7 things I’ve learned while building a CoasterBot


At last count, 625 makers have decided to create a bot for our awesome Robot Build, and I’m one of them!

My concept is a bristlebot built with four toothbrushes and a mini CD. I bought some wee vibration motors, one for each brush, and right now, I’m trying to figure out a bunch of factors, such as how to keep the weight down — will the bristlebot be strong enough to lug around a solderless breadboard and 9v battery? How will the bot move beyond the drift induced by the vibration? The pic above shows it. I put the solderless breadboard on there just for fun, the final configuration probably won’t look quite like this. Since the picture was taken, I soldered wires onto the vibration motors and test-spun all four with juice piped in from my desktop power supply.

While I still have a bunch of questions, I’ve also learned a lot:

1. A good soldering iron is indispensable

When I got my start soldering, I used the infamous $10 Shack iron and it was terrible. There was only one setting — ON/OFF — and the temperature never seemed right for me. Eventually I bought a nice model on the opposite end of the spectrum, a beautiful Weller WES51, and it made the whole process much easier. You don’t have to go that high-end but avoid the $10 iron! Definitely get one with an adjustable heat setting, a nice solid stand, and a sponge. It won both in terms of convenience, and I felt, in the quality of my solders.

2. This project can be as easy or complicated as you want.

I’m building the coasterbot from the optional Jameco parts bundle because I want to learn as much as possible. But I’m also keeping in mind my main idea of the bristlebot. Do I really need the motor driver or the voltage regulator? What if I want to swap out the kit’s touch sensors with some other kind of sensor? The point is you can go basic with the kit, or skills and ambition permitting, go crazy and do your own thing. Right now, I’m erring on the side of crazy, which is a lot of fun but may not result in a working bot!

3. Know the tutorial. Love the tutorial.

Even if you have no intention of buying the Jameco pack, I very much recommend the tutorial that Matt Metts put together. In it, he describes how to assemble the Jameco CoasterBot in one hour. Matt did a great job explaining everything and beginners in particular will benefit from reading it. Also, if you haven’t signed up to the mailing list, make sure you do — you can do it on the Robot Build page, which also has articles, newsletters, and so on.

4. If you get the Arduweeny, don’t forget the cable

While the Jameco pack has pretty much everything you need, there was one notable omission, a USB-to-serial cable you’ll need to program the Arduweeny microcontroller. You can get the cable for about twenty bucks from the Maker Shed and elsewhere.

5. Double-sided tape is your friend.

If you’re still prototyping your bot, or aren’t sold on its final configuration, use double-sided foam tape to stick things together. For most bots, the holding power will suffice for the time being, and it’s lot easier and quicker than screws or superglue.

6. Don’t forget rule #2!

This is gonna be the hardest for some people, myself included. I am, of course, referring to the requirement that the bot be able to avoid obstacles. For my project, I bought an IR sensor and some IR LEDs with the intention of using that rather than a touch sensor. But how do you steer a bristlebot? I’m waiting on a small servo from Jameco and a toy helicopter tail rotor from Amazon. With any luck, my little propeller will be able to push the bristlebot around.

7. There’s still time!

Pleeeeeeennnnty of time. You could even slip in an online parts order for those critical missing components. But with less than two weeks, don’t wait too long. And bear in mind, part of the judging will be on how well the project has been documented, so take lots of pictures and write up some blog posts.

Discuss this article with the rest of the community on our Discord server!

My interests include writing, electronics, RPGs, scifi, hackers & hackerspaces, 3D printing, building sets & toys. @johnbaichtal nerdage.net

View more articles by John Baichtal