CD3D decided to perform an experiment and persuaded Michalina and Adela (myself), two girls who deal with 3D printing on a daily basis, to swap places. What was the catch? Michalina works with a professional machine Objet Eden 350, and I use low budget 3D printers. What are our impressions from the swap?
Michalina works at the Laboratory of Individual Medical Implants in the Łódź Technopark. The Lab uses Objet Eden 350 for printing anatomical models which help doctors plan surgical operations or adjust implants for a particular patient’s body. In theory, Michalina was familiar with the principles of operation of the FDM 3D printers, but until then she had never worked on such equipment.
I am a member of the CD3D team, and I deal with printing on low-cost 3D printers every day – mainly on Zortrax and Monkeyfab PRIME. I print virtually anything that people come up with: technical parts, cookie cutters, jaws, figurines, key chains… I had seen the Objet professional printers at the university, but I never operated them personally.
Our task was to print models typical of our everyday projects, but by means of 3D printers completely different from those we normally would use. Thus, Michalina went on to print an anatomical model of an eye socket on Monkeyfab PRIME, and I would use Objet Eden 350 to print a model of the 3DBenchy boat, which we often use at CD3D to test 3D printers and filaments.
The first task that Michalina had to face, was to change the filament. From the first moment she moved smoothly through the menu in the 3D printer control panel, and quickly found the option that slid filament out of the extruder. It took her a while to find out which way the new roll should be placed, but the installation itself took just a few seconds. With the grace appropriate for the Monkeyfab equipment, the filament got jammed in the section right before the hotend. A rescue mission with a pair of tweezers was necessary at this point. Finally Michalina managed to extrude several centimeters of plastic without any more problems.
This is not the end of the initial challenges, as Kisslicer was waiting just around the corner. Kisslicer is the program recommended for use with the Monkeyfab PRIME printer. Michalina quickly managed to load the model of the eye socket into the program. And there the success story ends. The next step – rotating the model in order to set it in the best position for printing – proved to be impossible. After a few minutes of helpless attempts and struggling with the overwhelmingly unintuitive Kisslicer’s interface, I decided to grant Michalina a handicap and I suggested she used Cura.
The program was definitely more to Michalina’s taste, as the interface to manipulate the model on the work plate reminded her of those she was familiar with in the programs she used at work. Very quickly she managed to orientate the model the way she chose (a most reasonable one in fact). The next step was to select the print parameters. The layer height and travel speed parameters sounded familiar, the rest – not so much. At this point, of course, Michalina needed some hints, since it would be difficult to find out what should be set and on what level. Once the parameters were chosen she only needed to generate the g-code and upload it to the 3D printer.
And there came another surprise – Michalina assumed that the code is loaded onto the 3D printer directly from Cura. Unfortunately, it turned out that it had to be loaded onto an SD card, which then needed to be plugged into the device. At the start of printing Michalina also wanted to cut the work short and pressed the “PLAY” button on the control panel instead of choosing this option and the g-code from the menu. After the start of printing she demonstrated good efficiency with an Allen wrench and made a necessary adjustment of the plate’s angle. She admitted, however, that Monkeyfab, compared to Objet, requires a huge amount of work with initializing prints.
After an hour the printout was ready and Michalina was handed a spatula. Initially, she did not know how much force she should use to detach the printout, but she soon realized that delicate pecking will not do. A few decisive moves and the printout was separated from the glass. Michalina politely mentioned that the material in her machine is much more cooperative when it comes to removing the prints from the plate. Only the best stuff was left – removing the supports off the model, which had numerous irregular cavities (“paranasal sinuses”, Michalina expertly explained).
Removing the supports was time-consuming, but the patient Michalina cut them out very carefully. ” It wasn’t so bad” – she concluded, though emphasized that cleaning the sinuses was very difficult. In her view, the printout did not look bad, but she did not see the FDM technology 3D printers in her work, due to the fact that the filaments are not certified for medical applications. Models printed in the FDM technology could only be used for demonstration.
Contrary to my worries, the Objet 3D printer software turned out to be rather uncomplicated and, in fact, there was very little to be done with it. It was enough to load a model, scale it, place on the plate and read the material consumption – these were all the actions that had to be done in the Objet Studio. I could find the options I needed in the program rather intuitively.
However, at the request of my work’s supervisors – Michalina and dr Marcin Elgalal “now you need to put the model in the right spot on the plate” I instinctively moved it to the middle of the plate, like I would do on my 3D printer. It turned out to be a mistake, as in this case I should have chosen the “automatic placement” option, which places the printout in the corner nearest to the printhead’s resting position – this arrangement of the model ensures an optimal movement path of the head.
Once the “tray” with the printout was prepared I only needed to move to the other computer, embedded in the 3D printer, and initialize printing, followed by observing as the head slowly heated up to the required temperature. After a few minutes Objet started printing. There was nothing to look at, though. Both resins – for the supports and for the model – are transparent. Objet is a device that does not require much attention from the user, a machine that works for man (as opposed to the Prime, where one may get the impression that is the man who works for the machine, bending over backwards to get the best printout in spite of all adversity).
The printing was supposed take two hours and 12 minutes, in fact, it was much longer – 2 hours and 40 minutes. When the process was finished, Michalina gave me two (!) spatulas. I was equally unaware, like Michalina was with Monkeyfab, what to expect when removing the print from the plate. I tentatively held one of the spatulas and… it turned out that the blade went between the printout and the table like a knife through butter.
The last step was to rinse the support material, which is removed with a stream of water in the glovebox. And there came the surprise – it was not an easy and quick operation at all. It is difficult to hold a small model, showered with a strong jet, with a hand wearing a huge glove. After a long rinse there still were some remnants of the support material on the boat. Cleaning the model takes at least as much time as removing the supports printed on Monkeyfab. But the boat made with Objet looks like a little better than the one from the PRIME…
The 3D Benchy boat printed on Objet Eden 350 took 2 hours and 40 minutes to complete and consumed 25 grams of resin and 28 grams of the support material. The cost of the ncessary materials was about 250 zł (59 EUR)
The same boat on the low-budget Monkeyfab PRIME printer takes about 40 minutes and consumes 7 grams of plastic. With filament at a price of 100 zł/kg (24 EUR/kg) , the cost of the material for the model was 0.70 zł (16 euro cents).