Creative Inventions and Robotics

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Laboratory
Soap Box Racer
Creative Inventions and Robotics www.build-it-your
self.com
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Soap Box Racer

• This project requires close supervision.
• Anyone who does not follow the tool rules gets
  immediately benched.
• Soap Box Racers may not be run anywhere near cars.

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Soap Box Racer
The Problem Dirty gas guzzlers are fouling up
our air. The Mission Your mission is to build
a clear air mobile.
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Soap Box Racer
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Soap Box Racer
Soap Box Racers may not be run anywhere near
cars. Our goal is to replace these ugly, gas
guzzlers with more intelligent machines. Which
car would you want to drive?
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Soap Box Racer
Tool Rules
1 Dont cut your finger off. 2 Hold work
firmly. 3 Wear goggles. 4 Think what happens if
you slip. 5 Clean up. 6 I Cant is forbidden..
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Soap Box Racer
How to ensure your saw cuts are straight.

1. Mark straight, perpendicular lines using a
   T-square.
2. Position yourself so you can move your saw easily
   and with leverage.
3. Hold your work firmly with a clamp, or your foot
   or with the help of a teammate.
4. Make smooth saw strokes. Let the saw do the work.

All the materials you will need are listed at the
end of these slides.
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Soap Box Racer
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Start by mounting wheels on the rear and front
axles. It is recommended that if you are going
to motorize your racer, you use 10 wheels or
larger with ball bearings. This will give you
the best power to drive heavier loads. Saw 1 x
3.5 pine boards for the rear and front wheel
supports. Read the scale on the drawing to
figure out how long these boards should be.
Front axle
Rear axle
Use big rear wheels if you want to motorize your
racer.
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Soap Box Racer
Measure and mark locations for drilling carefully
as shown. If your measurements are not accurate,
your wheels will be crooked and you will run like
a turtle!
Drill 4 holes as shown here in the ends of the
2.5 front axle board and the 1.5 rear axle
board.
5/16 drill bit
2
Scrap wood to protect from drilling into the
table
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1
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Soap Box Racer
2 long x 1 wide U bolts
5x ½ lag bolt
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Soap Box Racer
Alternative Wheel Mounting Ideas
If you cant find the proper U bolts, you can use
4 metal straps and screw them to the axles.
Or you can use ½ copper pipe fasteners. To hold
the lag bolt securely, use a plastic tube that
just fits around the lag bolt.
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Soap Box Racer
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Connect the rear and front axle boards to the
main chassis beam. The front axle will rotate
around a 2.5x½ lag bolt that goes through the
front axle and main chassis beam. The rear axle
will be be screwed to the main chassis beam so it
cannot rotate. Cut a 1 x 3.5 pine board for
the main chassis beam. Use the scale drawing to
figure out how long this board should be.
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Soap Box Racer
Measure the exact center of the 2.5 x 3.5 front
axle board.
½ drill bit
Scrap wood to protect from drilling into the
table
2.5x3.5 front wheel assembly
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Soap Box Racer
Drill a ½ hole in one end of the 3 main chassis
beam that connects the front and rear axles.
½ drill bit
Scrap wood to protect from drilling into the
table
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Soap Box Racer
2.5x ½ lag bolt
3x3.5 main chassis beam
Drill ½ holes
2.5x3.5 front wheel assembly
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Soap Box Racer
1/8 drill bit
Scrap wood to protect from drilling into the
table
3x3.5 main chassis beam
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Soap Box Racer
1.25 sheet rock screw
1.5x3.5 rear wheel assembly
3x3.5 main chassis beam
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Soap Box Racer
If any sheet rock screws poke through the wood,
immediately put hot glue or duct tape over the
screw tips to protect against nasty cuts!!!
Do not ignore this important step. Always check
for protruding screw tips. They are among the
most dangerous parts of this project.
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Soap Box Racer
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Build the seat back base.
Cut 3.5 x 18 3.5 x 10 1.5 x 10 Drill 1/8
holes.
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Soap Box Racer
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Build the steering support.
Cut 3 pieces 3.5 x 10 1 pieces 1.5 x
10 Drill 1/8 holes.
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Soap Box Racer
Make the steering wheel.
Cut and bend coat hanger wire in a circle.
WEAR GOGGLES!
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1.5
3/4 dowel
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Wrap foam rubber or pipe insulation around the
wire and wrap with duct or electricians tape.
Drill a 5/16 hole big enough to thread 1/4
nylon rope.
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All other holes should 1/8
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Soap Box Racer
Make the steering wheel.
Screw a 3/4 U clamp around the 1 steering
shaft. Wrap the shaft with foam rubber to keep
the shaft from turning.
Turn the steering assembly around and insert a
lock screw to keep the shaft from turning.
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Soap Box Racer
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Screw 3/4 U clamps to the steering support. Put
a ¾ washer on the steering shaft and insert the
steering wheel shaft into the U clamps.
Add a ¾ washer on the end of the steering wheel
shaft and insert screws to keep the washers in
place.
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Soap Box Racer
Thread ¼ nylon rope through the big hole in the
steering shaft. Wrap one end of the rope
around the steering shaft 5 times in one
direction. Do the same with the other end.
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Soap Box Racer
You must cross the rope ends to make the wheel
axle follow the steering wheel properly. Thread
the rope through screw eyes on the main chassis
beam.
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Soap Box Racer
You can buy curtain cleats at a hardware store
for 2 each. Or you can insert screws at an
angle as shown below to simulate a cleat. The
cleats must be exactly 10 from the center bolt.
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Soap Box Racer
Use a sailors cleat hitch knot to secure the
rope ends .
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Soap Box Racer
Add a foot rest and a dash board. You can mount
a break pedal on the foot rest.
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Connect the 3.5 x 10 break pedal to the foot
rest with a strap hinge. Insert 2 screws. Add
rubber bands as shown to keep the pedal off the
ground until it is pressed to stop the racer.
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Soap Box Racer
Now you have a good basic structure on which to
add extra features and decorations.
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Soap Box Racer
You must look cool
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Soap Box Racer
You must look cool

