This little "pocket size" car will not win any distance or speed records, but it's quite durable, and it runs in two modes; "power" and "coast". Power mode is when the car is unwinding the rubber band from the axle. When the rubber band is completely unwound, it disconnects from the axle allowing the car to enter coast mode for additional distance.
The symmetrical design of the car requires eight 3D printed parts (two chassis sides, two axles, and four wheels) yet only three unique parts (chassis, axle and wheel), with all parts small enough to fit on most if not all 3D printers.
Design using Autodesk Inventor, sliced using Cura, and printed in PLA on an Ender-3 3D Printer.
Procedures
STEP 1: Prepare Parts
Part: Axle_Initials
New PART file
Start 2D Sketch
CREATE a RECTANGLE two point center
DIMENSION (.230 x .237)
CREATE a CIRCLE that shares the center of the rectangle.
DIMENSION Circle ( Diameter .330)
TRIM top and Bottom of Circle
DELETE The left and right line of the square.
FINISH SKETCH
EXTRUDE (2.184)
START 2D SKETCH on Top of the object
CREATE Sketch by using either LINE, RECTANGLE, TRIM, HORIZONTAL, VERTICAL.
DIMENSION using the measurements on the right.
FINISH SKETCH
EXTRUDE (.314)
FINISHED AXLE
PART: Wheel_Initials
New PART file
Start 2D Sketch
CREATE a RECTANGLE
DIMENSION (.327 x .590)
CREATE a small RECTANGLE at the bottom right or the larger Rectangle.
DIMENSION (.055 x .235)
CREATE CIRCLE
DIMENSION (Diameter .140)
DIMENSION center the circle in the middle of the top line ( .164)
MODIFY TRIM top of the circle and the line through the circle.
FINISH SKETCH
3D MODEL
CREATE REVOLVE
Select the large and small rectangle PROFILE.
AXIS select bottom line (turns red)
EXTENTS Full
Press OK
START A 2D SKETCH on Right Side
CREATE a RECTANGLE two point circle in the center of the wheel.
DIMENSION rectangle (.248 x .243)
CREATE a CIRCLE in the center of the wheel
DIMENSION circle (Diameter .347)
MODIFY TRIM top of circle.
Delete the left and the right line of the rectangle.