The document describes a proposed design called DYNA-RACK for safely accessing items stored on high shelves without needing a ladder. It was created by team Cognoscere to address the common problem of storing items high up. Their solution involves a shelf with movable racks that can be lowered to the user's height using a steering wheel and pulley system. This prevents accidents from ladders. Design 2 was selected based on its ratings for ergonomics, aesthetics, cost, and other factors. It allows racks to be lowered and raised easily without electricity. A prototype was constructed and tested.

1. DYNA-RACK
Team name : Cognoscere
Problem sector : Housing
Subject : Design of safe shelf
Team Id Number : 573
Problem Statement
With the ever growing increase in the number of products available in the market, the need for storage
is always in the increase. Due to which, the things are put into the lofts and racks which are at a
greater height. In order to reach those things, we always search for a stool or ladder which is quite
risky. The user demographic is mainly homemakers, kids and senior citizens, who find it difficult in
using the stool or ladder. The probability of falling down is very high considering the difficulty in
using the stool or ladder. So there should be a way to overcome this common issue faced in every
house.
Solution
We have come up with an idea of designing a shelf with movable racks, which can be moved to
the user's level. This will help them in accessing their materials from their level of height. This will
prevent the possibility of accidents.
Design 1

2. Design 2 Design 3
Benchmark matrix (Ratings out of 5)
Design 1 Design 2 Design 3
Ergonomics 4 4 3
Aesthetics 2 4 3
Cost 5 4 3
User-friendliness 4 4 4
Portability 3 3 3
Maintenance &
serviceability
3 4 3
Lifecycle 4 3 2
Design complexity 5 4 2
Weight holding
capacity
4 4 3

3. Stability 1 4 3
Size 1 4 4
Total 36 42 33
Based on the results from benchmark matrix Design 2 is chosen for fabrication.
Here the racks at higher altitudes can be brought down to a comfortable height and put back to its
original position with ease. For this, we have designed a mechanism by which we can bring the top
racks down without using any electrical equipment. This mechanism involves the following
1. The rack to be drawn down is selected by means of a mechanical switching mechanism.
2. The rack is descended by sliding to the front and pulling it down to an optimal height, which
is user configurable.
3. The rack is accessed and then it is pulled up, ascending it back to its original position.
Construction
1. The pulling and sliding is done by a steering wheel attached to the metallic rope, driven by
the user.
2. The ropes run over several pulleys fixed at the top of each rack.
3. The racks are provided with wheels by which they slide over the track smoothly.
4. The racks are locked in their respective positions by using a locking mechanism.
5. The racks are inclined to an angle so that, out of gravity, it comes down when it is unlocked.
The speed of fall is slowed down by a damper connected to the steering wheel.
6. For the weight distribution of the falling rack, it is fixed to the rope by cradle mechanism.
7. Two ropes are used for each rack.
8. The tracks for the wheels are made by rubber sheet for firm grip and reliable movement of
racks.
9. The direction of movement of the racks depends on the direction of rotation of the steering
wheel.
10. The racks are provided with to protect the items from falling.
Working
At first, the rack to be moved down is selected using a slide switch. This switch unlocks the
particular rack as well as connects the steering wheel rope to the pair of ropes in the rack. Due to the
inclination, the rack slides and comes out of the shelf and down to the selected height. The height is
fixed by the user using a lock. The rope slides down along with the rack after which the things in the
rack are accessed by the user. Then when the steering wheel is rotated in counter clockwise direction,
the rope is pulled up and the rack slides up till it reaches its initial position. As soon as the rack
reaches its initial position, it gets locked.

4. Bill of materials
Materials Dimension(mm) Quantity Price(Rs)
Ply wood 1220x2440 2 1000
MS rod 1950x10 2 300
MS rod (hollow) 1200x10 2 300
pulleys 9 dia 18 200
wheels 20 dia 16 30
35 dia 8 10
15 dia 8 10
Nylon rope 1200, 6 dia 1 100
Nails 1.5 inch 140 20
Compression spring 30 x 3 x 100
Out x wire x length
4 50
Rotary Damper 10 dia, 30 rpm 1 1000
Total 3020

5. Proposed Design Exploded diagram
Final prototype (Front) (Backside)