| Manufacturer: | Scratch |
(Contributed - by Norman Dziedzic)
As you may have seen in Descon 6, I like Odd
Rockets. Since Halloween was smack dab in the middle of Descon 7, I had to enter the Jack-o-Lance Beta. This
model was originally named, "The Pumpkin Stick" but I think the New name has a little more Rocketry Flare.
The main oddity on this rocket is the pumpkins stacked on the body tube. These are a standard haloween decoration
called a Pumpkin Candy Cup.
The balance point on the Jack-o-Lance Beta is about 2/3 of the way up on the 4th pumpkin
(countin from the bottom) or approximately 10.25" up from the aft end of the body. This balance point was achieved
with no nose weight required and proves stable for both 18mm C motors and 24mm D motors.
The Jack-o-Lance Beta
As you may have seen in Descon 6, I like Odd
Rockets. Since Halloween was smack dab in the middle of Descon 7, I had to enter the Jack-o-Lance Beta. This
model was originally named, "The Pumpkin Stick" but I think the New name has a little more Rocketry Flare.
The main oddity on this rocket is the pumpkins stacked on the body tube. These are a standard haloween decoration
called a Pumpkin Candy Cup.
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Height:
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28.25" |
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Weight (no motor):
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156 g (5.5 oz) |
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Body Size:
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BT-60 |
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Number of Fins:
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4 |
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Fin Span:
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10" |
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Recovery:
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Parachute |
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Motor Mount:
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24mm |
Parts List
- (1) BT-60 x 16" long
- (1) BT-60 x 6.75" long
- (1) BT-60 Tube Coupler
- (1) 24mm Motor Mount Kit
- (1) 3" wide x 16" long x 1/8" thick balsa sheet for fins
- Cut to (4) 4" long pieces (see fin pattern for grain direction)
- (1) 1/4" wide x 16" long x 1/8" thick spruce for fin ends
- Cut to (4) 4" long pieces
- (1) PNC-60 Plastic Nose Cone
- (2) 1/8" x 1" long launch lugs
- (10) plastic Pumpkin Candy Cups
- (1) Shock cord material of choice
- (1) Parachute of Choice
Construction
- Assemble the 24mm motor mount per the instructions (allow to dry fully).
- Glue the BT-60 coupler into the end of the short piece of BT-60 body tube leaving half of the coupler exposed (allow to dry fully).
- Glue the 24mm motor mount into the end of the short piece of BT-60 opposite the coupler. Make the aft end of the motor mount tube flush with the end of the BT-60 (allow to dry fully).
- Glue the long piece of BT-60 body tube to the short tube/coupler assembly using the coupler to align the two body tubes (allow to dry fully).
- Mark the aft 3" of body tube at 4 places equally spaced around the tube. One method to do this is as follows:
- Wrap a piece of paper around the tube and make a mark on the paper where it overlaps itself.
- Remove the paper from the tube and fold it so the outer edge of the paper meets the mark made above.
- Fold again so that the crease made in the previous step comes to the same mark.
- Unfold the paper and wrap around the tube again.
- Keeping the paper in place, mark the body tube at each of the creases in the paper and at the point where the paper overlaps itself.
- Extend the lines along the length of the tube using a door frame or piece of angled metal.
- Using double glue joints , assemble the 4 fins as shown in the Fin Diagram . Take note of the wood grain directions.
- Using double glue joints, attach the fins to the outside of the BT-60 as seen in the pictures. Make the bottom of the balsa section of the fins flush with the aft end of the body tube.
- Glue one launch lug in a corner where a fin meets the body tube and the other directly above it approximately 12.5" from the aft end of the rocket.
- Use your favorite method to attach the shock cord to the rocket.
- Paint the rocket as desired.
- Using a hobby knife cut a hole in the bottom of each of the plastic pumpkin candy cups to fit snuggly over the BT-60 tube. Make sure the hole is centered on the candy cup.
- Using a hobby knife, cut 2 notches (one top and one bottom) in line with each other on the back of each plastic pumpkin candy cup to allow for the launch rod to clear the cups when on the pad.
- Once the paint is dry, Attach the plastic pumpkin candy cups to the body tube using medium or thick viscosity CA glue. Make sure the notches line up the the launch lugs.
- Connect the other end of the shock cord to the nose cone.
- Connect the parachute to the nose cone or shock cord as desired.
Stability
The balance point on the Jack-o-Lance Beta is about 2/3 of the way up on the 4th pumpkin
(countin from the bottom) or approximately 10.25" up from the aft end of the body. This balance point was achieved
with no nose weight required and proves stable for both 18mm C motors and 24mm D motors. Flight
The initial flight of the Jack-o-Lance Beta was on an Estes C5-3 (using a spent 24mm motor case as a motor adapter). Boost was straight to about 200 ft. with ejection near apogee. Unfortunately, the parachute was packed too tightly into the body (which originally split in the middle) and the model free fell to earth. Only minor damage was sustained so the 'chute was re-packed with more baby powder and the Jack-o-Lance Beta was sent skyward again under C5-3 power. The 'chute was still to tight to fall out of the forward tube and this time one of the spruce fin tips broke and one fin came loose. The original design to separate in the middle of the body (between two of the pumpkins) was scrapped for a conventional nose cone blow (yea, I could have gone with a smaller parachute but I didn't want to). Again under C5-3 power, the Jack-o-Lance Beta took off this time to be returned safely home under it's large plastic 'chute.
Since then the Jack-o-Lance Beta has flown successfully on an Estes D12-5 to approximately 600 ft.
Copyright (c) 2000 Norman Dziedzic
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