3D Scanning and Printing

Softwares Used

Scanning

I already had an object I wanted to make this week, as you can see from my Final Project page, when I visited Rachel Freire's workshop in London she had some 3D printed hands on which she was safely storing and displaying gloves. I wanted to make some of these for my own designs so that I could take documentation photos of my gloves in a better way than just laying them on the table. At the start of this week Julia, the actress who is going to be working with me to test my designs was visiting in order to become more familiar with Mi.mu's Glover software. I decided to take a 3D scan of her hand so that the model would accurately fit a pair of gloves made for someone her size. I scanned her hand using a Structure scanner and Ipad pro, this then gave me a .obj mesh file that I emailed to myself to begin editing. When scanning you have to make sure you are in a clear area where no external objects will be picked up and that you move in full 360 degrees around each direction of the object being scanned. You will know it is finihsed when the whole item is filled gray on the camera screen of the app. The file did include a large portion of chair, which we had used to rest Julia's arm on, This would have to be removed afterwards as support was needed in order to get an accurate scan of the fingers.

Ipad with Structure scanner attached.

Preview of my scan given by the Structure app.

The app also generates a .jpg file containing images ofevery angle of the object scanned, which is a nice feature in terms of aesthetics.

Editing the scan

To edit the file from the scanner I imported it into Autodesk's Meshmixer. In the software I used the select tool to select the large portion of the scan that I didn't need and then removed that. This left me with the portion that I wanted to print. I then filled some holes in the mesh, left by the scan using the shrink/smooth tool found in the sclupt menu. After this I selected the model and used the fix cracks tool, in order to smooth over any gaps left by the scan in the portion that I wanted to print. My next step was to make this a solid using the settings shown below. I still needed to make my model into different parts to allow the glove to be put on easily and for it to fit into the 3D printer. First I reid to do this using the select tool, however this didn't work as the tool selects the geodesic triangles of the mesh, not in straight lines. I then found and used the plane cut tool, found in the edit menu to cut my solid model into pieces that would fit into the Makerbot 2X printer that I was going to print on. Slicing into different parts will also make it easier to get the gloves onto the model hands after they are finished. Before slicing I copied the hand solid in the same position 3 more times. This is because, in order to form a new object using plane cut, you must delete the portion to be cut away. I made more copies in order to create four portions that could be sliced as I needed. I intend to attach each slice to the other by drilling holes and inserting magnets into the joins. I did try doing the slicing in Fusion 360, as the I am more familiar with it than Meshmixer, however it's tools aren't optimised for workiing with mesh type files and I ended up going back to Meshmixer for editing after trying to make Fusion work. After persevering with the software I found the learning curve not to be too steep, even though I wasn't initially a fan of the user interface. It turned out to be a much better tool for editing a mesh in this way than Fusion. After slicing I exported all of my objects as .stl files.

After importing the file into Meshmixer it looked like this.

This is the portion I will print, shown after the chair back was removed, but it still has holes.

This is what the model looked like after the cracks were filled and I used the shrink/smooth tool to fix the holes near the bottom of the mesh

The sculpt menu, showing the settings I was using to edit the mesh. Shown as it can be confusing knowing which brush tool to use for which purpose.

Another reason I attempted to use Fusion 360 for slicing the hand was that Meshmixer seems to be unstable and kept crashing. However, as I said above, the process in Meshmixer was far easier. Therefore all the images below are still from my work in Meshmixer.

Trying to segment the hand using the select tool, as you can see, this gave a jagged rather than straight edge. In order to get a straight edge I had to make the hand a solid and then use the plane slice tool to slice off each part I needed.

The settings I used when making the hand into a solid.

Copied objects shown and named in the Object Browser.

Using plane cut to slice the hand, it is important to make sure that the cut is being made only through elements you want to be separated, at the correct angle on each axis.

The hand after cutting. Each colour represents a separate portion of the hand.

Preparing for Printing

After scanning I needed to find the correct software for the printer I was using. MakerBot's most recent software, MakerBot Print, was not compatable with our printer as they o longer support the Replicator 2X. This means that when I went o use the software all I was given was a blank screen. I then had to search for earlier versions of their software that still supported the printer. I found MakerBot Desktop which worked and supported the printer. It is MakerBot's recommended software for this specific printer as it is the last iteration that supports it. In this software I prepped my .stl files for printing. When opening the software the first thing to do was to set the printer to the one I am was using in the settings. This automatically set the print bed size within the software. I then edited the settings for the print to include a raft and automatically generated supports. I also set the print material, mine was abs, the software preloaded the correct temperatures for printing with this material. I set these for each of my parts, making sure not to resize any of them.

The .stl file imported into MakerBot Desktop, after this I angled it and plaed it so that the flat side was on the bed, minimising the number of supports that would be needed.

The print preview of my first piece, containing raft and supports.

A short video of how the printer prints, showing the hexagonal mesh it uses to print the inside of objects (this can be set to other patterns, but the hexagon is the makerbot default and good for structural integrity).

The printed piece, including raft and supports. The top finger is a slightly different colour as I had to change the filament halfway through.

The piece with raft and supports removed. As I was doing this the piece split along the line of the filament cange. I just used a hot glue gun to stick it back together.

I tried printing the second piece without a raft so I didn't have to remove it after, as this proved difficult. The piece warped and didn't stick to the bed so I had to continue using rafts to print my different parts.