A few months ago I upgraded my cell phone to the Galaxy S3. It's a great phone. One of my favorite features is it's ability to create panoramic pictures. However, I noticed that sometimes the pictures didn't quite line up right. After talking to my brother-in-law about this I found out that the best panoramic pictures are created when the camera is rotated on it's axis. Perfect, this sounds like an opportunity for me to make a fixture! I've also been looking for a project to use 3D printing, so I think this will be a good opportunity to try it out.
Step 1: Find a CAD Model of the Samsung Galaxy S3
The first step is to acquire a model of your phone. You can, of course, model it yourself in your favorite CAD software. However, there is a pretty good chance someone has already created a model if you have a popular phone. I found a nice model of the S3 on the GrabCAD website.
Step 2: Start Designing
It's time to import the model of the phone to your CAD software and start designing. I used Solidworks, but there are many other products out there such as FreeCAD, AutoCAD 123D, Google Sketchup, and Blender just to name a few.
I'll apologize right now for the vagueness of this step. It is time to let your creativity flow!
The goal of my design was to hold the phone in a stable position while allowing it to rotate around a vertical axis that goes through the camera. I also wanted to be able to mount it on a tri-pod in addition to being using it on a tabletop.
Since this was my first 3D printing project I wanted to have a little fun and incorporate some of the freedom of design that you are given with 3D printing. I typically design machine parts that are milled on a CNC and have to obey the design laws that go along with that method of manufacturing.
Step 3: Iterate.....many Times
After many iterations my final design came out very different than my original ideas. The biggest lesson I learned is this: If you are going to have a part 3D printed you need to minimize the amount of material needed to create your part. The volume of a part will add up quickly and that is how your part is priced when it is quoted for 3D printing. So, I thinned out my original design by hollowing/shelling areas that didn't need a solid cross section and just cutting out areas of material wherever possible as seen in the picture of the final design.
Step 4: Make It!
After looking at a couple different online 3d printing services I decided to send my model to Shapeways for printing. It was pretty simple. After you sign up for an account you can upload your models (in STL format), choose your material and place an order. It takes a couple days before they fully verify your model and about 1 week to print and ship.
I chose to make my model out of the white strong and flexible nylon, which is laser sintered. I was impressed with the surface finish of the parts. They are slightly textured, but I was expecting the layers to be more noticeable.
I immediately noticed that I made the walls of the phone holder portion too thin. I guess I'll need to add some more support structure for the next revision.
Step 5: Some Assembly Required
I bought (3) 1/4" diameter ball bearings from the hardware store. There is 1 ball bearing at the tip of each arm of the phone holder to give it a smooth rotation (like a lazy susan). I also bought a 1/4-20 threaded insert from the hardware store for the center of the base. I cut down the length of the threaded insert using a dremel and a cut-off wheel. The theaded insert will do double duty. A bolt will thread into it from the top to hold down the phone holder. You can also thread into it from the bottom to mount it on a tripod.
On the bottom of each arm tip there is a hemisphere cutout for the ball bearings. The center has a thru hole for a bolt to pass through and hold the holder to the base. I had to very carefully drill out the center hole so that the bolt fits freely though the hole. The bolt is only meant to hold the two pieces together, but still allow the top portion to rotate freely, so don't tighten it down too much.
The mount for the phone doesn't hold on to the phone as planned. In revision 2 I'll have to wrap the corners around further to the front of the phone and stiffen up the cradle and the supports. For now a little double sided tape will work to try it out.
Step 6: Summary and the Next Revision
I've tested my finished product out and compared panoramic pictures taken with and without the fixture of the same scenes. Does the fixture help? A little. Was it fun to make? Absolutely! The pictures that I have taken are connected together more seamlessly. However, they are less focused. When I rotate the phone I can see it shaking. I'll post some pictures soon. I'm trying to get some good horizon pictures, but haven't had much luck yet (I accidentally deleted some and other nights it's been too cloudy and there wasn't a good sunset). So my final conclusion is that this could be a very handy tool to have with some more refinement on the design.
Upgrades for Revision 2
- Add ribs to stiffen up the supporting arms that connect the phone holder to the base. This will keep the phone from bouncing around while the picture is being taken.
- Add ribs to strengthen the phone holder.
- Lengthen the 'Fingers' on the phone holder corners so that they wrap around to the front of the phone. The material is flexible enough that you should be able to snap the phone into the holder.
- Make the design into one printed part rather than two parts that need assembly. From what I've read 3D printing is completely capable of printing moving parts. Printing the bearings, center connector and tri-pod thread could result in an instantly ready to use fixture rather than requiring extra time to assemble and running the risk of breaking something in the process.