Problem: I have a game on my phone that requires user input every so often in order to avoid being attacked and loosing my hard earned gold.
Goal: Design and produce a phone stand that can tap a stylus on the screen to keep me alive. Win laser.
Wish list: Make it programmable so the stylus would touch different parts of the screen in different orders, and make a sudo automation for future tasks.
Step 1: Brain Storm!
I saw a project a few months ago that took a marker and drew the time on a whiteboard. Because of the scale of the project, I immediately though "this could work on a phone!"
If I could combine the simple stand, with the basic movement of this "RoboClock" project, it would accomplish my goals!
Step 2: Sketch a Basic Design
As much as I like to work and design in 3D programs, they can be a little overwhelming for the creative portion of the project. I did the initial sketch in a 2D program, just to get concept and scale hashed out.
Step 3: What Parts Do I Need to Make This?
When working in 3D its important to have all the parts that interact modeled together. Here is the list of items i'll need modeled:
I'll usually search www.yeggi.com for the parts. Lets assume I found them all in the correct format for this project and was able to import them into my 3D program of choice...
Step 4: How Will the Rest of It Be Build?
Its very rare to be able to just take other things and directly connect them together. For this project I'll need to design a bunch of pieces, but how will they actually be made? I would love to be able to 3D print it all, but I don't have access to a printer large enough! Luckily, it looks like most of the parts in the RoboClock are flat. Can I design this project to be laser-cut? or for us common folk, cut out of a piece of foam board?
I'm going to try for the foam board.
Step 5: Foam Board Constraints
- Foam board is basically a thin piece of foam sandwiched between 2 pieces of glossy paper.
- It comes in different thicknesses, but the most common is 3/16 of an inch (about 5mm).
- It is usually cut with a razor and a ruler.
- It can be made into sharp corners nicely, but its difficult to make round edges with a razor.
- As a general rule, the part should be make twice as wide as it is thick.
- Hot glue is the best way to join 2 pieces.
- It will hold screws, but the threads wear out quickly.
- Movable joints can be difficult, but can be accomplished if they don't hold much weight.
- Would probably be great to cut with a laser!
Here are a few other instructables related to foam board projects:
Step 6: Import Each Item Into Its Working File
Most of the 3D files downloaded are in .stl or something else that isn't what we're going to be working in. For Solidworks I need to open each .stl file, and save them as a .part file (.part is the native file Solidworks uses). I end up with a .part file for each of the parts mentioned in step 2. Note that nothing is connected yet.
It is very important at this step to make sure that each part is scaled correctly.
Its also important that the first piece your going to work with (in this case its the phone) is oriented the way you want it in the assembly. For this project, I rotated it back 30 degrees to allow for a good view on my desk.
Step 7: Make an Assembly
At this point I have a bunch of files in the computer that can't interact with each other. I'll solve this by putting them all in one assembly file.
I open up a new file and select assembly. Once this new assembly is open, I import all of the parts I made into .part files. Solidworks requires a main part that is fixed in space. For this project, I went with the phone itself. The rest of the parts can be brought in as parts of the assembly, and left to float in space.
Step 8: Make New Parts
Now I get to start making my own parts. The best way to do this is to work off of the fixed part (the phone) and start to arrange my other pre-made parts where they would need to be.
I make a quick sketch, then come back and constrain the lines and adjust the size. It helps to fix some lines so you have a basis to work from.
Step 9: The First Part!
This is what the first new part looks like. It still needs work, but now is a good time to make sure its saved with a meaningful name.
I open the part by itself (outside of the assembly file) and work on any details (like the hole for the servo). When i'm done I save it, and go back to the assembly file. The assembly automatically updates the part.
Step 10: More on Assemblies...
In Solidworks, assemblies are used to group parts for movement. In this design I'll have 2 distinct groups that move on their own. The first one is the phone base (which doesn't move). The second will be the 2 servos mounted above the main base and the arms for the stylus. The phone exists outside of these assemblies since it doesn't need to be there (its only there for reference).
On this project I built the entire first assembly, then moved them into a sub assembly of the file. I'll make another sub assembly in the same file and start on the top part.
Step 11: Make It Real
Lets assume that this design works and I want to make it a physical device. I open up a new assembly, and make a part that is the size of a piece of paper (in this case, that's 11x17). I then drag all of the individual parts from windows explorer into the assembly. Once they are all there, I arrange and mate them to the paper.
From this "cut out" assembly, I make a drawing (Solidworks has a function that will make a drawing from an assembly) and print it.
Once its printed, I double check the scale with a ruler, and glue it to a sheet of foam board.
Step 12: Cut All the Parts Out and Start Assembling
I then cut out all of the parts and make sure the individual components fit (I really with I had a laser...). Nothing ever fits right the first time!
Now is also a good time for a dry fit, for this I used some screws (#6x1" and #4x1/2") I had laying around. In order to put screws through he foam board, it helps to put a hole through the sheet with a nail thinner than the screw.
Step 13: Mechanical Connections
This project has a few mechanical connections to mention. I'm not proud of them all, but they work for this version of the project.
- "elbow" joints - I used one of the screws to put a hole in one arm, and keep spinning. The threads eventually wore out and I then screwed it into the other arm. This gave me a decent connection for a little while, but I ended up using a nut, bolt, and washers.
- Flip top connection - this is the connection opposite to the servo. Its just a screw through the outside foam board, half way into the inside foam board. Its a very short range of motion, so I think it will fork for a little while.
- Connection from servo horn to foam board - The #4 screws go through the foam board and into the servo horn. The holes in the servo horn need to be drilled out slightly in order to prevent the horn from splitting.
- Stylus holder - I went very simple with this one. Its just a friction fit on one arm, and a looser fit on the other. I don't need to worry about the stylus rotating since its round. I also end up using the stylus as the hinge point between the 2 arms.
Step 14: Final Mechanical Design
This is the final design. I had to use my charger in order to take a picture (since I've been using my camera phone).
Issues I notice already:
- It falls backwards when the arms are back.
- I didn't account for the case or flip top on my phone.
- The elbow joints are crap. I'm not sure i'll get a consistent "tap" when I use the device (fixed by adding nut/bolt/washer).
- Screws stick out the bottom.
- Upper arm is too long, I'll need to move the joint higher in order to get a full range of motion.
whatever. The important thing is to note the issues and fix them in the next version.
Off to wiring
Step 15: Wiring
I didn't account for a breadboard and I don't want to put the effort into etching a board for such a simple device, so I'll just wire the servos in the air.
This is probably a good point to note that I did add an on/off toggle switch... so if the device is on, it will tap on the screen. This was added during the programming and debugging.
Very important! In order for the stylus to work, it needs to be connected to the ground pin of the arduino.
Step 16: Programming!
Attached is the basic program which really doesn't do more than tap on the screen. I'll continue to work on the programming to allow a little more control over everything. Maybe.
Step 17: Its Alive!
Step 18: V2
After using V1 for a little while, I came up with a list of changes I wanted to make:
- Add fan so phone doesn't overheat! - not yet
- Make the phone fit better (original design didn't account for the flip cover) - done
- Make the frame prettier - done
- Stiffen the arms - done
- Stop if from falling over (better balance) - done
- Program smoother arm movement - not yet
- Program different sets of motion (taps to do stuff, not just keep it alive) - not yet
- Add lcd to tell what step its in - done
Step 19: What Would I Do If I Had a Laser?
If I had a laser I would probably rebuild a few of the items I've previously made out of foamboard and make them better... Maybe in instructable format. Vote for me!
Step 20: The End
Now that I've got it mostly working, I actually stopped playing the game (isn't that always the way it works?). Enjoy!