Mechanical Feeding Device

List of group members:
Zachary Demko
George Gulas
Jonathan Bentley
Devin Johnson


We are designing a device to allow a young adult with limited mobility in his arms to have more independence.
The device will be a mechanical arm that will deliver various types of foods to his mouth via a push button activation.


We will be designing and manufacturing an automated feeding device to deliver various foods to the mouth.
Certain design specifications must be met in order to satisfy the recipient and his family. In order to set
these requirements we set up a meeting on September 13th with the young adult, his family, and his physical
therapist. Being able to meet with his therapist was very helpful because we were able to get a full sense of
his mobility. We discussed various options with everyone present and were able to get helpful feedback that
we will use in our design preparation. The therapist also mentioned a current prototype called the meal buddy.
Certain aspects of this prototype will be analyzed and dealt with accordingly.

Design Specifications

  • Mobility= 1 or more degrees of freedom
  • Push button activation
    • Button must be a maximum of 20" from subject's body.
  • Spoon must reach between 11" to 16" from table to mouth.
  • Must be durable to resist random impact.
  • Highly stable to resist tipping.
  • Semi-mobile in order to be transported.
  • Unit weight limit is approx. 10 lbs
  • Must be childproof (no sharp edges, or small parts that are easily swallowed)
  • Moderately slow set arm speed
  • Battery operated and/or 110v AC wall plug
  • The ability to scood various foods with various textures, densities, and viscosities.
  • Dishwasher safe utensils/ attachments.
  • Multiple attachments
  • Modified bowls
  • preset home and feeding positions

Design Concepts

Design Concept 1

This will be a pre-made 6 DOF mechanical Arm controlled by 6 servos that will be modified to scoop food from a bowl so a
child may eat from it.


  1. pre-fabricated
  2. easily modified
  3. power supply provided
  4. cheap
  5. light weight


  1. may require reinforcement
  2. complex with 6 DOF
  3. jerky motions
  4. possibility for need of more power
  5. programming changes

Design Concept 2

The design uses a simple screwing method to raise the spoon and screws outward with a separate screw system and has all systems completely covered.


  1. easy set up
  2. easily accessible parts
  3. no complex linkages


  1. bulky
  2. screw system may be tricky
  3. not easily carried around
  4. possible pinching wires in cylinder

Design Concept 3

The mechanism will use a simple linkage loop to reach out and scoop food using a cranking type linkage keeping purely planar motion.


  1. simple to make
  2. planar motion
  3. little to no programming
  4. reduced drippage


  1. potential for spills
  2. safety concerns
  3. stability

Concept Evaluation

Decisions Matrix

1 2 3
safety 3.5 4 3
durability 4 5 4
portability 4 3 4
stability 3 4 3
total 14.5 16 13

Scale:1-5 ; 1=Worst , 5=Best

From this matrix Design Number 2 is the best concept an will be what we will choose to use. Also, the screw design is best suited for the for us due to the simplicity of making the whole mechanism.

Design Overview

Give a brief description and schematics of the final design. Divide into as many subheadings as needed for organization.


Bill of Materials

Price Qty Total
Acme threaded rod $24.28 1 $24.28
HS-645 M6 Ultra torque $51.99 1 $51.99
HS-5055MG $32.99 1 $32.99
Acrylic Sheet $21.98 10 $121.98
RC Car Lithium Ion Battery $30 2 $60
Misc. Electronics $70 1 $70
Shipping $54.20
Total $415.44

Part Drawings

Assembly Instructions


Implemented Design


Summary and Conclusions