All I can say today is “WHEW! It’s almost done!” I’ve been working 14-hour days for the past few weeks in order to get the car done in time, and there is finally a light at the end of the tunnel. While the car has yet to drive under its own propulsion, the Power Racing car has been shipped to California for the Power Racing Series. If you’re thinking this sounds crazy, you’re absolutely right – but let’s take a look at how this will all come together at the last minute live in California at Maker Faire!
When I left you last week, the motor mounts and battery mount had been welded to the chassis, but there was still a lot more fabrication left that needed to be completed. The vehicle still needed bumpers, steering, and a place for the driver to sit. With a poorly cobbled-together plan, I started cutting and welding together square tube in an effort to make our bicycles look a little more like a vehicle. After many hours and a lot of sweat, I came up with this:
The driver sits on the little box between the two seat tubes and places their feet on the two square tubes running to the front of the frame. The steering was completely fabricated from scratch as well. We made two plates that connect to the front forks of the bicycles. On these plates I welded a handle on an extension as well as a ball joint, which allows me to connect the two forks so they are always turned to the same angle.
As I was welding together the frame, I noticed something odd on the ground and decided to take a picture. Do you see anything interesting in this picture of the floor?
To give you a hint, I’ll tell you that the cable you see is the ground cable for a welder. Can you see the metal filings next to the cable? What about the ones that used to be next to the cable before it was moved? Because of the high currents flowing through the welder’s ground cable, the metal dust has actually aligned itself to the cable. This is a physical display of the right-hand rule in action! Isn’t science cool?!
While the metal filings were fascinating, there was still a lot of work to do on the car. Now that we had the right belts in, I could finally mount the drives to the frame and get the chain sized correctly.
With most of the metal fabrication work behind me, I turned to focus on other important aspects of the car. To enter the race, I needed to at least make an effort to make our two welded together bicycles look like a power wheels vehicle. After test fitting a few of the body panels I procured, I was able to attach them to the vehicle with some zip ties.
At this point, the chassis was complete and ready to ship to Maker Faire! Before I sent it off to be shipped I took this picture so y’all could see what the car looks like with a person in it. By no means is it comfortable, but race cars are meant for speed – not comfort.
By this point, you’ve probably noticed that you’ve never seen an action shot of the car. There’s good reason for that... It still doesn’t drive. While I thought I had fixed the motor driver board, there were some additional issues I hadn’t found yet. I tried fixing them and even ended up drilling out a via and jumping a trace over the via when I was reworking a board. I am one with my soldering iron.
Sadly, this still didn’t fix the board so we are going to be using a different motor driver board during the race. I’m currently working on getting this other motor driver board working with our motor and throttle.
The pressure really is on! Will we be able to get the motors running in time for the race? Will we be able to get the car assembled when we get to California? Will we be able to cobble together a race telemetry system using TI Launchpads and SensorTag products on site? There’s still a lot of uncertainty, but I’m confident everything will come together and be awesome! Come out to Maker Faire and show your support for team “My Little PWNies” as we PWN the competition! Don’t forget to vote for us on the Moxie board! Look for our Moxie label:
Read the first three blogs in our Maker Faire Power Racing series:
