Hippos: My Introduction to the World of 3D Scanning
A few years ago, my Dad brought home a carving of a hippo made by a friend's ranch-hand in Zimbabwe. The little guy has since lived on my desk, far away from the African climate that he was accustomed to. One day it struck me that he must have been lonely, with no other hippos to keep him company. I wanted to get him a twin hippo, but carving was not an option for me... I don't think he'd recognize the result! Instead, I decided to use my newly-acquired NextEngine 3D scanning system (snagged used from eBay) and a 3D printer.
The scanning process turned out to be anything but easy... as you can see from the image below, each individual scan yielded very little usable information. After countless hours of troubleshooting, scanning, and adjusting, I learned several things:
- The little zero-backlash gear drive system within the scanner needed lubrication. This was responsible for several pesky artifacts.
- Powdering the hippo with some baby powder or matte makeup helped the scanning process out significantly. Materials that are too dark or highly reflective do not tend to scan well; the buffed hardwood hippo was both dark and reflective.
- It's all about patience. Getting scans from as many angles as possible is helpful. By the time the process was done, I had collected some 1.5Gbs of scan data!
The result, arrived at after a week or so of tedious work, was glorious. Note that, even after the scan looked good within the scanning software package, it required additional work to make the STL watertight. Doing so, as I learned, was the first step in creating a solid model that could be imported to a CAD program like Solidworks, which I then used to make the model hollow so that it could be printed by a service such as Shapeways more inexpensively.
TO BE CONTINUED...
Finally, the time came to create hippos to keep my original friend company. My first print was produced by Shapeways at 100% scaling in their "alumide" material, which I think is a nylon and aluminum blend, fused into its final form using an SLS process. That model turned out great.
My second hippo was produced at home, on my very own 3D printer (at the time a modified BFB 3D Touch) out of PLA. Once it was done, I carefully sanded it and filled in any low spots with a wood-filler. I sent the finished model to a local foundry, where they performed a lost-wax (really lost-PLA) process. The result was my very own solid bronze hippo, weighing in at a whopping 15lbs!