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Easy!!

October 24, 2018

http://bit.ly/EasyCars

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Overview

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  • EasyCarstm differ from FidgetCars primarily in the design of their wheel assemblies, which use 3D printed cylindrical bearing surfaces rather than spinner bearings.
  • Readily available components such as battery packs, motors and solar cells may be used to assemble a variety of car designs.
  • EasyCars facilitate learning about force, energy and motion enabling students to design, refine and optimize for both looks and performance.

Solar powered car uses a Pitsco motor and solar cell.

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EasyCar Designs

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1 and 2: Gravity Cars; 3: Bumper Car; 4: Sail Car; 5: Prop Powered Car;

6: Battery Powered Car; 7: Solar Powered Car

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On Your Mark ...

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Short sections of Raingo gutter (Slide 13) serve as ramps for down hill racing. Relative performance is determined by total distance traveled. Parameters include weight, wheel size, and car dimensions.

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Self Powered EasyCars

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Sail Car

Gravity Cars

Bumper Car

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Motor Driven EasyCars

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Battery Pack

Battery Pack

Pulley Driven

Propeller Driven

Wheel with integated pulley

Propeller designed in Tinkercad

Car Base: car_base.stl

Wheel1 (1X): wheel1_218.stl

Wheel1 (1X): wheel1_pulley_218.stl

Wheel2 (2X): wheel2_218.stl

O-Ring: #218 1 ½” x 1 ¼”

Car Base: car_base.stl

Wheel1 (2X): wheel1_218.stl

Wheel2 (2X): wheel2_218.stl

O-Ring: #218 1 ½” x 1 ¼”

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Solar Powered EasyCar

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Pitsco Solar

Panel

Car Base: car_base.stl

Wheel1 (1X): wheel1_218.stl

Wheel1 - pulley (1X): wheel1_pulley_218.stl

Wheel2 (2X): wheel2_218.stl

O-Ring: #218 1 ½” x 1 ¼”

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Sail Car

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Use low quality print setting; 10% infill for body and sails and 100% infill for wheels; assemble wheels as described on slide 17.

Length = 134 mm

Width = 45 mm

Height = 20 mm

Wheel Diameter = 41 mm

Sail Car: sail_car.stl

Wheel1 (2X): wheel1_222.stl

Wheel2 (2X): wheel2_222.stl

Sails: sails.stl

O-Ring: #222 1¾” x 1½”

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Bumper Car

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Bumper Car: bumper_car.stl

Wheel1 (2X): wheel1_218.stl

Wheel2 (2X): wheel2_218.stl

Spring: bumper_car_spring.stl

O-Ring: #218 1 ½” x 1 ¼”

Orient with upper surface of car on print bed; use low quality print setting; 10% infill for body and 100% infill for wheels; assemble wheels as shown in slide 17.

Length = 134 mm

Width = 45 mm

Height = 15 mm

Wheel Diameter = 34 mm

The Bumper Car is equipped front and back with flat springs which absorb and exchange energy in keeping with the laws of conservation of energy and momentum.

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VW with Bumpers

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VW with Bumpers: vw_bumpers.stl

Wheel 1 (2X): wheel1_210.stl

Wheel 2 (2X): wheel2_210.stl

O-ring: #210 1” x ¾”

Orient with side of car on print bed; use low quality print setting with no supports; 10% infill for body and 100% infill for wheels; assemble wheels as described on slide 17.

Length = 97 mm

Width = 25 mm

Height = 55 mm

Wheel Diameter = 23 mm

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Minis

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Bumper Car Mini: mini_bumper.stl

Sail Car Mini: mini_sail.stl

Flatbed Mini: mini_flatbed.stl

Spring: mini_spring.stl

Wheel1 (2X): wheel1_210.stl

Wheel2 (2X): wheel2_210.stl

O-Ring: #210 1” x 3/4”

Orient with upper surface of car on print bed; use low quality print setting; 10% infill for body and 100% infill for wheels; assemble wheels as shown in slide 17.

Minis are small and fast printing yet structurally sound versions of the larger cars described in previous slides. They are ideal for introducing younger students to informal science based inquiry.

Length = 80-110 mm

Width = 25 mm

Height = 13 mm

Wheel Diameter = 23 mm

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More Printables

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Parts

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Rain Gutter Ramp

Raingo 4-1/4 in. H x 5 in. W x 10 ft. L Vinyl C Gutter. ACE Hardware and Aubuchon Hardware: $7.99

0.45V, 400 mA: $4.35 each

2V, 200 mA: $6.45 each

$1.95 each

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O-Rings

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1/2" ID, 3/4" OD, 1/8" Width

Fits 16 mm diameter wheel

Package of 500 @ $15.14:

#206

#210

#214

1-1/4" ID, 1-1/2" OD, 1/8" Width

Fits 34 mm diameter wheel

Package of 100 @ $11.86:

#218

3/4" ID, 1" OD, 1/8" Width

Fits 23 mm diameter wheel

Package of 100 @ $9.74:

1-1/2" ID, 1-3/4" OD, 1/8" Width

Fits 41 mm diameter wheel

Package of 100 @ $12.97:

#222

1" ID, 1-1/4" OD, 1/8" Width

Fits 27 mm diameter wheel

Package of 100 @ $11.05:

1-3/4" ID, 2" OD, 1/8" Width

Fits 56 mm diameter wheel

Package of 100 @ $15.63:

#226

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Create Wheel Assemblies

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OD = 14.0 mm

ID = 10.0 mm

The same axle cylinder design is used for all car sizes, only the length changes depending on the width of the car. Body holes such as those in the VW are 10.0 mm in diameter.

Axle Cylinder: axle_cylinder.stl

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Assemble Wheels

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  • Install O-rings on all four wheels
  • Insert long shaft of Wheel 1 into axle housing
  • Insert short shaft of Wheel 2 into long shaft of Wheel 1
  • Press firmly until fully seated

Wheel 1

L= 40, 50, 60 and 70*

Wheel 2

Completed Wheel Assembly

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Determine O-ring Size

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This handy O-ring gauge accommodates o-rings with outside diameters ranging between ¾” and 2 ¼”.

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Create a Rain Gutter Track

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Raingo plastic rain gutter can be cut into two 5 ft. sections or four 2.5 ft sections for table top explorations of energy and motion concepts. The connectors facilitate joining multiple track sections.

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Use Fidget Car O-Rings

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Many Fidget Car designs used the #214 O-ring (1" ID, 1-1/4" OD, 1/8" Width).

EasyCars can accommodate the same O-rings in conjunction with the following wheel designs as long as the body width is 45 mm:

Wheel 1 (2X): wheel1_214.stl

Wheel 2 (2X): wheel2_214.stl

STL

STL

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For additional information about designing and printing EasyCars, please contact

David S. Perloff, Ph.D.

daveperloff@gmail.com

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