I've built a few experimental robots in the past and, to be honest, they all looked the part. They were nothing more than circuit boards with wheels glued on.They did help me learn, but they just didn't feel like completed robots. The main purpose of this project was to combine electronics and 3D fabrication into a robot complete in both form and function. A fun robot with a sleek look and a bit of personality. The second goal was to make the robot as small as possible, smaller than half a ping-pong ball (hence the name).
In this Instructable I will share what I've learned while creating the Pingbot. Included is information about PICAXE Micro-controllers, surface mount soldering, PCB design, Autodesk's 123D 3D design software and 3D fabrication, rechargeable lithium-polymer batteries, as well as a few painting techniques.
Included are schematics, a PCB layout, PICAXE code, 123D model files and pictures of the construction process. You will also find a wealth of links to detailed information that is relevant to the project, as well as suppliers for the parts used in the Pingbot.
Update
MSurguy, a friend I made through this instructable, has finished his own version of the robot. Instead of a 3D printed shell he used an actual pingpong ball cut in half, check out the video: http://vine.co/v/bJViYxMAzTw
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Signing UpStep 1: Body Shell 123D Design and Fabrication
Choosing a Material
It is important to choose a material before you start working on a model as each material has different guidelines that you must follow while you are designing. The materials vary in the minimum wall thickness, minimum detail size, flexibility, and other properties. Some materials are weaker than others, large models made from them may need inner structure to support the weight.
I chose to have the shell for the Pingbot printed from the Durable Fine Plastic. This material is strong enough to be used as a working prototype and its minimum detail is a minute .2 mm. It is more costly than other materials, but since the cost of a model is partially determined by its volume, the shell was incredibly inexpensive to have fabricated. All totaled, it uses less than 1/3 cubic centimeter of material.
Creating the 3D Model
Although it was printed as one solid piece, the 3d model was made from separate components that come together to make a hemisphere. This was necessary as it allowed the edges of each of the parts to be rounded off.
To begin I created a hollow hemisphere with a 1mm wall thickness. I then copied/pasted the original shell, drew new shapes, and extruded these new shapes to subtract (and intersect) from the hemisphere. After completing all the parts I beveled the edges to create the seams. I've included a couple of pictures of the process.
While designing this robot's shell it was important to remember to add holes for the components that needed to be accessed from the outside. For the USB connector and micro-switch I use the PCB design along with the components' data sheets to determine where, and how big, the access holes needed to be. I also added some holes in the back to help let out the sound from the peizo speaker (the speaker was plenty loud and these holes were likely not necessary).
Upload and Fabrication
In order for a model to be printed, all the separate components need to be welded together to create one solid piece. Once this is done It can be saved as a STL file and uploaded for printing and sharing. (You will need to be logged into 123D to be able to save as an STL.)
This video is of the Object Connex 3D fabrication machine, which is likely close enough to the model of machine used to create the Pingbot shell. It demonstrates how the machine prints the model in layers along with a support material. When fabrication is complete the support material is blasted away leaving the final piece.



















































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As for marketing, well, I'm learning about the process, but I'm certain that this will never be made into toy that your going to find at the store. However, the kit bundle version should be available soon; it has been submitted to Club Jameco and is making the final rounds now.
Thanks for checking out the project, happy you liked it :)
The idea came from all over the place. For the look of the robot, the movie "Batteries Not Included" had a major influence. As for the actual robot, I'd seen several of these little picaxe robots, such as the one by Mikey77 here on instructables, and wanted to make one of my own as a way to learn Picaxe and li-po battery charging.
The first road I would try would be to add a sound sensor. Then you could set up 3 IR/Sound beacons in a room. The robot would receive a light and sound signal from the beacon and measure the time between the IR and audio to determine distance. After getting this info from all three beacons the bot could then triangulate its position.
In theory anyway. I personally don't quite have the skills to tell you exactly how to do this, and I'm not sure if a PICaxe chip would be able to handle it. I bet an Arduino/Atmell would though.
Another possibility would be to use a GPS sensor. It would be a little big to fit into a robot this size, but those sensors seem to get smaller everyday.