• Add a page in your PowerPoint Lab book that
  advertises the features on your racer. Google
  how the big boys advertise their cars and see if
  you can outdo them.
• Make a hood ornament that moves when you pull a
  string.
• Build a comfortable seat from your Moms softest
  pillows.
• Make flags.
• Make clever license plates and bumper stickers.
• Decorate a dash board.
• Add flames coming from the back.
• Add sponsor decals.
• Add a cup holder, horn, bell, radio, head lamps
  and rear view mirrors.
• Youll need to collect a big box of premium
  quality junk.

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Soap Box Racer
You must be fast

1. Make sure your wheels spin freely and are well
   aligned.
2. Look for ball bearing wheels.
3. Reduce weight for downhill drag racing.
4. Tighten your steering rope for slalom racing.
5. Add weight to increase momentum for distance
   racing.

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Soap Box Racer
Awards

1. Best teamwork
2. Best craftsmanship
3. Best engineering
4. Best looking
5. Fastest downhill drag racer
6. Most accurate slalom racer
7. Longest runner
8. Best breaks

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Soap Box Racer
What you should learn

• 3 Laws of the Lab
• Problem and mission
• Extreme building
• Presenting your ideas
• 5 Tool rules
• Cutting straight
• Problem solving tricks
• Premium Quality Junk
• horn, mirror, radio, lights, license plate, hub
  caps, front hood logo.

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Soap Box Racer
If you think you are a hot shot automotive
engineer, you can try motorizing your
jalopy. You should look for wheels that are at
least 10 radius and that have ball
bearings. If you are a big palooka, you may need
two 19V electric drills to pull a heavy load!
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Soap Box Racer
Connect the electric drill to the support board
with plastic ties. Drill holes in the support
board for the plastic ties. Connect the support
board to the frame with a hinge.
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Soap Box Racer
After you connect the motor support board and
foot pedal to the frame with hinges, then tie a
rope from the support board to the foot pedal.
You will need to attach a spring to the support
board so the motor is normally not touching the
wheel.
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Soap Box Racer
Tools, supplies and approximate prices on the
following pages are from Home Depot. If you
are clever, resourceful and recycle minded, you
may be able to reduce the cost of your racer by
more than half.
Half Price ???

• A few ideas
• Look for wheels on an old baby carriage.
• Use a hand drill and screw driver instead of an
  electric drill.
• Share tools with your buddies and neighbors.
• Look for recycled wood.
• Use your parents broom stick instead of a ¾
  4-foot dowel.
• Figure out a way to use wood instead of U bolts
  to secure the wheel lag bolts.

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Soap Box Racer
Tools from Home Depot
Prices may change.
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Soap Box Racer
Supplies from Home Depot
Prices may change.
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Soap Box Racer
Supplies for Motorized Racer from Home Depot Same
as for non-motorized except add purple rows
Prices may change. Contact Build-It-Yourself
for plans to motorize your racer.
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