This instructable assumes you know the basics of building and launching model rockets. It is easy to learn and get started. I've skipped the steps of building the rocket as those steps will follow the instructions included with the rocket aside from the rocket parts involved with this instructable.
**Important - Substitutions can be made for the model rocket being used or the keychain camera model, but doing so may alter these steps. If you change anything, be prepared to perform slightly different modifications to get your camera to fit properly. Research never hurts either.**
Model Rocket - For this Instructable I used an Estes Reflector since it has a payload bay. I also did extensive research to make sure the payload bay diameter [1.33 in. (34 mm)] was wide enough to hold the keychain camera [~32 mm wide without case].
Note: I upgraded my parachute to a larger spare 18" chute we had laying around to slow the rocket descent with the camera on board. This increased the time it takes for the rocket to come down and could be problematic in a small launch area if wind is present. The stock parachute should be fine with camera on board.
Keychain Camera - Most keychain cameras will fit as you will have to remove the case. This guy's site has everything you need to know about the various models and is a must read: http://www.chucklohr.com/808/ For my purposes I selected the #11 808 ($30) model since it has true 720p HD video. I purchased it from eBay. Some camera models "claim" to have 720p or better HD video but they actually convert lower quality video up to HD video, so do your research on other models. Also be mindful of the frame rate. The #11 has a 30 fps (frames per second) frame rate which isn't bad for such a small HD camera. Some cameras only do 15 fps which I would find unacceptable for something as fast as a rocket launch. Look for 30 fps or better.
Video Editing Software - There are plenty of free options on the internet. I used Windows Movie Maker.
Memory Card - Micro SD. Class 4 or better to handle the volume of HD video data. I used 4gb capacity. A USB card reader will make your life easier as well.
Foam Ear plugs - A pair or more. These are for securing the camera in the payload bay, not for your ears!
Tools for constructing the rocket (consult your manual for complete list):
-Glue (Elmers or other strong general purpose glue)
-Sandpaper, preferably a sanding block
-Spray Paint - however you wish to paint your rocket. I used flat black and metallic gold.
-Pinstriping tape - optional but makes cleaner, more uniform paint stripes than masking tape.
Tools for modifying the rocket in this instructable:
-A saw. I used a hacksaw
-Glue (Elmers or other strong general purpose glue)
-Sandpaper, preferably a sanding block
-Small, sharp kitchen knife
-Dremel - to cut a nice hole for the camera lens. An Xacto knife could probably be used instead if a Dremel is not available.
-Pen or pencil
-Small phillips head screw driver, like the type for eye glasses.
Videos of my launches:
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Step 1: Notes on Rocket Selection
The rocket I used is the Estes Reflector. I selected this rocket for several reasons:
1. It has a payload bay for carrying objects. This is perfect for putting a keychain camera inside and carrying it safely. You cannot put a camera inside the body of a rocket, as this space is needed for the parachute and recovery wadding to protect the parachute. The engine's discharge to deploy the parachute travels through the body, so it needs to remain clear and unobstructed. The camera would get fried from the discharge.
2. The payload bay on the Reflector has a diameter capable of carrying the keychain camera. This is important because we shouldn't have parts of the camera (other than the lens) protruding outside the rocket. Several other model rockets with payload bays have a smaller diameter which would not fit the camera.
3. The Reflector's parts are made of wood and cardboard which makes them very easy to modify.
Other model rockets with payload bays may yield different results. Do research if you decide to use something other than the Estes Reflector. Other model rockets may use plastic parts or require different measurements and modifications for the camera to fit.
Step 2: Build Your Rocket (mostly)
This tutorial is made under the assumption you can build a model rocket. Most kits are not difficult. The Estes Reflector is good for beginners as it is Skill Level 1.
Following the instructions that came with your rocket, build the rocket but leave all the pieces of the payload bay untouched and unfinished. These pieces include: nose cone (top), payload bay tube, and payload bay base (bottom). These parts will need to be modified to accommodate the keychain camera first. Do not attach the eye screw to the base of the payload bay. I attached the eye screw when I built my rocket, but it will save you some trouble if you attach the eye screw after the modifications are complete. Also, do not paint anything yet.
Step 3: Disassemble the Keychain Camera
We don't need the keychain case that the camera comes in. It adds unnecessary size and weight.
1. Using a small screwdriver, remove the screws on the case.
2. Pry the case apart and remove both halves of the case and the plastic buttons. Save these if you ever want to use the camera with the case. You may wish to tape the camera in the case to the side of a rocket to record downward facing rocket flight videos.
The camera sensor and lens may be glued to the circuit board as mine was. If so:
3. Use an Xacto knife, or a small sharp kitchen knife to cut through the glue. It is the same glue used in glue guns and is relatively soft. It will take some effort and patience to cut through the glue to separate the lens/sensor assembly.
For this step, be VERY VERY VERYcareful not to break or cut into the ribbon cable that connects the camera to the circuit board. Damaging this ribbon cable will basically ruin the camera, and these cables cannot be easily repaired as conventional soldering melts them. *I'm not responsible if you damage your camera*
Once you are finished, you should have a bare camera with a sensor/lens assembly that is now movable.
Step 4: Measuring for the Cuts
This will require some measuring and judgement to get a good fit. We will be working with three pieces from the rocket kit in the next few steps. The nose cone is as it sounds, the wood nose of the rocket. The payload bay tube is the cardboard tube to contain the payload. The payload bay base is the wood piece that joins the payload bay to the body of the rocket. One end has a larger diameter than the other end.
The wood nose cone and wood payload bay base take up a lot of space in the payload bay tube when everything is put together. This is not enough space for the camera to fit. We will cut some the wood from each piece to allow space for the camera inside the payload bay tube.
Mark the payload bay base and nose cone.
I placed the pieces together beside each other and positioned them as if they were assembled to get an idea of the space I need to clear. I placed the camera on top of the parts, about 1/2 inch from where the payload bay tube would rest on the payload bay base. Since the payload bay base will be glued securely into place, I decided to cut the most wood off of this piece. Using a pen, I marked a dot 1/2 inch from where the tube rests against the base. This means there will be 1/2 inch of wood left to secure the tube to the base. I then marked on the nose cone just above where the camera microphone is (silver cylinder) at approximately 11/16" from where the tube rests against the nose cone.
By sliding the payload tube down to the mark I made on the payload bay base, I then used the tube to draw a line all the way around the wood to use as a cutting guide.
Step 5: Modifying the Payload Bay Base
Cut the payload bay base
The wood is soft Balsa, so it should cut easily with most saws. Just be careful not to apply a lot of pressure when holding or cutting as you can compress or dent the wood. Hold the wood on the side of the line with the most wood. Place the saw blade on the line and pull towards yourself to get a groove started. Do not apply much pressure into the cut, the weight of the saw should be enough to cut the wood.
Using your guide line to keep your cut level, continue to saw through the wood. Rotate the base around so you cut around the outside first and keep your eye on the guide line to maintain your straight line. Continue cutting evenly all around towards the center. When you are almost done, cut through the center.
You will probably want to give your newly cut base a sanding to smooth it down, make it level, and to remove any loose wood bits.
Step 6: Modifying the Nose Cone
The nose cone must be removable to place the camera inside each time you use it. It cannot be glued and must rely on friction to stay sealed during flight. This is why we will leave more wood on the nose cone after we cut it for the inside of the payload bay tube.
1. Use the same technique that was used on the payload base to draw a line around the nose cone wood where the measurement mark was made.
2. Use the same technique as before to saw the nose cone.
3. Sand the nose cone's cut surface
At this point, we should have enough space inside the payload bay to fit the camera. Place the payload base inside the payload tube. Place the camera inside the bay with the camera side at the top. Place the nose cone inside the payload tube. The base and the nose cone should slide in as far as they can, without being obstructed by the camera. You may need to make sure the lens is not blocking the nose cone and is positioned beside the camera circuit board in the tube. If there is not enough room, make note of how far the NOSE CONE sticks out, and cut or sand off that length of wood from the nose cone.
Step 7: Cut Hole for Camera Lens
The payload bay on the Estes Reflector is not transparent so a hole must be cut in the side for the lens to poke through. Even if the payload bay tube was transparent, it would be wise to cut a hole for the lens to eliminate any distortion or other issues. This hole also serves to hold the camera steady during flight.
1. With the payload base inserted in the payload bay tube, gauge where the lens hole should go.
A couple of things to keep in mind for the hole placement:
-Once the lens is in the hole, the lens/sensor cannot contact the nose cone. Make sure the hole is low enough for the nose cone to be fully inserted once the lens is in place.
