3D Scanning and Printing
scanning
This week I have been tinking with a couple of scan models. A manual 3D system Sense scan which I used to scan myshelf and a Makerbot tabletop scan that I used to acquire some 3D models. I always have been interested about the relationship between phisical and digital models. Since I was a child I like to model small pieces using modelling paste. I discovered Zbrush that is the most similar way to model in the same way you can do with a modelling paste ball.
So, you can model whatever you could imagine either in a manual or digital way. If you model a phisical model you can scan it and you get a digital model in the same way you can model it directly.
Nowadays whitin the Architecture there are some development ways we can see this kind of concept. For instance, if we focus on Frank Gerhy’s works the translation from physical environment to digital model it is produced through the use of a scan.
3D printing
I usually print with a Prusa i3 using PLA and ABS commonly. I prefer ABS because this kind of material offers a better mechanical behaviour if you are printing joints, knots or these a kind of pieces which should have a bit of mechanical strengh besides it is possible to apply post-production proccesses in order to improve the finishing aspect of the material, as you can see bellow.
Printing parameters I use are 200-210/60-70 for PLA and 220-230/90 for ABS. As slicer software I usually do it with CURA.
I did not find special problems regardless of those related with the refining of the mesh obtained from the scanning procces. Actually I got a coarse mesh when I scanned my physical model and I had to spend a great amount of time refining it using Zbrush in order to obtain a model appropriate enough.
One thing you have to bear in mind is the extremely high number of triangles that compose the mesh if you are using Zbrush. It reflects in a very heavy archive that is not useful only to print it. So simplify the mesh should be a good idea in order to get a well balanced archive if you only are thinking on printing the model and should be better if you want to share it as well.
Scanning myshelf using a 3D system Sense scan.
How the scanning system signs a bridge from physical model to digital one and how an almost physical model would be produced using some kind of sotware as Zbrush.
The model I made up is a very good example about what kind of things you should try to print rather than fabricate it using substractive methods. Probably the trials might be interesting enough but if you want to get an accurate result the difference is clear.
Download pencil_head_bat LOW RES
From digital model to physical one. Using Zbrush to model a sketch. Refining the mesh in Rhino a low weight archive should be obtained. It has no impact on the gcode that you get in order to print it.
Post-production procceses as acetone vapour bath offers amazing results depending on the kind of working you are doing. Take care with the quantity of time you apply to your piece. A rag or piece of paper wetted with acetone closed with the piece into a glass flask allows to see the proccess and so you can control the point of smoothness on the piece.
Using a physical model, the proccess is quite different although the concept is the same.
Refining the mesh obtained using the scan could be quite hard, something like smoothing the material.
I worked on the physical model printing on the Formlabs printer. I usually work with shelf-constructed printers that requires a lot of fittings and adjusments so the proccess in this way was very easy and the finished model was fulfilling.
Finally I have to say that the overweighted files of the models, although they were lowered quite enough by simplifying the mesh, do not allow to upload them as attached files directly on this web site. So I hosted them on SketchFab which is a nice site where 3D modelers uses to hang many amazing works.
