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2. Digital bodies

Machine_Hand_Made

Motivation & previous work

motivation
First Row: Images of some aspects of ergonimcs for some musical instruments. Second Row: Three different versions of the "Percutarra" (An instrument for playing drums on a portable object)

I've been involved in the scenic fields with music, theater and circus plays. So apart of playing there, as fabber, I've could played in the design of instruments, props and scenographic objects for some projects.

So, for this class, my main interest is in the fields of anthropometry and ergonomics, specifically when playing an instrument or doing an scenic play, using typical fab lab resources.

I want to add that this reason and the whole process wasn't very clear at first, it was feed back and forward with the exploration of tools, and ideas.

3D Scanning

scanning
First and second columns: Body Selfie Scanning process with Kinect (XBox 360) Hardware and with ReconstructMe and Skanect Software respectively. Third Column: 3D Model Visualization

I had played before during some periods with the use of kinect with a diversity of tools, including, skanect, reconstruct me, kinect for windows tools, and even the SARndBox project.

But, in each time, I always have a sensation of haven't explored the whole potential of the tool, because sometimes I can't play with illumination, positions, processors, or having time and resources for that.

I have to say that now the model of my kinect and also skanect is deprecated, but time ago I made some research for getting the right drivers, and tools in general for continue working with them in OS fresh versions.

It is possible to use the scanner the same person, because the two programas I used have a time counter option for starting the scanning.

It is important to have a right computer, with a dedicated video card. I have noted before the difference when the process starts, it can start to lost the tracking and reconstructing images during real-time, causing, incomplete or deformed scanning results.

So for this week I started making a 3D selfie for now, and also doing some explorations with smaller objects, like my hands.

My first conclusion insight was that the 360 rotation of the arm when is being scanned, is dificult without obstructing the view of the kinect. Now I'm thinkig that maybe I can try different position for the kinect so I can achieve the complete rotation of the arm.

Second, I think there are some parameters with the algorithm construction of the object, dependeing of the size object, because the distances are smaller and also it has to have a diferent set-up, maybe unaccesible for programs like skanect.

Finally, since this is not a very new technology and was designed with other purposes, it can be limited to certain size of objects and processor capacities.

Transforming, Searching, Slicing

scanning

With scanning processes there is another issue: the size of the file. I have to say that when I tried to work with my scan in meshmixer, the computer went very slow. Maybe there are some simplifications processes, but for now I decided take a new way and try to looking for a hand model in the sketchfab platform since I haven't tried too much before.

I find a lot of 3D models there, and even a nice collection of hand models. I choose a one hand model and start working faster with it in the next processes.

For the slicing process, I want to remark that is very important to put attention in all the slicing parameters and messages, including:

  • The area and broad of your material
  • The warnings of the program
  • The review of the total number of sheets (you don't have infinite material and time for cutting)

I didn't do it, but I think is desirable make a test for the assembling tolerance, Slicer has a tolerance option. But I recommend always test this with a small sample, because also each machine can need differente specifications.

Manufacturing

scanning
From left to right: Vector visualization with built-in camera. Laser position and tracing order when cutting. Final result

This is a familiar process for me, I just would like to remark that the export/import of the files was right and easy (Using the .dxf format), I didn't had to transform any vector also, I just had to ungroup and manually select the vectors for cutting and letting the other vectors in scoring.

It works for around 30 minutes each page of 30x30cm

Preparation for laser cutting

CAM Software for Xtool M1 laser machine
  1. Load / Update machine connection
  2. Load vector or raster image
  3. Traditional and advanced CAD tools and working area
  4. CAM tools (With easy working mode with material presets)
  5. Framing and working buttons

For this project, my material settigs were:

  • Type: Medium desnsity fiber (MDF)
  • Thickness: 3 mm

My machine settings for cutting were:

  • Power: 100 %
  • Velocity: 3 mm/s
  • Passes: 1

The software has preseted parameters by choosing materials from his database. In this perspective, I choosed 3mm pine plywood, beacuse ther isn't MDF on the database.

The resumeed machine characteristics are:

  • Laser output power: 5W
  • Maximum laser cutting capacity (under laboratory conditions): 3mm Basswood board
  • Working area: 385 * 300Mm (laser working); 365 * 300mm (knife cutting)

Assembling

As you can see in the video, Slicer gives you also an step-by-step assembly instructions, so even this design is easey to assemby, in some shapes it can be tricky.

At the end, the assembly finished a litle weak, I would liked to try a small assmebly test first, thats why I said before. But wih the whole parts it finished stronger.

Also, even I didn't get warnings in the slicing process, at the end, some pieces were very small with small or inexistent slots. I think is important try to know well your model, and considering that the human body has organic shapes that can be a true slicing and manufacturing challenge.

Remarcable Tools

3D Scanning

  • Kinect Sensor Xbox 360 Modelo 1473 (Deprecated)
  • Reconstruct me
  • Skanect (Deprecated)

3D Viewing and Editing

  • Microsoft 3D Builder (Free and available en MS Store)
  • Microsoft Visor 3D (Free and available en MS Store)
  • Meshmixer

3D Objects Library

Manufacturing

Documenting

Fabrication files

  1. File: Laser cut sheets ↩