Adapting Inexpensive Cameras to Rockets and Kites

 The CVS motorized 35mm film camera. 
    This $15 camera takes 27 pictures very fast.  At 5.6 oz., it weighs more
than the CVS digital cameras, bad pictures cannot be deleted and you cannot
see the pictures until they're processed.  It uses 5" body tube, and a 29mm
(1 & 1/8") G40-4 motor is required.
   By using 12-exposure film rolls, several flights can be filmed in one day.
The camera uses a standard 35mm film cartridge.  It requires two AAA cells,
and rewinds at the end of the roll.  Putting in a fresh roll winds the leader
onto the transport drum and zeroes the counter.  But be aware that the leader
must be put in just right for this feature to work.
   For continuous shooting from a rocket, a common model servo was modified to
push the shutter button repeatedly.  Only the motor and gearbox are used.
To modify it, a limit tooth on the output gear must be cut off.
The pin points to where the limit tooth was.
   Foil going to the ground side of the motor (black wire) was left intact,
but the positive side was isolated from the rest of the circuit.  This is done
using a sharp hobby knife to cut the foil.
Foil cuts, with motor wires soldered on.
The feedback pot is on the left.
  The feedback pot can be cut off or the black plastic shaft can be sawed off.
The pot was cut off.
  Our servo was a Futaba S3003 that we had on hand. The servo, switch, two AA
batteries and battery holder add 3 oz. to the weight.  A G motor adds 4.3 oz.
   This camera can take pictures faster than the digitals, about one every 2
seconds. The servo is down at the camera level and as far over as possible for
balance. The fins extend below the bottom to get the aerodynamic center as low
as possible. The servo batteries are as high as possible and on the same side
as the servo to get the center of gravity up and the longitudinal weight
distribution right. The two body tubes are permanently joined at the central
disk.  The launch switch is a common roller-lever microswitch.
 The bottom section before epoxying. 
   The fins are epoxied to the fin supports.  The white plastic tube is the
chute cable guide. The motor tube has not been epoxied in at this point. The
disk shown will be epoxied to the top of the fin supports. The motor tube and
chute cable guide will be epoxied in and the upper body tube will be epoxied
to the lower body tube and to the central disk.
The servo mechanics and camera.
   The toggle switch, servo, two chute-cable collars, motor tube, motor
retainer and shutter lever, with the camera secured in place.  A plywood door
will be over the servo and shutter lever.
NOTE: Be sure to open the LENS COVER before every flight!
   The servo batteries are up at the top, the toggle switch is on the left at
the bottom and the launch switch is at the right just above the launch lug.
All components and wiring are accessible for servicing if need be.  This
rocket weighs 2 lbs. without rocket motor and chute.
   This design has most of the weight at the very bottom.  A rocket should
have the center of gravity (balance point) about one-third of the way up from
the aerodynamic center, which is usually at the top of the fins for thin body
tubes. If it's too high, the rocket will weathervane into the wind too much
when the motor is thrusting.  Some degree of low stability can be minimized
with a very long guide rod, such as 8 to 10 feet.  If the center of gravity is
too close to the aerodynamic center, flight will be erratic!
   Very heavy rockets can be tested on a windy day by suspending them by rope
from a 2 x 4 laid on top of two stepladders or other supports of equal height.
  Tying a string around the center of gravity so that the rocket balances
and then swinging it in a circle overhead should cause it to always point in
the direction it's going, even if extra weight has to be added near the top.
It MUST be stable!
   Most camera rockets put the camera in the upper part of the rocket and use
a mirror to view the ground below, which reverses the image.  The mirror
should be a "first-surface" type, meaning the reflective aluminum is on the
front, not the back, to avoid double images.  To un-reverse the images, they
can be viewed in a mirror, they can be flipped over digitally in software or
the film negatives can be flipped over during processing by special request.
   This rocket was designed to keep the camcorder high and out of harm's way
during motor burn and landing.  The tapered tail section and use of three
fins allows the lens to be zoomed full wide-angle and have an unobstructed
view. The fins are spaced such that the lens is centered between two of them.
The camera must not have image stabilization.
 The Target and Ritz Camera pocket camcorder. 
   This is very similar to CVS and Ritz one-time-use camcorders, except it
records 30 minutes of video, not 20, plugs directly into the inputs of a TV
or VCR and has a swing-out USB connector. So you can watch the videos on your
TV and tape them on your VCR.   Or you can download the videos into your
computer and save the clips on your hard drive and/or burn them to a CD. The
video is in .WMV format so clips can be emailed or posted to a web site. The
software is inside the unit itelf, so just plug it into any computer with
Windows XP. It weighs just 5 oz. and shuts down after two minutes if not
recording before then.  The lens zooms, and you can view any video clip.
 The base unit. 
   This is the camera platform with the lens hole, aeroform sides, aluminum
chute-eject gas tube, motor tube and fin supports.
 The internal mechanism. 
   The horizontal shaft has a fitting that pushes the On/Off button when the
shaft end is twisted.  The white plastic tube is the record pushrod guide.
The Record button is red. The spring pulls the record pushrod down to start
video recording when the launch key is pulled out.  The chute pull string is
clamped in the alligator clip and will pull the record pushrod up briefly
when the chute is depoyed. The chute string will then pull out of the gator
clip and the Record button will be pushed again to end that video clip.  The
camcorder will then turn itself off after two minutes. If the parachuting
portion of the flight is to be filmed, do not use the chute pull string.
   The chute pull string is through the guide at the top and held in the
alligator clip on the Record pushrod at the left.  Total weight is 1 & 3/4 lb.
minus the motor.  A G40-4 motor adds 4.3 oz.
 Detail of the camera side. 
   The launch key holds up the alligator clip fitting on the Record pushrod.
The chute pull string is in the alligator clip.  The On/Off shaft end is the
short wire on the side of the aeroform.  The string loop is the keeper for
the camera wedge.
 A single frame from the first video. 
   The yellow and red thing is the chute.  The car is under the smoke.
The CVS Single-Use Camcorder.
   These $30 camcorders store 20 minutes of video. At the end of that
time, they are returned to CVS and you get a DVD back ($13).  You can only
view the last video taken and delete it if you wish. The lens does not zoom.
Base plywood.
   On opposite sides of the motor tube are the holes for the chute anchor
cable. The red circles are holes for the camera clamp.  Black is the hole for
the On/Off pushrod. Blue is the hole for the Record pushrod.  The small hole
is to look to be sure that the camcorder comes on before launch.
Inside the body.
   This shows the four fin supports. The display is seen in the small hole.
The white plastic tubes are guides for the On/Off and Record pushrods.
The camera end.
   This shows the camera secured in place.  The wing nut holds the motor in.
   Far left is the On/Off pushrod wire. The oblong hole is to see the display.
On the right is the launch lever, above the launch lug.  The upper body tube
is in place.  This rocket weighs 2 & 1/4 lbs. without a 1/4-lb. G40-4 motor.
The main sections.
   At left is the upper body tube and hinged nose cone. On the right is the
chute tube.
The launch lever and Record pivot arm (in slot).
   When the guide rod drops away upon launch, the Record pushrod will start
the video segment. When the rocket is recovered, the pivot arm is moved to
the right to stop the video segment. Then the On/Off pushrod is moved down.
 The flame guard.
   This is heavy fiberglass cloth with a rubber cement border.  Attach it to
the shock cable with a safety pin. Quest or Estes chute wadding is put inside
the guard so no chute eject blast can damage the chute fabric or shrouds.
 The flameproof shock cable.
   Bicycle shift cable with 1/16" ferrules can take any chute-eject charge.