Deliverables

1. ENGR 101: Design Brief I
Section 64, Group 10
Group members
Patrick Devaney, pwd34@drexel.edu
Donovan Barry, dfb46@drexel.edu
Pedram Keyvani, pk524@drexel.edu
Abstract
This design brief contains information for the first simple
machine of a two-dimensional Rube Goldberg machine. After
rough sketches and precise calculations, the device was built and
functions properly.
Introduction
An inclined plane is to be used as the first simple machine in the first of six “events” in our two-
dimensional Rube Goldberg machine. This design brief will analyze inclined planes and describe how
they work and why they are important.
Theory
An inclined plane consists of an object, and a flat surface that is resting on an angle, or a tilt, shown in
figure 1. In an inclined plane, work is done over a longer distance and with less force. In our design, we
are dropping a ball down an inclined plane and getting less force that we would if it went straight into free
fall. A free body diagram depicting this is shown in figure 2. The rate at which an object falls down a
tilted surface is determined by the angle of inclination and is shown in equation 1. This system can be
evaluated theoretically by performing a force balance using the free-body diagram shown in Figure 2. To
perform this analysis, certain assumptions must be made about the pulley system, and the assumptions are
as follows: The mechanical advantage is equal to the length of the incline divided by the height.
The total force exerted on the object is found using the following equation:
F= mg cosθ-Ff
Equation 1
Where F is the net force exerted, m is the mass of the object, g is the acceleration due to gravity, and θ is
the angle of inclination and Ff is the force of friction.

2. Experimental
The main track of the inclined plane was fashioned from two red K’nex rods connected linearly by two
yellow connector pieces at the bottom of the ramp. The yellow pieces are combined by a yellow rod. At
the top of the ramp the two main red rods were conjoined by a V shaped apparatus constructed with three
gray connector pieces at each end point bound with short white rods. An elastic band were fashioned to
the rods going through the back of the pegboard to hold the inclined plane in place.
Table 1: Materials list.
Quantity Description
2 K’nex red rod (K’nex part #509532)
2 K’nex white rod (K’nex part #90951)
2 K’nex standard yellow connector (K’nex part #90906)
2 K’nex standard light gray connector (K’nex part #90903)
1 K’nex standard yellow rod (K’nex part #90953)
1 Rubber Band
1 Golf Ball (45.9 g)
Results
Releasing the ball from the top of the ramp will allow the ball to travel down the inclined plane. The
resulting net energy of kinetic and potential combined will transfer to the next event. Energy lost will be
accounted for my heat and sound created by friction from both sides of the ramp and a bump caused by
the connectors at the end of the ramp.
Figure 1: inclined plane Free-body diagrams: force balancing
Figure 1 Figure 2

3. Discussion
The initial design of the ramp failed to support the weight of the golf ball and allowed the ball to fall
sideways off the ramp. This problem was solved by adding the V shaped apparatus at the top of the ramp
to add support area. The mechanical advantage of the inclined plane is three. Mechanical advantage of a
inclined plane is length divided by height (6/2 is 3)

4. ENGR 101: Design Brief III
Section 67, Group 10
Group members
Patrick Devaney, pwd34@drexel.edu
Donovan Barry, dfb46@drexel.edu
Pedram Keyvani, pk526@drexel.edu
Abstract
This design brief contains information for the fourth simple machine and the design for the
alternative event sketch of a two-dimensional Rube Goldberg machine. After rough sketches and
precise calculations, the entire device was built and functions properly.
Introduction
Two gears are to be used as the fourth simple machine, and a potato is to be used as the alternate
energy source in a two-dimensional Rube Goldberg machine. This design brief will analyze both
the gears and describe how they work together for this machine. In addition the potato will be
analyzed I this brief to show how it can be used to provide small amounts of electricity.
Theory
A wheel and axel works by rotating together. They each make one revolution at the same time,
but the linear speed of the wheel is greater than the speed of the axel, much like the wheels on a
car. Similar to the lever, the further away from the point of rotation, the easier it is to rotate the
object (i.e. why a key has a large head for your hand to twist it; the same concept applies with
doorknobs). A gear (Figure 1) is a simple machine that transfer force from one even to another
with a relatively low force traveling a greater distance. Gears can increase the speed of a process
at the cost of force if the first gear is smaller than the second gear (assuming only two gears like
our design) or increase force at the cost of speed (if the first gear is larger than the second gear)
gears also change direction in pairs.
The alternate event is a digital clock powered by a potato. This unconventional power source is
made possible by the process of converting chemical energy to electrical energy. The lever that
falls onto the potato chunks has copper and zinc barbs attached to it. Within the potato chunks
the copper and zinc ions are transferred through the potato into the metal barbs and then through
the wiring to the clock. The potato itself acts as a battery. The bigger the potato, the longer the
clock will stay on. Once all of the ions inside the potato are used up, the clock turns off. Also, the
potatoes are not safe to eat after they have been used. The reaction that takes place during this
process alters the composition of the potato.

5. Experimental
The gears are simple pre-made K’nex pieces pined to the peg board. The gears are clipped on
either side in a way that they are both stable and free to move. The gear spins after it is hit by the
lever. We designed an arm and attached it to the second gear. Table 1 lists all the materials used
in this section. When the gears turn, the arm wil then knock over a set of dominos. The force
from the initial hit is transferred through both gears and into the dominos. The potato clock
consists of two metal stakes attached to a lever arm, which will pierce two lumps of potato
connected to a clock. Table 2 lists all of the materials used in the potato clock.
r1
r
r
Figure 1: Gears
Figure 2: Potato Clock 12:00
Potato
Zinc
Stake
Copper
Stake Digital
Clock

6. Table 1:
Quantity Description
2 2.4” K’nex red rod (K’nex part #509532)
2 K’nex standard tan clip connector (K’nex part #90900)
2 K’nex white rod (K’nex part #90951)
2 K’nex standard yellow connector (K’nex part #90906)
2 K’nex standard light gray connector (K’nex part #90903)
4 K’nex standard orange clips
1 K’nex standard large yellow gear
1 1” K’nex standard yellow gear
Table 2:
Quantity Description
2 Cooked Lump of Potato
2 Copper Stake
2 Zinc Stake
1 Clock
1 Wood lever arm
Results
At first, we figured that turning the smallest gear would be the best design for our machine. After
experiments and research we found out that we were very wrong. It is much easier to turn a
larger gear. Since the larger gear is twice as large as the smaller gear, the smaller gear will turn
twice as much as the larger gear. If the large gear turns 45 degrees, than the small gear will turn
90 degrees. The hardest part of this section was getting the gears to turn efficiently. First, we
experimented with different designs of levers to create the best arm for the maximum contact.
Our best design was a lever with 2 cm on one side of the fulcrum, and 10 cm on the other side of
the fulcrum. This gives us a sturdy final product with a mechanical advantage of 5. We were able
to do this with minimal calculations. The sources of error for the gears include human error for
all measurements, the friction between the gears and the axis, the friction between the gear arm
and the lever arm. For the potato clock, we decided that a cooked potato will be much easier to
pierce than a raw potato. We experimented with both potatoes, and found that each potato
provided enough electricity.
Discussion
Overall, both the gears and the potato clock in our Rube Goldberg Machine operated as expected
after much trial and error. Our calculations for each machine matched the results within reason.
The gear is the fourth and final machine to be used in the Rube Goldberg Machine. The
mechanical advantage of the large gear is 16 because the radius of the gear is 2 inches, and the
radius of the axis is 1/8 of an inch. The mechanical advantage of the second gear is 8 because the
radius of the gear is 1 inch and the radius of the axis is 1/8 of an inch. The potato clock is our
alternate source of energy. Through electrochemistry, the potato produces enough energy to
power a clock.

7. Robotics Module: Design Proposal
ENGR 102 – Winter 2015 – 2016
Engineering Design Lab II
Lab Section: 070 Date Submitted: February 04, 2016
Group
Number:
1
Section
Instructor:
Professor Caroline
Schaur
Section Fellows: Bita Alizadehtazi
Group
Members:
Derek Campbell Aaron Bennett
Pedram Keyvani

8. ENGR 102, Winter 2015 - 2016 Section 070, Group 1
Page 1
Design Constraints
When having to program the robot to be able to complete tasks, such as, scanning the
area for specific canisters, and then transport them to a specified location, there are many factors
involved. The ones, which gave us the most trouble were: only being able to use four sensors
where if we could use five would be ideal, placement of the sensors in relation to the gripper.
When trying to decide which sensors to use we settled on the color, ultrasonic, light and touch
sensors. As for the placement of the sensors, we knew that the ultrasonic and the color sensors
had to be in the front, because of the design of our gripper, so the design of our gripper was
shaped so that if the robot rolls up to a canister it scan to see if it’s the canister we intend to
move.
Design Proposal
Mechanical Design:
Robot Construction:
This NXT robot has to be a particular design due to the shape of the computer. The simplest
set up of the NXT robot is by having a strong base, with a maximum of two big wheels and a
smaller one that will allow the robot to turn better, this is shown in Figure 3. The intended
“head” of the robot is what we used as our base, because it is visibly sturdier than any
combination of k’nex pieces we were given. In the front of the robot, there are grippers as you
can also see in Figure 1 and 2, as well as the placement of the color and ultrasonic sensors.
The Gripper Design:
The gripper design is what makes each robot have its own identity. First, it was placed in
the front of our robot, as shown in the figures above. For our robot to have the highest efficiency
Figure 1: Front View Figure 3: Side ViewFigure 2: Top View

9. ENGR 102, Winter 2015 - 2016 Section 070, Group 1
Page 2
in order to move the waste from its initial location to where it needs to go, it makes the most
sense to put the gripper in the front. The design of the gripper supports the ability of being able
to move each item up during the competition. On each side of the gripper, there are three
separate L shaped k’nex pieces. The L shape k’nex pieces, which are being used as claws are
placed on top of one another. We doubled up on the k’nex pieces on each side of the gripper to
allow the robot to move the items a lot easier. Also, as shown in the three figures above, we
placed both the color and ultrasonic sensors in the ideal positions; that being said, the sides of the
gripper are positioned in forward/bent facing manner, This reduces the chances of any possible
interference with either sensor. We also have designed to have two arms, one up and one down
(parallel to each other), as can be seen in figure 1, on each sides for added stability. Lastly, our
gripper has is centered around a simple gear design, in which one arm/gear is connected to the
motor and the other ones will rotate as the one connected to the motor rotates.
The Motors:
The two motors that will be powering the rotation of the wheels will be placed on the
bottom half of the robot, which is shown in both figures two and three. The third motor we used
is for the gripper, so that when once the sensor pick up an object it will then tell the motor to turn
so that the gears turn to open up the gripper and late tighten them back.
The Sensors:
For this NXT robot, the ultrasonic, light and color sensors will be used. The color and
ultrasonic sensor will be placed on the sides of each arm of the grippers facing forward so that
they are able to pick up objects. The light sensor will be placed on top the robot, centered
towards the middle. The sensor will be at the highest peak of the robot. It’s best that the color
and the ultrasonic sensor not be too high or too low, if so it will pick up a bad signal and not be
able to read it properly.
Algorithm Design:
The robot will start by scanning the area for an object with the ultrasonic sensor. After an
object it sensed it will begin to turn an object is found, it will scan object for its width then
proceed to then rotate the wheels to go around it, unless it is a wall then it will simply turn
around. And depending on if the width matches that of what would be a canister, then it will
open the gripper, move forward and then close the gripper and then find the light and move
towards it so that it will then take canister there. Once within a certain distance, it will reach the
area to leave the canister. If the canister isn’t magnetic, the robot will find the light user the light
sensor, move forward to the light, and use the color sensor to determine when it is in the trash
drop off zone. After this the robot will search for another canister. If canister is magnetic, the
robot will move it to the area where the trash is supposed to go.

10. ENGR 102, Winter 2015 - 2016 Section 070, Group 1
Page 3
Figure 4: Flowchart of Algorithm