UTRGV
/ COLLEGE
OF ENGINEERING AND COMPUTER SCIENCE / MECHANICAL
ENGINEERING DEPARTMENT
TEAM
6: Design of a Lifting Attachment for Riding Lawnmowers
|
SDI Students (L-R) |
·
Eurid Rodriguez ·
Carlos E Davila Hernandez ·
Luis D Rodriguez ·
Ruben Cardenas ·
Samantha Zuniga (not shown) |
|
Collaborators NVC Team 5 |
·
Andrea Perez ·
Josue Camacho ·
Sebastian Melendez ·
Jesy Martinez ·
Ramiro Cauntu ·
Karla Rubio |
|
Faculty Advisor(s) |
·
Dr. Rogelio Benitez |
|
Course Instructors |
·
Dr. Noe Vargas Hernandez ·
Mr. Greg Potter |
WHAT
IS THE PROBLEM WE ARE TRYING TO SOLVE?
WHY
IS THIS PROBLEM IMPORTANT?
CONCLUSION
LEARN
MORE ABOUT OUR DESIGN PROCESS
Welcome! We are team # 6 “The Raptors”, Eurid, Carlos, Luis,
Sam, and Ruben worked on this project during the Spring and Fall 2024 semesters
with faculty advisor Dr. Rogelio Benitez. Our project is a lifting attachment
for riding lawnmowers, aka The Yard Master Lawn Lift Pro kit. The hard-hitting
problems we tackled were that of introducing a robust and innovative product to
allow horizontal movement in low to medium work areas, allowing movement of
heavy material with minimal labor. We hope you enjoy this project as much as we
did.
Watch the Welcome Video!
The project
is aimed to solve the problems associated with common lifting and moving
machinery, like forklifts or pallet jacks, and to limit possible pains
associated with manual labor. These problems show up when the equipment or
vehicles are placed in a non-static environment where they simply are not
designed to function, and if they are they are designed for work in heavy duty working
areas they are not manurable and or cost effective. This creates a void where a
small-scale, light-duty device or vehicle designed to lift with minimal labor would
fit perfectly. We are simply trying to fill that void where manual labor falls
short and heavy machinery begins to play a role.
The classic
idea of a forklift is tied to industrial or large commercial settings where
large and heavy materials are moved constantly. Forklifts are [1] rarely seen
in any light duty or small-scale use; this is the area where our attachment
would work and stand out. The limitations mentioned are not related to the max
loads they can carry or their durability, their limitations are that of size,
cost, moveability, and genera access.
IMPORTANT TO KNOW
To [nv1] better grasp the ideas that would be
implemented in the design and to better understand fundamental topics related
to our product the following background research was conducted.
·
Forklift
safety regulations
·
Load
stability
·
Power
distribution
·
Lifting
mechanisms
·
Competitors
·
Injury
Statistics
Safety
regulations for Forklifts
Forklifts
are considered powered industrial vehicles and are commonly used for material
handling and lifting operations. Since the occupational safety and health
administration (OSHA) considers a forklift to be a powered industrial truck
(PIT), the operators of a forklift must follow the safety regulations placed by
OSHA.
Load
stability
Load
stability refers to the ability of a load to maintain its structural integrity
and balance during handling, transportation, and storage. Operating a forklift
does not only require you to understand the controls on how to operate it. It
also requires an understanding of load stability, which may help prevent future
accidents. There are several different factors that might come into play when
dealing with the stability of a load.
Lifting
mechanisms
Conventional
forklifts work with two types of lifting mechanisms. One of these is the
Hydraulic System, which uses cylinders, pistons and fluids to lift and lower
the loads placed on the forklift. The other mechanism is the Roller Chain
Pulley, which uses a pair of gears and a pulley system to lift loads. But
there are no limitations on the lifting mechanism, as a team explored other
types of mechanisms to understand the limitations, weaknesses and strengths for
a better understanding and a better and justified final choice.
Moveability
Moveability
refers to the forklift's ability to move throughout its environment which is
typically that of solid ground and level surfaces and only allowing for [4]
slight variation as to not throw off its center of gravity in turn unbalancing
the machine. This is crucial to the project and its safety for the user, if
this aspect were to not be taken into consideration, then the project would
simply be a nice piece of modern art.
Competitors
Competitors
for this product are also important to know and understand, below are the most
prominent products with their advantages and disadvantages. Considering that the
competition is vast and varied, generalized groups are listed.
·
Forklifts
·
Pallet
Jacks
·
Hand-Pulled
Dollies
·
Scissor
pallet lifters or Vertical Stackers
·
Lift
tables/ workshop lifters
·
Malual
labor
WHY IS THIS PROBLEM IMPORTANT?
Lifting mechanisms are essential tools
for improving efficiency and safety in various tasks. They reduce the risk of
injuries caused with labor-intensive lifting and make heavy workloads more
manageable with low manpower. Our project addresses these needs by providing a
lifting attachment specifically designed for riding lawn mowers—a solution that
currently does not exist in the market.
This project is important for several key reasons:
·
Efficiency: It allows users to save time and energy by integrating a lift
mechanism directly with a riding lawn mower, streamlining tasks that would
otherwise require additional equipment. It allows users to manage heavy loads
with speed and care that would not be seen if it had just been them.
·
Safety: By
reducing the need for manual lifting, the attachment minimizes the risk of
injury, making heavy lifting safer and more accessible for users of all skill
levels and situations.
·
Affordability: Unlike many existing lifting solutions, which are often out of reach
for the average consumer due to high costs, this attachment is designed to be
cost-effective, offering a budget-friendly alternative to expensive and large
machinery.
·
User-Friendly Design: The attachment features an intuitive design that is easy to install
and operate, ensuring accessibility for a wide range of users. And eliminating
the need for any specific training needed to operate other larger machines.
Our goal is to fill a gap in the market by delivering a product that is efficient, affordable, and safe. By focusing on these principles, we aim to create a practical solution that benefits homeowners, hobbyists, and professionals alike.
One of our proposed
solutions is rather straight forward, a combination of multiple designs from
various sources of pre-exiting mechanism and machinery. With Indepth knowledge and references covering our project, we
concluded that the attachment would be towed, similarly to a trailer, and lift
with scissor arms that powered by an actuator, with safety mechanism in the
form of sensors for the load and angle.
Once we
defined a clear solution idea (i.e. concept), we applied our engineering
knowledge to transform it into a real product. These were some of the important
design challenges and how we approached each one of them:
1.
Rigid attachment or trailer attachment
We needed to decide whether we wanted to
approach this project as a rigid attachment that is rigidly attached to the
frame of the lawn mower or approach it as a trailer attachment with a hitch. We
as a team decided that it was the best option to approach it as a trailer
attachment rather than a rigid attachment. This was mostly because of the rough
terrain that the lawn mower is usually operated on. We would have to consider
the impact factor that occurs on the bending and torsional forces, which will
depend on the terrain that the lawn mower is operating in. On the other hand,
the trailer attachment will only have forces acting on the hitch, which is the
only point of contact. Another reason why we chose the trailer attachment is
because the riding lawn mower will help act as counterweight when the lifting
mechanism has a load.
2.
Getting the correct measurements for the frame
of the platform
Since we decided to go with a scissor
lift, one of the main issues we ran into was getting the right measurements of
the frame for the platform. Getting the measurements wasn't really the issue,
but we also didn't want to end up with a huge trailer attachment. Our desired
height was 4ft, which meant that the scissor lift arms had to be over 4ft long.
This would require us to have a trailer that is longer than 4ft, for a riding
lawn mower that is only about 4ft long. We ended up approaching this issue by looking
at designs that included multiple sections of a scissor lift, rather than just
a single section.
3.
Getting the lifting
platform to touch the ground
In the first prototype we created, we
decided to add a set of wheels with an axle running across. The main issue we
ran into was that the platform was not able to touch the ground. Ideally, we
wanted it to be able to touch the ground so that the user doesn't have to pick
up from the ground (this is where most lifting injuries occur) to load it up on
the platform. If the platform is touching the ground, the user can easily slide
or roll the load onto the platform. Later the wheels were moved to be simply
under the frame without an axile. This meant that the platform can now easily touch the ground. This was accomplished by
the “bucket” design shown in the proposed solution section above.
4.
Choosing what lifting
mechanism to use
Our team was able to find many different
lifting mechanisms which included hydraulics, airbags, pulley system, rack
& pinion, etc. There were many things that had to be considered such as
load capacity, availability, accessibility, speed, precision and cost. After
evaluating these to ensure optimal performance, the team left two options open
which include a hydraulic lift or a pulley system. The hydraulic lift would be
ideal, but we are not sure we can afford it with the current budget that we
have. The pulley system gives us a cheap alternative. Close to when the team
was makeing final decision on the project an actuator
from the school became available and the team jumped at the idea of integrating
into our design. And, as you can see it was part of
our final design for this project.
5.
Material selection for
key parts
The team decided that this design would
be broken up into parts. Those parts or vital to the function of this project,
and they included the frame, the platform, and the scissor arms. Choosing the
right material and its dimensions is crucial to the durability, the robustness,
and the cost effectiveness of the project. This is why the decision the team
reached was that of using standard rectangular A500 steel for the frame and the
arms, and for the platform it was decided that the frame of the platform would
be make out of steel, but the platform would be plywood to keep the cost within
limits.
6.
Safety
Safety refers to the safety of the user
in this case. This was in the design from the beginning and was one of the
foremost ideas that was integral to the design. Even though the design of the
project has gone through many iterations the safety that it would provide was
the key to making this a viable product and did not go through many changes.
The safety comes from only allowing the project function within certain
thresholds, specifically focusing on the max load the platform and arms can
Hande and the tilt that the total machine can take. With a couple of sensors to
monitor these changes and control the actuator the machine becomes safe to
handle.
