully pinned up her hair and we stopped focusing on this element so much. We already knew that the FDM technology would not allow us to recreate the hair to such an extent as the 3D scan in HD would, so we did it quickly, although thoroughly. As a result, this time the 3D scanning took only a few minutes instead of two hours. Ewa’s face was once again reproduced in a digital form with hyper-accuracy – based on the scan we were even able to count the eyelashes 🙂
Since the head was to be reproduced in 1:1 scale we needed a 3D printer which was able to print models which measured approximately 30 cm in the Z-axis. The only device with such capability which was available on the market was the HBOT 3D by Arek Śpiewak of the 3D Printers, which had a build area of 30 x 30 x 30 cm.
In order to be able to print such a big and unique object, the STL file had to be appropriately modified. First of all, a fragment of the torso was removed, leaving only the head and the neck. Next, special supports were designed, which, on one hand, ensured the printing quality, and on the other, allowed for an easy and painless removal. The hardest part of 3D printing a head is the chin. Unfortunately, 3D printing in the FDM technology makes this element always less appealing because of the bull’s-eyes and the visible strands of plastic. Most programs (both open-source and proprietary) set the default supports in such a way that the end result is rather undesirable. Arek and his team designed the supports in such a way as to completely overcome this problem.
The 3D printing took about 30 hours. The printing of supports lasted the longest. The printout itself was empty inside – to maximize the speed of the work. The layer height was also relatively big, at the level of 0.2 mm – going down to 0.1 mm would considerably prolong the printing time. The printout was made of gray PLA, dedicated for the HBOT 3D printers.
Post-production and painting
We handed the printed model over to our colleague – Piotr Danielewicz, a very well known person in the modeling industry, the creator of the Galaxy Kits website, with whom we had already cooperated on several projects presented in CD3D. The printout underwent a standard modeling processing – some fragments were polished, then covered with a layer of modeling putty, which was later polished again. Then, several layers of primer were applied and the final painting began.
The last stage was to put… traditional make-up on some fragments of the model and add a few accessories 🙂
Scanning and 3D printing of people’s heads is both a spectacular and exciting task. It is also quite problematic and requires specific knowledge and experience. Today, in hindsight, we know that the project did not require such an advanced tool as the HDI 3D scanner, as the accuracy with which it reproduced Ewa’s digital model was too high for the capabilities of the FDM technology. In order to be able reproduce it with all the details, a different technology, at least the SLS, should be used, which in turn would entail huge costs. On the other hand, comparing with the 3D Sense scanner, the difference in the models’ quality is staggering.