-The hole must also be within reach of the lens ribbon cable. Placing the hole too low will put the hole out of reach of the short ribbon cable.
2. Using a pen or pencil, place a dot where the center of the lens hole should be on the outside of the tube. The center of my hole was marked at 1 3/16" from the top of the tube but may vary depending on where your payload base was cut.
3. Take the camera out of the tube. Place the lens on the dot and center it on the dot. Using the pen, trace around the lens to create a circle in the shape of the lens.
4. If you have a Dremel, use a cone or parabolic shaped grinding stone to grind/sand a hole using the dot as a starting point. Use the circle as a guide to keep the hole centered. If you do not have a Dremel, use an Xacto knife to cut out the hole WITHIN the lens outline you traced.
5. Push the spinning grinder into the tube to expand the hole until you near the size of the circular outline that was traced. The final diameter is approximately 1/4".
6. When the size of the hole approaches the outline you traced, check to see if the lens can be pushed through the hole. The goal is for the lens to pass easily through the hole, but not be too loose that the lens vibrates or too tight that it won't enter easily.
7. Use an Xacto knife to clean up any loose cardboard left behind on the opening from the grinding process.
8. Check the final fit. Place the payload bay base into the tube, place the camera in the tube, maneuver the camera lens into the hole so it protrudes slightly from the tube, and place the nose cone on. Make any necessary adjustments for fit.
Step 8: Finish Payload Bay
1. Glue the payload bay base into the payload tube.
--Glue it well. We have removed a lot of the wood and it will need a secure bond.
--Make sure the base is glued into the correct end of the payload tube, since the hole for the lens will not be centered along the length of the tube!!
2. Make sure the nose cone has a very snug fit in the payload tube, but is still removable. If necessary, wrap the wood section that is inserted into the payload tube with masking tape until a good fit is achieved.
--This is important because once the rocket is launched and the parachute is deployed, the nose cone will be pointing DOWN and it will be the only thing holding the camera in the payload bay!! The nose cone should fit tightly, yet it must still be removable by hand without damaging the rocket.
Step 9: Finish Building Your Rocket
Now that the payload bay is modified to carry the camera, finish any remaining steps for building your rocket, such as:
-putting the eye screw into the payload bay base
-attaching shock cord and parachute to eye screw
Step 10: Prepping Camera for Launch
1. Fully charge the camera battery
2. Insert Micro SD card into camera
3. Test camera to make sure it works and view the test videos on a computer. Familiarize yourself with the buttons and function indicator lights.
You'll want to practice inserting the camera into the rocket before launch day. It can be tricky and you'll be recording video the whole time you install the camera when you film a launch.
1. Perform all prep on the rocket necessary for launch (recovery wadding, load parachute, load engine, insert igniter, etc)
2. Turn on camera
3. Start the recording
4. Place camera inside payload bay tube
5. Maneuver the lens to point through the lens hole of the payload bay tube
6. While lens is in place, tightly compress 1 ear plug as you would when inserting it into your ear and insert it vertically between the payload bay tube wall and the camera circuit board on the side of the circuit board away from the camera lens. Let it expand.
7. Compress 1 more ear plug and insert it vertically as best you can between back of camera lens/sensor and camera circuit board. Let it expand.
8. Use more earplugs if needed to hold the camera lens and circuit board in place.
9. Once camera is secured with ear plugs, insert the nose cone into payload bay tube.
You are recording and ready for launch!
Step 11: Post Launch
Now that you've launched your rocket and recorded video, you'll want to make your results presentable. As you will notice once you view your videos on a computer, the launch part of the video appears up-side down, while the video after parachute deployment is right side up. This is due to the different orientation of the camera and the payload bay during lift off and after parachute deployment. There is also a lot of unnecessary footage that was recorded during camera loading and unloading from the payload bay.
My videos appear right side up the entire time and are relatively brief. How did I do that? Simple and free video editing software such as Windows Movie Maker (what I used) can fix this video orientation issue, will allow editing, and are fairly easy to learn. With software like this, you can split your video into two sections and rotate the section that appears up-side down. If done properly, it gives the illusion that the camera was right side up the entire time! Nobody will know the difference and anyone who is familiar with rockets might scratch their heads wondering how you did it.
Thanks for reading and let me know if you have any questions, comments or suggestions. Enjoy!