Build Journal: Western Oregon Raceway
Preamble (10/13/21)
I’ve been racing for a year, and have decided it is time to build a track and host a race. I don’t have a lot of space, but that didn’t stop me from building an awesome model railroad.
Project Goals:
- Portable with easy setup and take-down.
- Realistic drag racing action.
- Child friendly (grandkids, maker faires).
If you’ve been following my Quest for the Golden One series, you know I have an electronic timer. I used my Nerf Chronograph knowledge to do this, but wanted to build something a little more robust, and perhaps something that others could build. Using a combination of off-the-shelf electronics and custom circuit boards, I thought a modular approach would work well. My approach to projects is to break it into discrete, testable steps:
Finish Line:
- Two IR-gates per lane to calculate speed as well as elapsed time (custom PCB).
- I2C bus displays to show speed and elapsed time (off-the-shelf).
Starting Gate:
- Two IR-gates to show staging and trigger start of race (custom PCB).
- I2C bus display Christmas Tree (custom)
- 9g hobby servo to start the race (off-the-shelf).
You will notice how similar the gates are. Can I do it with one circuit board?
Stretch Goals:
- Bluetooth wireless starting and time reporting.
- MP3 sound effects (for local events).
- Burnout smoke from vape pen hack?
So, here is what I know how to do:
- Realistic scenery (model railroading).
- Design and build electronics.
- 3D design and printing.
- Document and explain projects.
- Photography and video editing.
Here is what I need to learn:
- How drag racing works.
- Bluetooth communications.
- Logistics of running a mail-in race.
- How to make a compelling race video.
- How to build a community around a track.
I love learning, and sharing what I learn. One of my first steps was to go to a local drag race. Like die-cast racing, I found it a welcoming sport, filled with passionate people willing to share what they know. And so, the journey begins . . .
Open Source Philosopy (10/29/21)
Before I start getting too far into the details, I wanted to talk about Open Source because it is going to come into play in many areas in the project. Open Source, at its most fundamental, is about sharing openly. It means crediting people you are borrowing from, and sharing what you contribute. For my Open Source Turtle project, I credit those I borrowed ideas from, and share everything from CAD files, schematics, PCB files, software files, and the bill of materials (BOM). I also freely share instructions on how to build it.
You can Open Source to another level by utilizing Open Source software for the information you share so that no one will be limited by licences or proprietary formats. For me that means:
- LibreOffice for documents and spreadsheets.
- KiCad for electronic design.
- FreeCad for CAD.
- Arduino for programming.
- GIMP for photo editing.
- Inkscape for graphics and design.
I’ll be the first to admit, none of these match their paid counter-parts for features or ease of use, but as a hobbyist, I don’t need all the bells and whistles and certainly don’t want Adobe Creative Cloud bogging my system down.
The other argument against Open Source is people who want to make money from their ideas. In a lot of cases, the myriad of licenses do not prohibit commercial use. Additionally, there are companies like Adafruit and Sparkfun that are thriving using Open Source designs. There are people (myself included) that are willing to pay a premium for well designed kits that come with good documentation, tutorials, and support.
Enough preaching. Here is a quick look at Version 0 from more than a year ago?!
Discussion
This project looks great. I'll be following closely, as your build is almost exactly what I've slowly been trying to do with my test track (minus the event portion).
My test track is currently an Arduino Uno connected to a servo for the release gate, and to an IR-gate for the finish line. The servo is triggered via Excel, which also records the timing in the spreadsheet. Eventually, I was hoping to incorporate Bluetooth for start gate triggering and Wifi to record timing in Google Docs.
I have a few (self-serving?) questions:
1. How are the two IR-gates triggering the start of the race? Is it a check for the presence of two cars?
2. What start gate mechanism do you plan to use with the servo? Flip-up or tab pull-down? 3d-printed or off-the-shelf?
3. Do you envision end-gate timing to be based off of the servo-gate release, start gate IR-gate trigger, or something else?
Re: Bluetooth - another track looks like it may have some of what you need and posted plans/instructions on github here
Good luck!
- That remote project looks amazing. Looking at how actual drag racing works, I'm think of having a pre-stage and stage sensor. Bluetooth is going to be too slow for sending timing signals, so it will have to be a wired signal. Still thinking about the servo arm. — TheMakersBox
Glad to welcome another model railroader to this adjacent hobby! Looking forward to seeing what you produce! Maybe it will inspire me to finish mine, once it finishes its journey to the rock in the middle of the Pacific.
- I spent some time on in the middle of the Pacific. Seems like a year is about where you get Island Fever. — TheMakersBox
Display
I'm going to break project this into three separate sub-projects:
- Display
- IR gates
- Start gate
The display is by far the easiest, so let's get that out of the way. I'm using off-the-shelf displays and have designed the enclosure.
The display is driven by a microcontroller using the I2C bus. This means that multiply displays can be easily controlled using just four wires! Each sign has two displays, and I'm intending to have a sign on each side of the track.
I'm not putting to much effort into the scale. My main concern is being able to see it from the starting line. There are not a lot of options size wise. These displays are 0.56" high and cost about $10 each. There is a 1.2" high version at twice the price. I think the 0.56" version is a nice compromise on visibility and scale, but the true test will be when we start filming.
To make this, you have to have some beginner soldering ability, and not be afraid to modify some code. Adafruit provides excellent instructions for both at learn.adafruit.com/adafruit-led-backpack/0-dot-56-seven-segment-backpack-assembly.
You will also need some 3D printing. I've published all the files at www.thingiverse.com/thing:5145637. If you don't have a printer, check your local maker spaces or even library. They are everywhere these days.
I'm happy to have my brain picked regarding logistics, live events, and community-building...and the drag racing thing I've been doing a long time too :) Shoot me a PM or email (or post) with any specifics you may have and we can get going that way. All those topics are pretty big and I could probably write a short book about it all.
I'm excited to see what you come up with for a start/finish accessories. I have yet to find a product that does exactly what I'm looking for and see your journey/blueprints might be just what I need to get my track updated.