2. Digital bodies#

This week I worked on making my own mannequin from a 3D scan of my own body.

The following is the a picture of the final product:

Cost of materials: $27/sheet
Total number of sheets used: 3
Total cost: $81

Research#

3D scanning of body#

3D scanning was performed with a portable 3D scanner made by Ametek. The scanner is connected to a computer and uses a piece of software called VX Elements. The software collects scans based on these stickers you place on your body. It’s recommended you place the stickers in a random order.

Scanning my body was challenging. To scan, you must calibrate the scanner on a flat surface provided by the company. Then you calibrate the distance at which the scanner can collect a good scan on the actual object you are analyzing. First, I was scanned (thanks, Oye and Eamon!) while standing in the middle of the room. A bunch of yucky scans were collected with the software that were unusable when it came time for cleaning up the model. The most successful trial for scanning involved scanning my front side and back side individually while lying on the floor. We think this was most sucessful for the scanner because it needed a stable surface for the lasers to reflect from (apparently I couldn’t sit still enough)

The final scan collected and stitched by the software can be seen below. There was a lot of work to do in terms of clean-up!

Repairing of 3D model#

After exporting an stl of my front and back sides, it was time to get to work. This part took a little longer because I was not as familiar with Meshmixer, but after many frustrations – I feel much more comfortable with it now! :). Here are some general steps I took to repairing my 3D scan:

Digital tummy tuck - the VX Elements software made me more pear-shaped than I am, so I had to adjust the bottom part of the mannequin. (I didn’t hold my breath for nothing!) To do this, I took the .stl, separated it into two objects (front and back), transformed the front side by rotating it to the right angle.
Stitching together islands of the 3D scan - I used Bridging and Erase & Fill copiously to try to made one continuous .stl. One thing I found was that scanning my front side was more problematic than scanning my backside - I found multiple layers with the front scan of my body, maybe because I was breathing a lot and the scanner was constructed multiple layers in the 3D model.
Creating a base and adding stubs for arms - I used existing Meshmixer Primitives - a cone for the base and arms for where my arms should go
Final clean-up and cutting off arms - Making sure everything was a continuous volume, I used Edit > Inspect to fix holes, Sculpt to smooth out wrinkles, and Edit > Make solid to smooth everything out. I’m sure I could have just used the Make solid option to clean up everything in one shot, but I was still learning.

Creating slices of 3D model#

I imported the cleaned-up stl file into Slicer for Fusion 360. In the program, I specified the material dimensions (36” x 24” sheet, 0.25” [6mm] thick acrylic) that I was going to use for assembling my mannequin. As I played around with the construction methods to make the mannequin, I ultimately honed in on the interlocked slices method because I wanted to use the least number of acrylic sheets. Since I was using this construction method, Montserra suggested to add tolerance for thickness of the sheet to make assembling the slices easy to do. Thus, I specified a thickness of 6.1mm. This generated a total of 4 acrylic sheets to use. I ended up moving the few pieces that were on the fourth sheet to the third sheet, so technically I used a total of three sheets to minimize waste

To prepare for laser cutting, I:

Exported the file as a PDF,
Imported the PDF into Adobe Illustrator (AI), cleaned up the numbers and modified cut lines so the laser cutter could recognize the paths, and
Sent the prepared AI file to the laser cutting software

Lasercutting slices#

Lasercutting the acrylic sheets was pretty straight forward. I generated two defects from the whole cutting process (there was a weak spot in one of the sheets)

Assembling 3D model#

After successfully laser cutting all pieces, I assembled all the pieces by hand (with help from Jillian Friot at Dassault and a little permanent glue). Here were the steps: