Apogee Midge User manual

Brand: Apogee

Model: Midge

Type: User manual

Page 1

Colorado Springs, Colorado USA

web site: www.ApogeeRockets.com

The Midge rocket is another ne product from:

Kit #05045

Midge

(A Two-Stage Payload Altitude Rocket)

P/N Description Qty

Parts List

13000 Coupler 18mm X 0.35” (Red) 2

10055 Engine Mount Tube AT-13/8.0” 1

10082 Payload Tube AT-18/5.0” 1

12350 CBD-18mm Sheet 1

12999 Coupler AC-18C (Brown NAR Payload) 1

13012 Coupler AC-13 1

13020 CR 10/13 (green) Engine Block 1

13029 CR 13/18 (blue) Centering Ring 1

13051 1/8” Launch Lug 1” Long 1

15552 Midge Fins 1/16” X 3” X 3” 1

19012 13-to-18mm Ogive Transition (VF) 1

19207 Vac Form Nose Cone VFNC-18 1

29519 100# Kevlar X 6 ft 1

29111 8” Hexagon Orange Plastic Parachute (1/pk) 1

31013 Midge Instruction Sheet A 1

31014 Midge Instruction Sheet B 1

35535 13mm 3-Fin Alignment Guide 1

47122 Clear Plastic Bag 6x14x2mil 1

Other Tools and Materials Needed

Pencil

Hobby knife

Wood glue

Super glue (thick viscosity)

Plastic packaging tape

Paint supplies (spray paint, brushes, etc.)

Wood sealer

Sandpaper (220 and 400 grit)

Wood dowel for spreading glue inside tubes

Sand (28 grams - not included)

p/n 31013

Shock Cord Anchor Pattern

The Midge is a two-stage payload altitude rocket

designed specically for NAR competitions. Use it in

single stage conguration in the A-altitude competition,

or two-stage in the “B-altitude” event (because two A-

size engines added together is equivalent to the power

of a “B” rocket motor).

The dual-diameter rocket is sized to carry the NAR

Standard Payload and an altimeter that t into an

18mm payload tube. With its custom vacuum-formed

transition section the Midge then reduces down to a

13mm motor at the bottom to decrease the weight and

lower the drag. This rocket also comes with a cardstock

n alignment guide to assure that the ns are perfectly

straight and evenly spaced around the rocket. This low-

ers the drag, and allows the rocket to y to new record-

setting altitudes.

Skill Level 3: Average Skills Needed

MIDGE

Page 2

Assemble The Midge Rocket

1. Remove the parts for the n alignment

xture from the cardboard sheet. Dry as-

semble the parts as shown. Make sure the

tabs on the cross pieces protrude through

the side plates. Apply a bead of wood glue

over the tabs on both sides of the tool. Set

the piece aside to allow the glue to dry.

2. Separate the tubes. Sand off the little

nubs of paper on the ends of the tubes using

medium grit sandpaper.

3. Glue one of the red paper tube cou-

plers into the base (as far as it can go) of

the nose cone using thick viscosity CyA glue

(also called super glue). Set it aside to allow

the glue to harden.

4. Taking the point of your hobby knife,

carefully drill a small hole into the base of

the shoulder on the vacuum form plastic

transition. The hole only needs to be slightly

larger than the diameter of the yellow shock

cord.

5. Glue the remaining red paper tube

coupler into the front of the plastic transition

as far as it will go using thick viscosity CyA

glue. Set it aside to allow the glue to harden.

Tip: Paint the inside of the transition black

to block sunlight from affecting the altimeter.

Why? Because the pressure sensor is often

affected by bright light.

6. This step for FireFly Altimeter - If

using the MicroPeak, skip to step 9. Mark

a pencil line on the brown payload tube 1.4

inches (35.5mm) from one end. It will be

used to push in the blue centering ring.

Glue

(both sides)

1.4 inch (3.5 cm)

For FireFly

Altimeter

Page 3

7. Place a small amount of wood glue

on the tip of a wood dowel. Smear the glue

around the inside perimeter of the white pay-

load tube, 1.25 inches (3 cm) deep on the

end of the tube with the small holes.

8. Using the brown tube from step 6,

push the blue ring into the glue from step 7.

The 1.4-inch (3.5cm) line should be even

with the end of the payload tube. Remove

the brown tube immediately and wipe out

any excess wood glue from inside the

payload tube (on both sides of the blue ring)

and off the brown tube. Allow the glue to dry.

Continue on to Step 12.

9. When using the MicroPeak altim-

eter, follow the next three steps.

Since the MicroPeak is a smaller altim-

eter, it will t into the transition of the rocket.

Therefore the payload tube can be made

shorter so the rocket weighs less and ies

higher.

Using a hobby knife, cut the payload at

the eteched line on the opposite end of the

holes. Using sandpaper and sanding block,

make sure the edge is smooth and at.

10. Place a small amount of wood glue

on the tip of a wood dowel. Smear the glue

around the inside perimeter of the tube, just

in front in the small holes.

11. Using the brown tube push the blue

ring into the glue from step 10. The blue ring

should be just in front of the small holes, so

they are not blocked. Remove the brown

tube immediately and wipe out any excess

wood glue from inside the payload tube (on

both sides of the blue ring) and off the brown

tube. Allow the glue to dry.

1.25 inch (3cm)

For FireFly

Altimeter

For FireFly

Altimeter

Brown tube

For MicroPeak

Altimeter Only!

For MicroPeak

Altimeter Only!

Do not block vent holes

For MicroPeak

Altimeter Only!

p/n 31014

1.4 inch (3.5 cm)

Page 4

12. Fine sand the balsa wood laser-cut

sheets using 200 and then 400 grit sand-

paper before removing the ns. Carefully

remove all the pieces from the sheet by free-

ing the edges with a sharp hobby knife.

For higher ights, round the edges of the

ns with sandpaper – or better yet – sand an

airfoil shape into them. Test t the ns into

the slots on the n alignment xture. If they

are too tight, you will need to sand down the

thickness slightly.

13. Sealing the surface of the balsa with

sanding sealer reduces the skin friction drag

on the rocket, allowing it to y higher. It also

improves the rocket’s appearance. Apply the

sealer with a paintbrush. When dry, sand it

with 400 grit sandpaper. Repeat the proce-

dure until the balsa grain is lled and the ns

look and feel smooth.

14. Slide the n alignment xture onto the

long body tube over the end that is etched

with the n lines. Test t the smaller set of

ns into the xture. Position the trailing edge

of the ns on the tick-marks that are etched

onto the n lines. When you know how the

ns are attached, you can remove them from

the n alignment xture and apply wood glue

to the root edge and then put them back into

the n alignment xture. Allow the glue time

to dry before removing the n xture.

15. Repeat the process of attaching the

ns, but this time use the larger ns and at-

tach them to the short booster stage tube.

OPTIONAL: For competition ights, it is

recommended that you launch the rocket

from a piston launcher or from a launch

tower. But if you do not have one, you’ll

need to use a standard launch rod. In that

case, install the launch lug as follows.

16. Glue the balsa wood standoff to the

front end of the body tube in the position

marked on the tube. When the glue is dry,

glue the launch lug to the stand-off using

wood glue. Make sure the lug is parallel to

the length of body tube.

17. Add wood glue llets to the ns and

the launch lug (if added). Lay the rocket

horizontally to let the glue dry.

Smaller

ns

Sustainer (upper stage)

Larger ns used

in booster stage

Fin location

line

Fin location

line

Page 5

18. OPTIONAL: Glue the green engine

block into the long sustainer tube, 1-1/4

inches (3.2cm) deep. To save weight, you

can leave out this piece.

19. Cut out the shock cord anchor from

the front of instruction sheet. Spread glue

on one side. Take the free end of the shock

cord and lay it diagonally across the paper.

Fold it twice on the marked lines, and then

curl it slightly so it will t into the long tube

with the ns.

20. Glue the shock cord mount into the

front of the long tube with the ns on it.

Make sure it is deep enough to allow the

shoulder of the payload section to be in-

serted into the tube.

21. Thread the free end of the yellow

shock cord through the hole in the base of

the transition. Tie a loop in the front end.

This will give you a place to tie the altimeter

to the rocket in case the model separates

in ight. Tie a big enough knot about 1.5

inches (3.8 cm) from the tip of the loop in

the cord so it can’t be pulled out through the

hole. Pull the cord so the knot is at the base

of the transition. Using thick CyA adhesive,

glue the knot inside the base of the plastic

transition.

22. Tie a loop knot into the shock cord

as close to the base of the transition as you

can. This will be the loop used to attach the

parachute.

23. Assemble the NAR Payload by gluing

a cardstock bulkhead disk ush with the end

of the brown tube using wood glue. Allow

the glue to dry. Fill the tube with ne sand

(not included) so the entire payload weighs

28.0 grams. Remember to include the mass

of the second bulkhead when weighing it.

Shake the tube to settle the sand. Then glue

the second disk on the open end and allow

it to dry.

1-1/4” (3.2cm)

1.0” (2.5cm) minimum

Approx. 1.5” (3.8cm)

Pull tight

Page 6

24. Place one reinforcement ring on each

of the corners of the parachute canopy.

Take a sharp pencil or knife and poke a hole

through the plastic in the center of each ring.

