Introduction: StorageBot - Voice Controlled Robotic Parts Finder


I created the StorageBot to help solve a problem experienced by most Makers. After many years of accumulating thousands of parts stored in storage bins, I began to go crazy looking for parts scattered between so many of these bins. The hardest parts to find were always those rare miscellaneous parts that were thrown somewhere into a "junk" bin. StorageBot solves the location problem by listening to my voice commands, processing the location of parts from a master database and then delivering the matching bins in a manner that only a robot can do!

StorageBot does have a bigger picture when it comes to purpose. I explain in my video that it's not about building a StorageBot that's important, but rather it's the skills we can learn from such projects that help to enrich our knowledge and inspire us to build the next great thing or start the next cool business. 

In this Instructable you'll gain insights into the electronics, mechanics and software systems used to create useful projects by utilizing commonly available components such as the Arduino and stepper motors.

I've included a bazillion pictures and files. Source code for the Aduino program, source code for the Visual Basic voice recognition software, DXF files for the ABS parts, schematics for the electronics, 3D files drawn in the free Autodesk 123D program, parts list, etc... It's all here!

If you find this project inspirational and helpful then don't forget to vote for it in the ShopBot contest. I would use a ShopBot to create the ABS parts, aluminum parts and vaccuum form molds for my next generation home robots.


Step 1: Secret Exposed & Project Outline

The video above gives you a glimpse into the frame and mechanisms required to physically push out each bin based on the voice commands.

I'll describe the system by breaking it into the basic components. Here's an outline:

- Building the pine frame
- Building the x-axis
- Building the z-axis
- Building the y-axis
- Buldling the electronics
- Voice recognition software

Step 2: Autodesk 123D & Pine Frame

The StorageBot frame is constructed out of pine wood. All of the materials can be purchased at Home Depot. The plastic storage bins can be purchased from Harbor Freight. See the attached bill of materials for quantity and pricing.

When buying pine wood from Home Depot make sure you spend time selecting the best pieces of straight wood. I found the wood at the top of the stack is typically the most crooked pieces. Some of this lumber may be returned items and obviously people would return the worst of the pieces. Here's a trick to help determine the straight pieces. Place the piece of wood on the flat concrete floor and use the floor as a straight edge. Stay away from wood that is twisted along the length. Long pieces of wood that bow slightly in the middle can be ok if a later process such as screwing into the final framing straightens them out.

I modeled the pine frame using the free 3D CAD program from Autodesk called 123D. You can download the program here:

The cool thing about this program is that you model the components of your systems and then connect them together using something called constraints. In 123D constraints are under the Design Intent \ Assemble Icon. With constraints I can tell 123D to take 2 separate pieces of pine wood and align the edges to each other. Another useful feature of 123D is the Browser history along the left side of the screen. With this browser I can easily turn components on and off by just clicking an "eye" icon for each component. I used this feature in order to generate the step by step images for the frame construction.

The 123D model of the pine frame is attached below as a zip file. Have fun playing with 123D and be sure to watch the tutorial videos on YouTube.

Step 3: Building the X-axis

X is the axis that moves between the left and right side of the StorageBot. This axis also has to support the weight of the other axes, Z and Y.

Like many Makers I sometimes struggle coming up with the best design approach. My first attempt at prototyping the X axis was unsuccessful due to binding issues.  When building any rail system mounted to a wooden frame one has to compensate for wide build tolerances. For example: the wood isn't always straight, there may be warpage with temperature and humidity, cut lengths are slightly different, etc. The final solution I came up with was inspired by a rail system that was already used in my house. It so happens I have pocket doors and the rail system used on those doors can also be adapted to the StorageBot.

Pocket door hardware is an inexpensive and simple system for producing linear motion while hanging a lot of weight such as a door (or equivalent on the StorageBot). See the attached pictures on how I adapted this simple system. This is a great example of how being observant to the world around you can provide insights into solving problems.

