Car Modifications

Garrick Jennings
Marcos Moré
Zach Medina
Zach Henderson
Jared Hughes
Nicholas East



The client is 16yrs old and has Achondroplasia (dwarfism). He would like to learn and be able to drive, but his condition inhibits his ability to drive. The objective is to create a system to enable him to function properly in the car. This system must be removable so his family can drive the car as well.

Our system will consist of three main components:
Pedal extensions
Gear selector extension
Turn signal extension

Safety Regulations and Guidelines

Here is some in depth information regarding governmental regulation of car modications for handicapped drivers:

This link verifies that Tennessee has no regulations against spinning knobs on steering wheels.

Design Specifications

Our design must be easily removable as well as adhere to safety regulations and considerations. The product must be able to be adjusted and maintained by the client. The product must only extend the controls necessary to drive without inhibiting performance of the vehicle.

The design measurements include:
Brake Pedal -> 8" from foot to pedal; 7.5" to 10.5" giving 3" of foot throw; 3" to 5" (from firewall) giving 2" of pedal throw
Gas Pedal -> 10" from foot to pedal; 7.5" to 10.5" giving 3" of foot throw; 1" to 3.5" (from firewall) giving 2.5" of pedal throw
-There is a 4.5" and 10" vertical drop from the client's heel and toe, respectively, to the floor.
Gear Selector -> 9" from hand to gear selector, or 8" back and 6" up)
Turn Signal -> 4.5" Steering Wheel to turn signal clearance

Design Concepts

We are going to use cushions to properly position the client in the seat so he can look out of the car normally and see all the mirrors with an unobstructed view. The steering wheel extension will consist of 2-3 knobs mounted symmetrically on the steering wheel to give the client access to the wheel at the upper half of rotation. For the turn signal, we will bring the lever closer to the steering wheel using a paddle shifter design. The gas pedals will be mounted on a platform to raise the floorboard to where the client can rest his feet and operate the pedals normally. The platform will be secured to the floor using Velcro or some other means. The pedals will slide in a slotted track that allows forward and aft adjustment. There will be an adjustable link to "fine tune" the distance from the raised pedals to the car's pedals. A metal bracket and strap will secure the link to the car's pedals. The gear selector extension will be secured to the shifter using a metal bracket and strap. A "brake and caliper" design will be used to depress the button on the shifter.

Concept Evaluation

Consideration Design Concept 1 Design Concept 2 Design Concept 3
Cost 15% 2 3 5
Manufacturability 20% 4 3 5
Ease of use 25% 5 3 3
Safety 30% 3 4 4
Aesthetics 10% 4 4 5
Total Score 3.65 3.4 4.2
Design Choice Design Concept 3
Although the third design won the evaluation between the three concepts, we decided that there are aspects from each design that we liked. We believe we should create a combination of the designs that utilizes the best aspects of the three.

Design Overview



Describe the three types of analysis performed on the design. Use equations and schematics as needed.

Engineering analysis 1


Engineering analysis 2


Engineering analysis 3


Bill of Materials


Part Drawings

Assembly Instructions

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Implemented Design

Include pictures of the final product.

Summary and Conclusions