25. Cut the shroud lines to make a total

of three lines of equal length. Then pull each

parachute line end through a parachute re-

inforcement ring and tie using two overhand

knots. Repeat for all the corners as shown.

26. Holding the parachute at the center of

its top, pull the lines together to even up the

ends. Thread the three looped lines through

the loop in the shock cord. Next, take the top

of the parachute and pull it through all three

string loops at the same time. Finally, pull on

the strings to tighten the knot. This securely

attaches the parachute to the rocket.

27. Fold the parachute and insert it into

the rocket along with the shock cord.

28.Temporarily assemble the rocket. You

can use the red tube coupler to join the two

stages together. Roll a piece of paper and

insert it into the back of the rocket to hold

the model while you paint it. We recommend

a uorescent color like orange, pink or yel-

low to make it easier to nd the rocket after

touchdown. Allow the paint time to dry.

Congratulations! Your Midge rocket is

now complete.

Launch Supplies Needed

To launch your rocket you will need the

following supplies:

• A model rocket launching system

• Flame resistant recovery wadding

• Recommended Rocket Engines:

See the motor matrix to the right.

red coupler

Midge Rocket Recommended Motors

Engine Manufacturer Altitude (ft) Altitude (m)

A10-3T Estes 259 79

A10-0T / A3-4T Estes 671 204

A10-0T / A10-3T Estes 637 194

Page 7

Tape

Motor Retention for when the

sustainer is own with the

booster stage

Altimeter

NAR Payload

String - tie altimeter

to transition

Tape

Do not cover vent holes

Rocket Preight

A. Crumple and insert one-half of a sheet

of recovery wadding into the body tube.

B. Fold that parachute and insert it into

the tube with the shock cord. Then insert the

plastic transition section onto the tube.

C. Tie a string from the loop inside the

transition to the altimeter for extra security in

case the rocket comes down in two separate

pieces. Turn on the altimeter and insert it

into the rear of the payload tube (closest to

the vent holes), and then insert the shoulder

of the transition too. Place the NAR payload

into the forward end of the payload bay, and

then insert the nose on top.

D. Wrap tape around the perimeter over

the two ends of the payload tube as shown.

Make sure not to cover the vent holes for the

altimeter.

E. If ying the sustainer alone as a single

stage, it is preferable to hold the engine in

the tube by wrapping tape about the portion

of the motor that extends out the rear of the

tube as shown.

F. If you’re ying the Midge as a two-

stage rocket, the motor in the top stage is

friction tted into the tube.

G. For the booster stage the motor is

inserted so the motor extends out the back

3/8” (0.9 cm) and then held in place by wrap-

ping tape around the perimeter of the motor

and the tube.

Motor Retention for when

the sustainer is own alone

(without the booster stage)

Tape

Booster Stage

Tape

A&B

3/8” (0.9 cm)

Page 8

H. The two stages are joined together by

inserting the upper stage motor (the portion

that sticks out) into the front of the booster

stage.

I. Insert and secure the engine igniter as

directed on the package the engines came

with.

Countdown and Launch Procedure

Fly your rocket on a large eld that isn’t

near any power lines, trees, or low ying

aircraft. The larger the eld, the greater

your chances of recovering your rocket. The

launch area around the pad must be free of

dry weeds and brown grass. Launch only

during calm weather with very little or no

wind and good visibility.

10. Remove the safety key from the

launch controller.

9. Slide the launch lugs over the launch

rod to place the rocket on the pad. The

rocket should slide freely over the rod.

8. Attach the micro-clips to the igniter.

The clips must not touch each other or the

metal blast deector.

7. Stand back from your rocket as far as

the launch wire allows (at least 5 meters - 15

feet).

6. Insert the safety key to arm the launch

system. The light (or buzzer) on the control-

ler should come on.

Give a loud countdown 5 ... 4 ... 3 ... 2 ...

1 ... LAUNCH!

Push and hold the the button until the en-

gine ignites. Then remove the safety key and

place the safety cap on the launch rod.

*National Association of Rocketry

**Kevlar

is a brand name of E.I. DuPont for their selection of aramid bers. Only DuPont makes Kevlar

Always follow the NAR* Model Rocket Safety Code when launching

model rockets.

Misre Procedure

Occasionally the igniter will burn, but the motor will fail to ignite. If this

happens, the cause is that the pyrogen on the igniter was not in contact

with the engines propellant. When an ignition failure occurs, remove the

safety key from the launch controller and wait 60 seconds before ap-

proaching the rocket. Remove the old igniter from the engine and install

a new one. Make sure that the igniter is insert fully into the engine and

touches the propellant. Secure the igniter as directed on the engine pack-

age and repeat the countdown and launch procedure.

Apogee Midge User manual

Apogee Midge User manual

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