Intro: Dad-Built Rocket Control Module
So to help with this terrible situation I decided to make something to assist with the imaginative process.
I used mostly parts on hand and scavenged so it only cost me a few bucks for some buttons, the joystick and the aluminum. If you had to buy everything I'm guessing the project would cost $30-40. There is a lot of room for expansion of features and improvements on the design, but here is a good first draft to work from.
- Joystick operated Acceleration Vector Resonator (patent pending) with audio feedback and vector indicator (beepy beeps and blinky lights)
- Launch Status Indicator with turny knob and more blinky lights
- Com-Link packet messaging system (really it just records your voice and plays it back)
- Heads Up Display for targeting and tracking popcorn meteors
Step 1: The "Enclosure"
- 1/4 inch thick Plexiglass sheet, at least 24" x 24" -- bottom plate
- 1/8 inch thick plexiglass sheet, at least 12" x 6" -- top panel
- 1 inch aluminum angle bar -- bottom trim
- heat gun
- straight edges (framing square, metal level, finished shelving, something that won't be harmed by high temps)
- acrylic cutting tool or alternative
- some clamps
For the case I decided to use acrylic. I took two pieces of Plexiglass and used one for the bottom (1/4") and one for the top (1/8").
I cut the 1/8" piece down to about 10" x 6". Cutting acrylic is not as easy as it looks. Careful use of a straight edge and some clamps is advised. If you have a table saw or something that might be a better option. I don't have one.
I wanted to put four bends in the acrylic sheet roughly spaced at 1", 2" and 5 1/2". To do this I clamped down the sheet on top of a straight edged piece of shelving and heated it with a heat gun. I held the gun much closer than you see in the photo and kept it moving evenly right across the intended bend point. Every ten seconds or so I would apply gentle pressure to the free end of the sheet to see if it was flexible yet. It seems good to be patient and just keep heating and pushing slowly to get the desired angle evenly across the sheet. If you see bubbles forming in the acrylic, stop immediately. You've over heated it and it is now producing fumes that are combustible.
This method produced a bend with probably a 1/4 " radius. If you want a tighter angle you may want to use a straight edge on top of the free end of your sheet to push more evenly and closely to your bend point. For the effect I wanted I just pushed along the edge of the sheet with the heel of my hand.
To connect the top and bottom pieces I wanted to make it removable for future enhancements and repairs. I used a piece of aluminum. This is addressed in a later step.
Step 2: The Circuits
This is where you get mad because I don't have schematics or details for my circuitry. I know, I know. But look. I made it up as I went and hacked some of my old projects, so unless you have the same stuff sitting around it wont help you. I will do my best at least to post my code for the picaxe programs. Though I'm sure you fancy kids will be using your fancy Arduinos and such.
The fact is, there are all kind of cool things you can put in there. Here's what I put in it.
$1 analogue joystick from the Habitat Store.
$10 recording module from Radio Shack
A recycled Picaxe 08M project that beeps and lights up one of two LEDs depending on which button is pushed.
A new Picaxe 08M project that progressively lights up three LEDs to represent a launch sequence as a potentiometer is turned.
I wanted to use the two potentiometers in the joystick to add one more level of interactivity, but I ran out of appropriate inputs on the Picaxe and out of time to hammer out a solution. The one thing I would really like to add is rumble effects using a small vibration motor. Maybe next time.
I used a 4 AA battery pack to deliver approximately 6 volts, but this could also run on 9v. The recording module, I believe, can run on anything from about 5 to 12 volts. The Picaxes need 4.5-5 volts regulated. I have both of them running off the same 5v regulator. I wired more than one circuit to the same speaker which ends up making it very noisy when playing back recordings. This is perfect for that space danger effect.
If you happen to have this same joystick the buttons (trigger and thumb) connect the white and blue wires (respectively) to the green. There is some circuitry inside that makes the "Auto" button work. I believe they require a positive (+5v?) charge on the green wire to function. I bypassed this circuit to simplify. Otherwise it is pretty simple inside and you should be able to access the potentiometers the same as the switches. Mine are unused for now.
