Whatever path you take, read through all the directions first, especially the Final Thoughts section at the end to learn about my mistakes, and hopefully not repeat them. I hope you will soon be building your own Electronics Learning Lab/Experiment Kit. If you like my Instructable, please vote for me in the Portable Workstation contest.
I was interested in learning about electronics so I set up a work bench with a few tools; a soldering/desoldering station, a computer, some basic hand tools, and a large cabinet with small drawers for parts. It turned out to be a very nice, simple workstation, but i spend a lot of my time in bed (I'm sick, not lazy) so it sat unused. In bed I was able to read several books on electronics and the Arduino platform, but that was just frustrating, so I decided to build a portable, self contained, learning/experiment lab. It needed to be light weight, self contained (hold parts, wires, arduino board and breadboard), and be easy to quickly pack up and put away. I had a Pelican 1200 case that wasn't being used, so I started with that.
Step 1: Parts List
(To build an identical kit, otherwise, your parts may vary)
1 Pelican 1200 case
3 large Altoids mint tins
6 Altoids small mint tins
1 medium component storage box
Parts (Hardware Store)
8.5”x11” x 1/8" Lexan sheets (2)
1/2” clear acrylic rod
4 small magnets 1/2" or smaller
"Super" Glue (Cyanoacrylate )
4-40# x 3/4" Nylon Nuts and Bolts
2-56# x 3/4"Nylon Nuts and Bolts
Du-Bro R/C Airplane Hinges Large
Du-Bro R/C Airplane Hinges Small
3/4" Brass Hinges (2)
Sew On Velcro
Foam Mounting Tape (Scotch Extreme Mounting Tape 20lb strength)
1 Arduino Mega ADK
1 Large Breadboard
2 Half breadboards
9-volt battery case
Adafruit TFT Display with SD Card (Product ID: 1480)
Adafruit White LED Backlight Module (Product ID: 1626)
Step 2: Step 2: Containers
For the main case i used a Pelican 1200 but you can use any size case as long as it closes securely. I used to have a small aluminum briefcase. If I hadn't given that away, I probably would have used that instead. With your main case selected, you now need to find containers for components and wires. I had a number of large and small Altoids tins, another small Pelican case (1010), and a similarly sized, but slightly longer and thinner clear box that an outdoor watch came in. As far as the component cases are concerned, any container that will stay closed on its own, should work fine. Altoids tins happened to be the perfect size for my main case, so I used both the large and small ones, and settled on using the watch case as well, for larger components.
Step 3: Step 3: Layout and Mock-up
I decided to first build a mock up out of cardboard. If you're using a different size box I recommend making a cardboard version first since it will help you test different layouts of your storage boxes, board and breadboard to find the most efficient layout.
The Pelican case is deep so I decided to make two levels, the bottom level for storage of components, and a top level for the Arduino board and breadboard(s). Two levels posed a problem though. To access parts, I'd have to continually remove the top or have component boxes floating around my bed. I decided to compromise and leave the large parts box (the watch box) underneath and make shelves in the top lid to hold the component boxes while I was working on projects. The other problem with two levels was keeping the top shelf in place when the box was closed while still maximizing the usable space inside. I decided to use posts, attached to the bottom of the inside of the box and magnets to hold the top shelf to the posts. If your case is larger, but thinner, you might be able to fit everything on one level. Using cardboard it's easy, and cheap, to experiment with different configurations.
I cut my cardboard templates larger than necessary and then trimmed them to fit so I could be sure the measurements would be correct and I would suggest doing the same. After finishing the cardboard main shelf, I experimented with different layouts of my storage boxes and breadboards to see what layout was most efficient.
You'll need to decide what Arduino board you're going to use. I decided on the Arduino Mega so I would have the maximum number of pins to work with. I also went with the ADK version because I'm using an android tablet to program my Arduino board and I'm interested in also exploring Arduino/Android interactivity at some point in the future. Your choice of board might be different.
I wasn't able to find a long skinny box for the hook-up wires so I decided to make my own. Other parts that are required for operation are a battery and some kind of display. I decided on a 9-volt battery which came in a case with a switch and for a screen, I chose the Adafruit TFT display with SD card, mounted on a circuit board. You can use any screen you want, i chose the TFT screen because it was smaller and i wanted access to an SD card. I placed the battery box on the main shelf but decided to mount the TFT screen on the shelves I was going to attach to the inside lid. After trying several different layouts I ended up with the box for the hook-up wires, the battery box, the Arduino Mega board, and the breadboards on the top shelf. The large storage box, 3 large Altoids boxes and six small Altoids tins, which will be mounted on top of the larger tins, would sit in the bottom of the case. They will be attached with velcro, so the can be easily removed. Again, this layout works for the Pelican 1200. If you're case is laid out on one level you might not need shelves. Or, if your component boxes are larger or smaller you're shelves might be smaller or larger. Experiment with your layout and try to maximize your space to best fit the various components and storage boxes into your chosen case.
Step 4: Step 4: Mock-up Continued
With the main shelf laid out, I began on the shelving system and TFT mount for the top lid. If your project won't have shelving mounted in the lid, you can skip this step, however, you should consider where you will mount your display screen and a mounting area for securely mounting servos for experiments that require them.
If you're designing your own case, grab some cardboard and let's get started. I needed shelves for my Altoids boxes and a place to mount the TFT screen, you'll need the same. There's also a problem with using magnets to hold the top and bottom shelves together that needs to be addressed. Any project or experiment that is sensitive to magnetic fields could be thrown off by the magnets. I decided to make an additional shelf for a mini breadboard so I could mount any components sensitive to a magnetic field, as far away from the magnets as possible. If you build your case with magnets I recommend making an isolation shelf as well.
I also decided that I needed someplace to mount servos temporarily, so I decided to modify one shelf so that servos could sit securely on it. Since these little shelves would have to be mounted in the thin lid, they would have to fold up so they could pack up as thin as possible and then fold out securely, when needed. After several cardboard variations, I settled on a version with three fold out shelves for component boxes, a fourth shelf with a cut out for mounting servos, or just a component box, a small shelf for a mini breadboard, and a space to mount the TFT screen. Again, if you're making a custom case, your version may vary.
Step 5: Step 5: Final Measurements and Laser Cutting
With the cardboard version finalized, I could take final measurements to make patterns for cutting the actual parts. I used Inkscape to create my drawings and saved them in .svg format for use in a laser cutter. I've included the .svg files and PDF files with parts names. If you decide to make this project and are using a Pelican 1200 case, you can use the files to print out the parts without modification. However, I recommend printing the files on paper and checking the fit before laser cutting. If you're using a different case, you may be able to modify the parts to fit the measurements of your case.
I bought my acrylic from the plastic supply store and headed to the Los Angeles Build Shop, to use their laser cutter. Now with the material cut, it was time to start putting everything together.
Step 6: Step 6: Construction - Storage Section
I didn't want to risk destroying my parts if I ever had to take apart my kit to change something or fix a mistake I made putting my case together, so I decided to attach thin sheets of lexan to the bottom and lid of the box, and then attach my shelving and supports to that. Using a cardboard template, i cut lexan to fit the top and bottom of the box.
On the lexan sheet that goes in the lid, in the corners and at the center line, top and bottom, a several millimeters from all edges, yet clear off all shelving, drill 5/64" holes. Insert a #2-56 nylon bolt and secure it with a matching nylon nut in each hole you just drilled. These act as attachment points for the laser cut top sheet.
The posts that support the main shelf are made out of the acrylic rod. I inlaid my magnets inside my lexan posts but it's much simpler to simply glue the magnets to the top of the posts. Measure the maximum height of your storage boxes and cut your posts to that size minus the thickness of your magnets. Using super glue, glue the magnets to the top of the lexan posts. On the bottom lexan sheet I laid out my storage boxes and marked out space in each corner for the lexan posts. I then used the acrylic glue to glue the posts, magnets up, to the bottom lexan sheet. Do the same with the bottom lexan sheet for your project. I laid my boxes out again, marked there locations and glued velcro to the lexan sheet and my component boxes. If you're using Altoids tins, use sandpaper to rough up the bottom surface and use super glue to attach the velcro.
Next, we will attach the lexan sheets to the lid and bottom of the case with foam mounting tape. Be sure to put tape directly under the posts on the bottom lexan sheet and as close to the nylon bolts on the top sheet as possible. Clean the surfaces of the case and lexan sheet with rubbing alcohol before applying the tape and allow to dry. Securely attach tape squares to the lexan sheets first then press into the appropriate section of the case.
Step 7: Step 7 - Construction Continued - Main Shelf
Now we'll put together the main shelf. Layout your breadboards, Arduino board, jumper wire box, and battery box and mark the mounting holes for your board. Drill holes at your marks and mount your board using the nylon bolts, nuts, and spacers.
Next we need to put together the jumper wire box. Using the acrylic glue, glue the box parts together first. Remember not to glue the lid to the top of the box. Using velcro, make some straps to secure the lid so it stays closed and then mount it to the main shelf using the laser cut slots. Before gluing though, be sure to check the placement of the wire box to be sure it's not mounted upside down. My breadboards all had mounting tape on them so I simply removed pieces of the backing to attach my breadboards. Do the same or use double sided tape to secure your breadboards. Hint: If you're breadboards come with mounting tape remove only a few small squares of the backing rather than peeling it all off. It will be much easier to fix a misalignment this way. If you are making an isolation shelf, use velcro to attach the mini breadboards to the main shelf.
The final step is to glue washers to the bottom of the main shelf at the location of the support posts. Mark the location of the posts and super glue a washer at each mark and allow to thoroughly dry. Then, next to the washers, but clear of the posts, attach four small rubber feet to the bottom of the main shelf.
Step 8: Step 8 - Construction Continued - Lid Shelving Frame
Your lab is almost finished. Place the shelving frame into the lid and mark the spots where the bolts in the lexan sheet touch the frame. Remove the frame and drill a hole to match your bolts at each mark. Hint: if your acrylic is opaque, place a small dot of paint on the tip of each bolt, and carefully press your frame against them. Be sure your frame is positioned properly.
If you're mounting your display in the lid, do so now. If you're using the Adafruit TFT, find the TFT Mount part and mark and drill your mounting holes. Using the foam mounting tape, attach velcro strips to the back of the mount and the appropriate location on the shelf frame. Making the screen removable takes a few extra steps, but it allows you to change displays easily. I found it well worth the extra steps. Your mileage may vary.
The isolation shelf in my case is in the upper right corner. The hinges for the isolation shelf have to lay flat so I used the 3/4" brass hinges from the hardware store. Glue the hinges to the shelf and support first. Keep in mind that the support is glued to the top side of the hinge with the other side of the hinge attached normally to the frame. See the photos and if in doubt, tape fit first, glue later. Also glue the appropriate piece of velcro to attach your mini breadboard to the shelf, to the top of the isolation shelf. After the glue is dry, glue the shelf hinge to the frame and then line up the support, and glue it's hinge to the frame. Glue a piece of velcro to the underside of the isolation shelf and then using a piece of foam tape, tape a mating piece of velcro to the shelf frame to hold the isolation shelf in place when it's closed.
Step 9: Step 9 - Construction Continued - Shelves
The lid shelving is next. Gather the parts together and separate the shelves and shelf supports. Using the laser cut slots, glue the shelf supports to the shelves. Then attach the side supports and, using the material from one of the cut out slots, glue the little rectangle horizontally to the square side of the support to act as a little foot. Attach the "little foot" to all the shelf supports except for the servo shelf. IMPORTANT NOTE: Use only one side support for each shelf support for the smallest nested shelf or you'll need to notch the hinge for it to fit properly. When the glue has dried, attach the hinges to the shelves using the small hinges for the two nested shelves, and the larger hinges for the other large shelves. Mount the hinges as shown in the photos.
Place the shelves into the frame to check their fit. Use sandpaper to make any adjustments to the fit. Mark the location of the hinges and with a file or sandpaper, create a notch for the barrel of each hinge. Check the fit again, and glue the hinges to the frame. Cut a short piece of tape and attach to the top edge of each shelf to act as a handle for opening the shelves.
When the glue has dried, mount the finished lid shelf into the case by sliding it onto the mounting bolts and securing it with a nut on each bolt.
To keep parts from getting jumbled in the component boxes, create dividers out of card stock to contain the parts. Cut and fold the paper to size and masking tape in place. Organize your component boxes and stock basic components in their most popular values. Apply any final strips of velcro to secure your component boxes. See the photos for examples.
Add components to your component boxes, jumper wires to your wire box, pack up the boxes into the case, and your Electronics Learning Lab/Experiment Kit is finished. Read on though to learn about my last minute additions, my mistakes, and things I'd do differently next time.
Step 11: Final Thoughts - Last Minute Additions
At the last minute I decided to add a stand for the TFT display on the main shelf. This would allow me to remove the main shelf, attach the TFT display and work without being attached to the main case. The stand would be mounted behind my Arduino board on the main shelf and use velcro to hold the TFT mount to the stand. Glue the supports (see the pdf cutting plan for reference) to the main shelf first, then attach the back to the stand supports with the cut out rectangle closer to the top than the main shelf. Attach one side of a velcro strip to the front of the TFT screen mount and under the actual screen, and the other side of the velcro to the back piece of the TFT stand. Make a hole in the velcro so you don't block the rectangular cut out. Now you can mate your TFT display to your main shelf.
Another addition was a small light. Find the part marked "light stick" in the PDF plans. The LED backlight will be attached to one end of the stick while the other end slots into the TFT mount on the main shelf. Solder a 100 ohm resister to one leg of the backlight. Then solder a female jumper wire with one end stripped off to each leg and seal with heat shrink tubing (remember to put the heat shrink tubing on before soldering together the wires). Glue the backlight module to one end of the light stick. On the other end, half an inch from the edge, glue a rectangular scrap of acrylic across the light stick to act as a stop when inserted into the TFT stand. Glue the female end of the jumper wire to the other side of the light stick, just above the stop you just glued on. Then, using two layers of foam mounting tape stacked on top of each other for extra thickness, attach velcro to the jumper side (not the side with the LED module) of the light stick and the small open space under the servo shelf. See the photos for any necessary clarification.
Final Thoughts continued - Mistakes and Changes
The "Super Glue" left a hazy white film where it was used. This scraped off easily but initially looked like a disaster. I couldn't initially find hinges that would fit all of the shelves. The brass hinges from the hardware store were too big for all the shelves and the looked too bulky, so I found the model plane hinges from the hobby shop. Markline (http://www.markline.com) carries an assortment of miniature and 1/2 inch brass hinges. If I was starting over I might use these smaller brass hinges instead of the nylon hinges. I painted the nylon hinges with a Sharpie so they would blend in with the frame better.
I hope you enjoyed my first instructable and will soon be building your own Electronics Learning Lab/Experiment Kit. If you like my Instructable, please vote for me in the Portable Workstation contest.