Remote control tarantula
From DDL Wiki
Contents |
Executive summary
Customer needs
Function
The Tarantula is a variant of commonly seen remote controlled toys. The user holds a controller which sends radio signals to the Tarantula and controls its movement. The appeal of this toy is the novelty of a large moving spider as a remote controlled vehicle. Also, the realism of the device adds to the user’s enjoyment by allowing him or her to scare others with it.
Forward Locomotion
The controller only has two outputs, forward and back. During “forward” the motor runs in a clockwise direction engaging the drive wheels through a gear system. The drive wheels are under the abdomen of the spider, while the steering wheels are under the head. When moving forward, the steering wheels are pointed straight and the spider moves in a straight line. The drive wheels are vertically offset from each other to mimic a “crawling” motion and add to the realism. Due to the high gear ratio, the movement is slower than most RC toys, similar to what one would expect of an actual spider. However, the toy only functions well on very flat surfaces, and will become stuck on carpet or small obstacles.
Leg Movement
When the motor is engaged, a turn table in the head of the spider also spins. This table is cam shaped which causes it to asymmetrically engage 8 levers which are connected to the 8 legs of the spider. As the turn table engages the legs they are lifted up, but pulled back down by gravity as the turn table disengages them. This up and down motion of the legs mimics the crawling of a spider and it is central to the realism and novelty of the product.
Turning
The spider has no specific steering mechanism; rather it turns when the motor is running counterclockwise or receiving a “backwards” input. The gearing is such that when the motor is running backwards the steering wheels turn counterclockwise approximately 45 degrees. This causes the spider to turn while it is moving backwards, allowing the user to control the eventual destination of the device.
Power Train
The spider is powered by two AA batteries connected in series. This powers the small motor and electronics (circuit board, LED eyes). The motor is connected to a gearing system with a large gearing ratio by a worm gear. This results in a slower movement, but higher torque on the drive wheels.
Product use
Components
Part # | Part name | QTY | Function | Materials | Manufacturing Process | Picture |
---|---|---|---|---|---|---|
001 | Cover Screws | 13 |
| Steel | Cold headed, Thread Rolled | |
002 | Inner Flat-headed screw | 2 |
| Steel | Cold headed, Thread rolled | |
003 | Battery Cover | 1 |
| Plastic | Injection Molded, hand modified | |
004 | Back Wheel housing | 1 |
| Plastic | Injection Molded | |
005 | Back Wheel | 2 |
| Plastic | Injection Molded, smoothed | |
006 | Small Leg | 4 |
| Plastic | Injection Molded | |
007 | Medium Leg | 2 |
| Plastic | Injection Molded | |
008 | Large leg | 2 |
| Plastic | Injection Molded | |
009 | Feelers | 2 |
| Plastic | Injection Molded | |
010 | Driving Wheel 1 | 1 |
| Plastic | Injection Molded, smoothed | |
011 | Driving Wheel 2 | 1 |
| Plastic | Injection Molded, smoothed | |
012 | Plastic Protection housing | 1 |
| Plastic | Injection Molded | |
013 | Back Wheel Axle | 2 |
| Steel | Cut wire, smoothed | Image:RC Tarantula Part 013.jpg |
014 | Battery Cover Washer | 1 |
| Plastic | Punched | Image:RC Tarantula Part 014.jpg |
015 | Gear 1 | 2 |
| Plastic | Injection Molded | |
016 | Gear 2 | 1 |
| Plastic | Injection Molded | |
017 | Gear 3 | 2 |
| Plastic | Injection Molded | |
018 | Gear 4 | 1 |
| Plastic | Injection Molded | |
019 | Axle 1 | 1 |
| Steel | Cut wire, smoothed | |
020 | Axle 2 | 1 |
| Steel | Cut wire, smoothed | |
021 | Axle 3 | 1 |
| Steel | Cut wire, smoothed | |
022 | Axle 4 | 1 |
| Steel | Cut wire, smoothed, stamped rough areas | |
023 | Axle 5 | 1 |
| Steel | Cut wire, smoothed, stamped rough areas | |
024 | Axle Cap | 1 |
| Plastic | Injection Molded | Image:RC Tarantula Part 024.jpg |
025 | Switch Assembly | 1 |
| Circuit Board (silicon), metal wires, plastic switch | Assembly | |
026 | Switch Cover | 1 |
| Plastic | Injection Molded | |
027 | Motor Assembly | 1 |
| Metal wiring, magnets, Metal casing, plastic gearing | Assembly | |
028 | Circuit Board Assembly | 1 |
| Circuit Board (silicon), metal wires | Assembly | |
029 | LED Assembly | 1 |
| Circuit (silicon), metal wires, LED | Assembly | |
030 | Tarantula exterior bottom | 1 |
| Plastic | Injection Molded, hand modified | |
031 | Tarantula exterior top | 1 |
| Plastic | Injection Molded, hand modified | |
032 | Battery Connector | 1 |
| Steel | Cut sheet metal | Image:RC Tarantula Part 032.jpg |
033 | Battery + connector | 1 |
| Steel | Cut sheet metal | Image:RC Tarantula Part 033.jpg |
034 | Battery - connector | 1 |
| Steel | Cut sheet metal | Image:RC Tarantula Part 034.jpg |
035 | Metal screw receiver | 1 |
| Steel | threaded cylinder | Image:RC Tarantula Part 035.jpg |
036 | Drive Wheel Mount | 1 |
| Plastic | Injection Molded |