Step 4: Building the Z-axis

When I designed the x-axis I was also thinking about how the z-axis would integrate into the design. It was obvious that the "door frame" being hung from my pocket door rail system would serve as the frame for the z-axis. The z-axis in this case refers to the vertical movement between the bottom and top levels of the StorageBot.

I already determined the z-axis would be belt driven and there would be a drive pulley and an idler pulley creating the ends of the belt system. When the belt moved it would have to move a carriage up and down in the vertical direction.

The challenge was coming up with a low cost way to guide the z-axis carriage along the vertical direction. There was already a vertical frame made out of wood so I wanted to use that as a guide. Using wood as a linear guide can be tricky due to sticking from friction. I finally came up with a solution based on some past tinkering with a bin full of spacers. Once again, curiosity paid off.

In the attached pictures you'll see how I used two different sized spacers, one made out of aluminum and one made out of nylon to form a low cost roller guide. Who ever knew playing with a bin full of spacers and noticing how some fit within others would pay off!

Step 5: Building the Y-axis

With the design for the X and Z axis finished I had only one more mechanical hurdle, the Y axis! This axis would be the one responsible for pushing out the storage bins (like a finger). Basically the X and Z axis would position some type of  "finger" in front of the storage bin that needed to be pushed out. The storage bins are fairly easy to push so I didn't need a big motor. The biggest challenge was the need for about a 3" finger throw and the appropriate compact mechanism.

The solution I came up with for the Y-axis was a rack and pinion system. The rack is essentially a toothed rectangular bar that is driven my a toothed circular "pinion" gear connected to a hobby servo motor. By picking the length of the rack and the number of teeth on the circular pinion gear I could now control the throw distance of the "finger". A rack and pinion system is another common way to convert circular motion to linear motion. In fact, it is used widely in the ShopBot system. See the attached pictures for the rack and pinion design. I'm fairly happy with the compactness and adjustability of this design when using different brand servos and different size pinion gears.

Step 6: Building the Electronics

When designing the electronics I wanted to use as many off-the-shelf parts as possible to ease construction. See the bill of materials for part numbers and suppliers. Once you buy and mount the components the wiring is basically all point to point wiring. There's very minimal soldering. You will need to solder two 10k resistors connected to pins 2 and 3 of the Arduino compatible board. You will also need to solder to extend wires from the stepper and servo motors.

The code running on the Arduino basically translates serial commands from the PC computer. These commands are then used to perform the following:

- moving the x-axis stepper motor
- moving the z-axis stepper motor
- moving the y-axis servo motor
- reading the x and z axis limit switch
- controlling the LED strip

Controlling stepper motors are very easy. Each stepper is driven by a driver board. By sending a step and direction signal from the Arduino to the driver board the motor can be made to move forward or reverse by one or more steps. 

The servo motor for the y-axis is also very easy to drive. The servo actually contains a motor driver board internally. A certain type of digital waveform is sent to the servo to make it move anywhere between the extreme clockwise and counter clockwise positions. Scope captures of this servo waveform are in the attached pictures.

Step 7: Voice Recognition Software

The voice recognition software runs on any old computer or laptop running MS Windows. It uses the Microsoft Speech SDK and a custom Visual Basic 6.0 application based on the SDK sample programs. You can download the speech SDK here:

After installing the SDK be sure to train the speech engine by going to the speech setting under the Windows control panel for more accurate voice recognition. I found the speech recognition doesn't always work that great. I believe the stuff I've seen on the iPhone and Android devices where you can speak more naturally are much better. Nevertheless, the MS SDK is good enough to start experimenting with voice recognition technologies.

There are 2 main functions of the application software. One is to handle speech such as voice recognition and text to speech output. The second function is to take the voice commands and search for the associated parts and bin locations within a master database. This master database was originally generated in Microsoft Access.

Source code for the program is attached as a zip file. You will need Visual Basic 6.0 to modify and run the application.

Step 8: Conclusion

I wanted to end by showing examples of how the systems used in the StorageBot are commonly found in many successful products today (ie: ShopBot, MakerBot, garage door openers, CNC conversion kits, etc).

I hope the many ideas presented in this instructable inspires you to create the next great products!
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