We found that physical prototyping was
very helpful to increase our understanding of the problem and the feasibility
of our solutions. Our first prototypes were simple but useful and we continued
evolving into more complex ones.
This was our
first prototype, it may be simple, but it helped us understand some major flaws
with our design. The main issue that was found was that this design didn't
allow the platform to touch the ground. This was a major issue since we wanted
to avoid the user having to lift anything up in order for
the lifting mechanism to be loaded. Most lifting injuries occur when the load
is being lifted from the ground, so this became a major issue that had to be
addressed. Another issue with this design was the swivel wheels. These wheels
would most likely not give the trailer enough traction to be riding offroad, so
we decided to look for alternatives.
This is our second prototype, which helped us understand that the scissor lift is not a viable option for us. This is because of the way the scissor lift works; it will not be possible for the platform to touch the ground. This was a key takeaway because we had to look for an alternative lifting mechanism.
This is our third prototype, it is still relatively simple, but it helped us understand that the placement of the support beams is crucial to this design. If the support beams are placed like shown above, the platform acts like a cantilever beam. It will be exposed to too many bending moments which will lead to it failing. This was a crucial finding because it allowed us to move the support beams more towards the middle, which would help relief those bending stresses that would occur.
This was our junkyard prototype, which helped us learn that the design with one screw jack wasn’t viable. Originally, we planned to have two screw jacks, one on each support beam. This idea was quickly eliminated due to our budget. If we went with two screw jacks, it would have taken a big portion on our budget, so we decided to try it with one to see if it would work. After creating the prototype, we quickly found out that this idea was not viable. This was due to the bending stresses that were placed on the screw. We noticed that having only one screw jack would put most of the weight on the screw, which is not ideal.
Besides prototyping the actual mechanism for lifting the load and keeping it stable, another section where prototyping took place was with the electronic system and its safety features. From simply having a display show the warring of tipping, or taking the values from the gyroscope and having them be readable this section was less of multiple different prototypes but rather taking our ideas and implementing them with what was already in place. The system ended up being rather simple, still in need of some optimization and workarounds but on its way to integrating with the mechanical aspects of the project.
Our lifting attachment for riding lawn mowers is
the product of multiple design, many tests, and iteration. This final product
combines functionality, durability, and user-friendly features, addressing the
needs of homeowners, landscapers, and professionals alike. While the core
design and functionality are complete, a few minor details are still being
refined to ensure the best user experience. Key features are present like the
robust frame, compact scissor mechanism, intuitive controls, safety functions, and
the attachment system.
Specifications:
·
Max load: 200 lb.
o
Safety factor of 3
·
Max lifting height: 36 in
·
Weight: to be determined
·
Power Requirements: 12V battery
·
Platform size: 4.5 ft x 3 ft
In Progress:
·
Final testing of mechanism
·
Integration of electronics system
·
Possible addition of coating to resist
corrosion
This project
has come to an end with this final prototype, there are still a few things to
finish for the final presentation but there are details. Some of the future
work that the product needs to be complete is:
·
The
wheel placement on the frame
·
Completion
of the platform
·
Installation
of the electronics system
o
Including
a power inverter for the actuator
·
Any
other detail for presentation
Besides this
the project could be taken further in several ways:
·
Making
the product smaller or bigger
·
Detaching
from the lawn mower and having it be its own machine
·
Wireless
control
IN CONCLUSION
For this project, our aim is to create a
product that is versatile, compact, robust, and, most importantly, makes life
easier for its users. We are confident in our ability to meet and exceed these
objectives. We remain committed to delivering an innovative solution that
addresses the needs of our target audience.
The team is currently in the final stages
of the project, this means that the project is about to be completed. This is
not the final product but the final prototype, this marks the end of our senior
design. This is a milestone and the culmination of our journey though many
months of hard work, testing different ideas, and refinement of those ideas. “There
is a thousand ways to skin a cat” this quote stuck with the team all throughout
this project, and in the time that we spent on this project it became very real
and important to the team. We believe that our solution is a balance of
versatility, robustness, affordability, and practicality and the team is
confident that the product achieves the goal we set out in the biggening.
We hope you have enjoyed reading about
our work and experience, we thank all of you for your time.
REFERENCES
1910.178 - powered industrial trucks. Occupational Safety and Health
Administration. (n.d.). https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.178
Home.
Arduino. (n.d.). https://www.arduino.cc/
We
went through a meticulous design process to arrive to the final solution. The
information on this page is a summary intended for the public. To learn about
the project details, contact Dr. Noe Vargas Hernandez at noe.vargas@utrgv.edu
The team
received help from various people, their help was critical to our success, we
would like to acknowledge the following for their advice, help, time,
and patience with Senior Design Team 6. Thank you all[nv2]
·
Dr.
Benitez
·
Dr.
Vargas
·
Mr.
Potter