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Project 2: Safe Bed #1


When a family has a young child, they will contain him in a crib when he sleeps so he cannot get out of his bed and play with things around the house, potentially hurting himself or breaking something. As he gets older and matures, his parents will move him out of his crib.
The issue is that parents of kids with mental disabilities may need something like a crib for longer. Since a 5 or 10 year old is larger, stronger, and craftier than a toddler and a conventional crib design will not do for him, a custom solution is needed.

The goal of this project is to design a safe bed for a young boy with autism. This design will prevent the boy from climbing and escaping the bed during the night, ultimately preventing him from injuring himself.

Team Members (From left to right): Graham Hicks, Austin Cox, David Bird, Caleb Ward, Almutaz Alnomi (superimposed)

Problem Statement

The safe bed project is carried out to prevent a child diagnosed with autism from escaping his bed at night and damaging or moving items around the house, potentially hurting himself in the process. The other functional role of the bed is to provide storage with drawers beneath it. The constraints of the project are almost nothing beyond that; we are very free to design the product as we see fit so long as it keeps the child from wandering the house by confining him to his bed. The bed should not be too tall and should take up the minimal amount of space necessary to accomplish its task.

Design Specifications

Since a twin size bed is desired by the family, we will construct it with dimensions of thirty-eight inches by seventy-five inches. We have placed a height limit of six feet for the bed from the bottom of the legs to the top of the frame to make it easier to move around and fit through doors. The bed will be designed to be simple, and any extra “aesthetic engineering” is not desired by the family. The color isn’t too important, but it was noted that their child liked the colors green and purple (The Hulk) and black and red (Spiderman).

Background Research

The background research for this project was fairly simple. Our team thought of different mechanisms that could be used in order to lock the doors of the safe bed from the outside so that the kid is not able to get out. We also researched previous safe bed designs and normal bed designs to understand the best possible solution for his needs.

Concept Design 1

This design concept features a rectangular frame with the front door sliding up so that it could lean against the top part of the bed. There will be notches along the four-by-four posts so that the door can easily slide up and down. There will also be pegs attached to the top of the bed so that the door has support to lean on the top frame without damaging any other parts of the bed. The bed also comes with a storage chest underneath that is mounted on casters and wheels.

Concept Design 2

The second design features a bed that contains padding along the lower portions of the bed frame. This concept also displays a latch mechanism so that the doors can only be opened from the outside. A plastic canopy covering the top of the bed is also drawn to prevent him from grabbing anything above him.

Concept Design 3

The final design concept displays a bed frame with vertical bars supporting the long sides of the bed and diagonally-crossed frames on the short sides of the bed. The top of the bed would be covered with a tunnel-like design that is supported with the bed legs and is connected with spaced bars instead of a solid canopy. There is also a latch mechanism at the end of the bed that can only be adjusted from the outside of the bed. This design is a combination of the first and second safe bed concepts.

Selected Concept Design

For this project, we decided to follow through with Concept Design One. There are several reasons that this design would be the best choice. The main reason is that his mother reviewed all three of these designs, and she preferred the bed to be constructed like our first conceptual drawing. It is also a good option because this design will take the least amount of time to build since there is no arc-shaped designs at the top of the bed. The bed will also be more easily transportable with this design. Because we are designing the bed to have detachable pieces, each square piece will be able to stack more easily into whatever vehicle is necessary.

Overview of Selected Design

Our final safe bed design needed to be further modified after speaking with the family about specifications. The bed will be constructed to be no more than about six feet tall. There will be about two feet from the ground to the top of the mattress. And about four feet of space will be left from the bottom of the mattress to the top frame of the bed. The mother also wanted a locking mechanism to be part of the storage space under the bed so that he will not be able to get inside and wanted the top of the bed to be constructed with cylindrical bars instead of having a flat piece of wood over the bed. She wanted her kid to have something to hang from.

Describe Design Details

To start, the bed is divided up into 8 individual pieces. These pieces are mainly locked together with screws but can be unscrewed and taken apart. It should be noted that the wheels and casters with the storage space are counted as one piece.

The pieces are as follows:

  • Front door with glued pegs (1)
  • Side covers glued to four-by-four posts (2)
  • Back cover (1)
  • Top frame with conduit bars attached (1)
  • Bottom bed frame (1)
  • Storage Chest with wheels (1)
  • Peg and lock (1)


The top cover consists of two 2×4 beams running the length of the frame and evenly spaced bars traversing the width of the frame that are placed into holes drilled into the two 2×4 beams. Holes are drilled down through the ends of the 2×4 beams so they can be attached to the side covers.

The side covers are designed similarly to the top cover, except that they are shorter than the top cover and oriented vertically, with holes drilled axially partway into the ends of the 2×4 beams so they can be screwed onto the 4×4 posts.

The front door is going to have a sliding mechanism with finishing wax so that the door can easily slide up and down the notches cut into the 4×4 posts. Similarly, the side pieces and back piece will be held into place with notches cut along the rest of the 4×4 posts.

There will be two half-inch plywood pieces that will hold the weight of the kid and the box spring bed. These will rest on the 2×4 pieces that will be designed to poke out from the inside section of the bed frames.

Since the front door slides up, the front 4×4 posts will be constructed to be a little bit taller than the back 2×4 posts. This is so the door has some clearance to turn on top of the bed without scraping any of the parts of the top frame of the bed. There will also be places inside the 4×4 posts for pegs that are attached along the edges of the door. This is so that the door can lock in place and provides a safer environment during operation.

Under the bed, there will be a storage chest that is roughly three quarters of an inch away from the bed itself. The storage chest will be mounted on wheels and casters. The front of the door will cover the storage chest under the bed so that, when the door itself is locked, the drawer will also be locked. This is so the family will only need one lock instead of two.

Engineering Analysis 1

A simulation was run in SOLIDWORKS on a beam with similar properties as the one likely to be used in construction.

  • Density: 0.0126 lb/in^3
  • Modulus of Elasticity: 1460 ksi
  • Flexural Yield Strength: 6 ksi

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Engineering Analysis 2

A simulation was run in SOLIDWORKS on a beam with similar properties as the one likely to be used in construction.

  • Density: 350 kg/m^3
  • Modulus of Elasticity: 10.1 GPa
  • Flexural Yield Strength: 41.4 MPa

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Engineering Analysis 3

A simulation was run in SOLIDWORKS on a beam with similar properties as the one likely to be used in construction. The current diamond-shape design of the sides of the bed would take extensive work to complete a SOLIDWORKS analysis on. So, this bar design was used as a substitute.

  • Density: 0.0126 lb/in^3
  • Modulus of Elasticity: 1460 ksi
  • Flexural Yield Strength: 6 ksi

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CAD Drawings

Bill of Materials

Document Fabrication Process

The bulk of the fabrication process included laser cutting the sides of the bed, cutting the channels and holes out of the four-by-four and two-by-four pieces, and painting. Other than this, small detail work was performed such as sanding sharp edges, chiseling the inside of the channels, cutting the big pieces of plywood, and screwing all the pieces of the bed together. Also, to make the bed more rigid, two angle brackets were placed at each corner of both the bottom and top frame of the bed.

Completed Design Photos


2022 Fall