So I am always looking for a good medium to start off with for a project, and I noticed this toy at CVS for $7. It was cheap, interesting and had plenty of space for electronics!
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Step 1: Disassembly
So there are only two screws holding three pieces of the toy together, one in the front and one in the back. Once I removed those I could easily lay everything out. The middle piece showing the seats could be put in recycling as it would take up much needed space. The steering wheel met a fate with some clippers and was removed, it was going to get in the way and I was going to diffuse the windows eventually. At this point I noticed that the base was very flimsy and would need reinforcement, which I would do later.
Step 2: First Problem, How Will I Turn This On
So I obviously needed a button, but didn't see a good way to integrate it into the shell without doing too much damage, also the shell isn't able to take too much stress I determined. Fortunately I have a Prusa i3 mk3 3D printer, which is ready for the job. Using tinkercad I designed this simple box with holes for the wires and a large hole on the top for a momentary push button.
Step 3: Electronics
DISCLAIMER: I am not amazing at soldering and it's still a skill I am working to perfect. So yes the soldering may appear a bit ........ sloppy.
The brain of this is an Arduino Nano V3 clone, found on gearbest.com or banggood.com for about $2-3. This is a great board, which I have used on many projects. It's one shortcoming is that it lacks any wifi or bluetooth capabilities, fortunately we don't need any of that for this project.
So I needed three sets of cables for this project, the first were the power cables. For this I purchased a cheap 120v AC to 12v DC power supply off of amazon for about $6. I cut off the end, separate the positive and negative and stripped the end of each wire. Just to confirm which one was positive vs negative, I checked with my volt meter then put a blob of solder on the positive end. You can see that blob in the first two photos. I ran the power cable through both cable holes the 3D printed housing. Eventually I soldering the positive cable to the VIN pin on the board and the negative cable to a ground pin. This board is able to safely regulate power of 6v-20v through the VIN pin. DO NOT use the 5v pin for power input unless you have a regulated 5v power supply.
The wires you see besides the power lines are recycled (salvaged) wires from an old desktop I had. Didn't spend any money there, which is great, even though wire is cheap. I ran one wire from the 5v pin to one of the pins on the button and solder it in place. On the other pin on the button I soldered a second wire and ran that back through the wire hole to a 10k pull down resistor, which was also connected to a ground pin via a wire, then the output of the resistor went to pin 23 or A0 on the board.
The last set of wires are for the LED strip. This was used in a former project I did at home, and is a standard 5v, addressable, RGB LED strip. This had a 5v, ground and data cable attached to it, with the data cable going to pin D4.
Step 4: Locking the Wheels and Making the Bottom Stronger
Hot glue was used to "lock" the wheels and gearbox into place. It's a nightlight, movement is not really needed at this point. As I said earlier the bottom was a bit flexible (too flexible), so I printed out two pieces of plastic at 100% infill and hot glued them to the bottom. This seemed to fix the problem well enough.
Step 5: No Need for Doors to Open, and Lets Diffuse Some Light
So using hot glue again, I sealed up the doors trying to keep the windows clear and not having the glue bleed to the outside. Next I printed out a thing sheet of white ABS at 0.25 mm thick on the 3d printer. it was good enough for about two layers. I sketched out the pattern that i would need for it to fit on the inside of the cab and cut it out using scissors. Once I had enough pieces to cover all of the inside, mostly focusing on the windows, I hot glued them into place. This will help make the end result appear to glow vs having hard light coming directly from the LEDs.
Step 6: Putting Everything Inside (MORE HOT GLUE)
So to get the wires and board to stay put I went a bit overboard with the hot glue. I also used it to seal up the soldering joints a bit to make sure that they don't come apart (just in case) and to have a little extra protection from any potential shorting/sparking (rare but why take a chance). It's not the prettiest, but it works well enough and really nobody will ever see it when it's closed up.
Step 7: Close Everything Up
So I screwed the top and bottom of the Vanagon back together and then with some super glue closed up the power button case. I'm pretty happy with how it came out.
Please let me know what you think!
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