I wired the trigger and thumb button to operate the "A.V.R." Acceleration Vector Resonator, which is a circuit I recycled from an older project It uses the picaxe to sense one of two button pushes and flashes an led and plays a tone ascending or descending depending on which button is pressed. If you press one button too long there is an explosion noise.
Launch Status Indicator
The potentiometer (knob) operates a second picaxe that simply lights up three leds as you turn the knob. This is the one I would like to add some vibration feedback to in the future.
Com - Link
I wired the recorder module to two sturdy buttons and placed the microphone right beneath them
Step 3: Artwork
In retrospect it would have been wise to 1. Drill all the holes 2. Apply any desired artwork 3. Install wiring... In that order. I was not organized or patient enough to do it that way, so I had to apply my artwork after the fact.
The picture included is my original concept design. I ended up printing it out and cutting it up to rearrange everything to match my final layout.
Don't laugh, but I used clear school glue to stick these graphics right onto the back of the acrylic. Time will tell if this is a good method, but it looks good for now.
Given more time I would like to experiment with painting on the back of the acrylic for different effects. I also plan to print out some "H.U.D." type graphics on transparency sheets and try sticking them on the front window to go along with different "missions."
Step 4: Instalation
Anyhow here's some tips on putting circuitry in Plexiglass.
- Be very careful when drilling. It is easy to crack and chip this stuff.
- Always use backing behind the acrylic when you are drilling
- Pre-drill larger holes using a smaller bit so that your bit doesn't drift
- If you own a drill press (I don't) USE IT!
- If your drill has a clutch with different settings set it as low as you can. This can save you from cracking the acrylic if the bit takes hold. It can also save you from injury or from spinning your workpiece all around your table.
- Also, try running your drill in reverse at high speed. This heats up the material. You can actually melt/scrape your way all the way through using this method, but you might end up with a slightly deformed hole. I found it was good to run in reverse at high speed until a good divot was formed, then switch to forward at slow speed with even pressure decreasing as I approached the end.
My power switch required a rectangular opening. To achieve this I drilled two holes to remove most of the material then used a square file to remove the rest.
I used 22awg solid wiring. It is very strong and you don't really have to worry about breaking it as long as all your solder connections are strong. It isn't as flexible as stranded wire, so you'll really need to push to bend it all in place. As you do so be careful of weaker connections that might break. I installed everything to the top panel so that the bottom plate could be removed completely without destroying anything.
The Joystick has suction cups on the bottom, so I'm letting it remain free to sit naturally in place for now. We'll see how the four-year-old and his two-year-old brother handle that. If they are too rough with it I've thought of drilling right up through the bottom into the plastic housing to secure it to the base.
I may add some velcro to secure the battery pack into place.
If I couldn't figure out how to stick something in I used HOT GLUE. It isn't especially pretty, so I would try to avoid using it in visible places if I were you. Good luck.
Step 5: Closing It All Up
I took a piece of aluminum angle bar and cut it so that I could bend two 90 degree angles into it. This became a trim piece around the bottom edge that I also used to connect the top and bottom pieces.
The top panel is bolted along the front edge of the trim piece. The bottom plate is bolted at the four corners. If I want to adjust or change any of the circuitry, all I have to do is remove the four bottom bolts and slide out the bottom plate.
The great thing about aluminum is that it is very easy to cut and drill. It is actually softer than the Plexiglass. So it is a great material to work with. Just make sure to grind off any burrs and sharp edges.
Step 6: Finish
Once it is all closed up check the whole thing for burs, sharp corners loose fitting components. Sand them down, grind them off or tighten them up.
Clean off any remaining acrylic dust, sticker residue or whoopsy juice (blood).
Record an exciting message from Star Command that explains how to use the controls.
The one video I have of this thing in operation is of a two-year-old. He doesn't quite get it, but still enjoys the noise and lights. My older kids mostly enjoy the recording module.
Version two (if it ever happens) will feature enhanced design graphics, a display (LCD? 7-segment?). More buttons. More sounds. Vibration feedback. More joystick control. RFID? A working H.U.D.? A phones jack. Got any more ideas?