Posts Tagged ‘Robotics’

I previously posted about a robot arm built with cardstock and Arduino. The idea comes from a project on Hackaday.io called Cardware. The motivation for Cardware is that there are lots of hobbyist robotics components available like servo motors, controllers, sensors, etc, but to put together a complete robot of any kind you have to either buy an expensive kit (which may not even be available depending on where you live, e.g. Amazon does not ship to Thailand) or have the tools and expertise to fabricate something like 3D printed plastic or laser cut MDF body components. The talented project owner of Cardware developed plans for folded card stock as the body components that can be assembled into a complete robot.

There are multiple advantages of this approach:

  • Availability – card stock, or something similar, and general purpose glue are available nearly everywhere in the world, although there may still be some challenges as I discuss below in the video.
  • Tooling – an internet connection and printer are the tools needed to be able to download and print the patterns on the card stock. Even in less developed areas there is usually a school or internet shop where this can be accomplished. After that all that is needed is a pen and a cutter to score and cut the pieces.
  • Cost – high quality card stock is inexpensive by Western standards. It isn’t cheap by local standards in Thailand (and probably many other developing countries), but one can substitute lightweight cardboard such as cereal boxes, although there are some issues (mentioned in the video below).

The are some disadvantages to this approach. Dimensional accuracy and stability are not tightly controlled and depend highly on the quality of your cuts and folds. As a result, one can easily end up with a robot that is not well aligned and does not move smoothly. Another disadvantage is the fact that cardstock is not nearly as durable as 3D printed plastic or laser cut MDF. Due to the clever design and folding the strength is pretty good, but pivot points wear rapidly. Durability can be improved a bit by using lots of glue such as PVA to strengthen seams. And pivot points can be strengthened by gluing in plastic bearings made from something like short pieces of tubing cut from ball point pen cartridges.

In the video below I demonstrate the early stages of a build of version 2 of Cardware. At this stage I am driving two servos with the Arduino Uno.

In the video below I discuss some issues with the materials used in Cardware. My focus is on how this robotics learning platform can be globalized so that learners in developing countries can easily make use of it. In Western countries it is easy to take for granted something like cardstock. But it could be a real obstacle in a developing country.

These issues aside, I went ahead with the next version of Cardware using cardstock rather than reclaimed cereal boxes. The designer did some very nice work on it and I encourage you to visit Hackaday.io to see more details about Cardware. I finished the papercraft part of the project and started installing the servos. At that point I did not have enough servos to complete the project so it was put on hold. Events have intervened since then so it is still incomplete and looks like this at the moment

Robotic quadrapod make from cardstock, hobby servos and Arduino MEGA

Cardware Quadrapod

I anticipate a new blog post once it is fully assembled with all servos and an Arduino MEGA as controller.

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An Arduino Uno combined with a multi-function shield makes a great inexpensive starting point for projects. I had an extra Arduino-compatible laying around so picked up a multi-function shield with the idea to use it as a teaching tool. It has a 4-digit 7-segment display, a buzzer, three pushbuttons, a trimming pot, and a number of headers for attaching additional things like up to three servos. That provides lots of opportunities to dabble and learn how to control physical hardware with Arduino code.

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Arduino Multifunction Shield

I originally had just a vague idea of how I would use the Arduino + multifunction shield for teaching purposes. But then I decided to combine it with a project I was contributing to on Hackaday.io. The project started out as something called Cardware (which has since evolved quite a bit). The concept is that there are lots of hobbyist robotics components available like servo motors, controllers, sensors, etc. But to put together a complete robot of any kind you have to either buy an expensive kit (which may not even be available depending on where you live, e.g. Amazon does not ship to Thailand) or have the tools and expertise to fabricate something like 3D printed or laser cut body components. The talented project owner of Cardware developed plans for folded card stock as the body components in which servos could be mounted and then the components assembled into a complete robot.

More details on the development of Cardware will be in another blog post. Now I will just jump to the finished result of combining Cardware with an Arduino Uno + multifunction shield.

I introduced this to the teacher who runs the coding club at my kid’s school. They are already using Code.org to teach primary school kids coding. The kids in the club make art and games using Blockly. Adding a real world physical component like this gets kids excited and is what makes robotics such a great way to inspire young learners. There are many kits available targeted at that space. But I like this approach because it is much more DIY. It is more challenging than snapping together pieces of a kit so more adult help is needed. The Arduino can be programmed using a Blockly-like tool within the Arduino IDE. So kids can actually program the robot arm to move the way they want it to.