Hope this helps and thanks again for the interest :D
I agree with everyone else; the first thing I thought of was the little bots from BATTERIES NOT INCLUDED. The little semi-spherical dome also reminded me of a little R2-D2 unit, yet unique. I did some sketches a few years back (inspired by the cute little robots in the Calvin & Hobbes comic strip - which also reminded me of R2-D2.) I like the idea of a unique little artoo-like bot - and a community of them created by other people.
I am an electrical engineer and design this kind of thing in my spare time as a hobby. I am extremely impressed by your expertise in varied areas of design - electronics, pcb fabrication, 3D model design, etc. I do all of these things too, and I have been searching and searching for exactly this type of thing to inspire some of my new creations! Finally, someone with originality and creativity!!!
Anyway, kudos! This is fantastic - and possibly the best, most thorough, and most creative instructable that I have seen yet!
Aaron :)
I'm over the top ecstatic with the response this instructable has gotten, I kind of see it like a full circle of knowledge sharing. I goof off with this stuff purely as a hobby and a large percentage of what I know I've learned from this website. By writing this I was able to take that knowledge and inspiration and put it back into the creative machine so it can be reprocessed by others. That feeling literally makes me giddy like a 12 year old.
You mentioned some fantastic ideas that I'm hoping to add to Pingbot v2, and I know exactly the Asimov story your talking about. While we are on the subject, I learned about these robots shortly after writing this instructable and I think they are just the sweetest thing ever. They are like, Pingbot advanced level 10 without out the hard candy shell. I have a feeling that you'll find it fascinating:
And check this out, you can download the manual for free!
http://www.k-team.com/mobile-robotics-products/kilobot/manuals-downloads
http://www.instructables.com/id/SOCBOT-the-next-generation-vibrobot/
Biometronics didn't use transistors to power the motors. Instead, each motor was powered by two pins simultaneously to get enough mA.
I like that your design saves pins for use with lights and sound. I'm a big fan of the PICAxe for people like me who don't have time to delve into the more complex languages. You should add the tag "picaxe" to this instructible. I search for picaxe projects from time to time and there aren't many to find on this site.
I'm becoming a big fan of PICaxe too, they have really helped introduce me to microcontrollers. Plus most of the things I want to make don't really need advanced programming.
Light and sound are super important lol. As advanced as robots have gotten I still think that R2D2 tops them all in personality and all he did was beep and spin his head.
I'm adding the picaxe tag right now, thnx again :)
If you'd like to see this as a kit goto the link and vote for it.
Click on that and you will be able to download the full size image.
http://www.instructables.com/file/F58QMCVH267L4NP/?size=ORIGINAL
Thanks for all your help. Now I know how to look at different pictures too. I look forward to seeing more of your work - this is awesome!
Although your little bot is cute, it would be great if it did something slightly more useful / interesting than just dance around (something that a mere BEAM robot does).
Ideas... I don't know your level of programming proficiency; but if you understand IR communication protocol (like SIRC), you could make your robots have two-way communication capabilities - transmitters and receivers. That way, they could communicate between themselves and perform interesting team behaviors - to accomplish a common task. I get this idea from a short story that Isaac Asimov wrote about some mining robots which performed duties like a hand and its fingers. It would be interesting if each of the little robots had its own unique function and could perform a different task to accomplish the team's common goal.
Also, if you used some geared motors and wrote some good path-following algorithms, you could put a pen in the center of your bot and have it follow a path that would enable it to write messages on a piece of paper - or something like that.
Just some ideas...
Aaron :)
1) great project Idea
2) great implementation
3) great instructions
4) Totally awesome results... and repeatable too.
Two thumbs up.
Jerry
This guy is already in two contest and I really want to make something new for the Laser contest. I hope you like that one too and vote for it ;) Thanks again!
http://mtmeyerstudio.com/wp-content/uploads/2009/01/kids2.jpg
Awesome little bot and yep, I thought Batteries Not Included when I first saw it too.
When you have applied the tape fist paint it in the color that's under the tape. Wait until the paint is dry. Then apply the color you want.
What you do is first filling the holes under the tape with the color already there. So you won't notice it. Then apply the other color which can't run under the tape.
Only disadvantage is that you have to wait until the filling paint is dry.
Advantage is that you have razor sharp edges.
Feel free to ask questions or give suggestions!