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Additionally, this machine can be used for peewee football players to practice ... In order to establish the features the football launcher should include, ...
Typology: Schemes and Mind Maps
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A Baccalaureate thesis submitted to the School of Dynamic Systems College of Engineering and Applied Science University of Cincinnati
in partial fulfillment of the requirements for the degree of
Bachelor of Science
in Mechanical Engineering Technology
by
Cory King
May 2015
Thesis Advisor: Muthar Al-Ubaidi, Ph.D.
I would like to thank my advisor, Professor Muthar Al-Ubaidi, for providing me with the insight and guidance needed to complete this project successfully. I would also like to thank my friends who let me bounce ideas off of them and my family who helped me with the fabrication.
Parents with injuries or handicaps often find it difficult to throw a football with their children. It would be beneficial to these people to have a machine that can throw a football for them (there are no such products available in today’s market). This would allow a person to spend quality time with their children while also getting their children active. Currently the only similar products available are made for high school and professional athletes. The machine shown in Figure 1 below is an example of a professional football throwing machine.
Figure 1 – Football Throwing Machine
In order to establish the features the football launcher should include, multiple interviews were conducted. Full interview notes can be found in Appendix A.
Interview with potential customer: John King 2373 Halfhill Rd. Bethel, OH 45106 9/9/14 He has back and shoulder injuries that prevent throwing a football. He has three children. He likes the idea of a machine that can throw a football for him and make playing with his kids easier. His biggest concerns were the cost and ease of use of this machine. Important customer features to include: stability/anchoring, easy loading of the ball, proper power – adjustable to be appropriate for different ages of children, easy to maintain, either light weight or on wheels for easy mobility.
Interview with potential customer: Jeff Saylor 10934 Liming Van Thompson Rd Hamersville, OH 45130 9/11/14 He is older with young grandchildren and has difficulty
throwing a football. He would like the machine to be able to shoot a ball 15-20 feet with a consistent path of travel. Important customer features to include: consistency of ball path and distance, machine does not rock when in use, easy to load, easy to move.
The JUGS Football Machine™ throws perfect passes, punts and kickoffs to any precise spot on your field. Your players can practice catching perfect spirals or end-over-end "kicks" at any speed or distance you choose from 5 yards to 80 yards. This product is very expensive for home use, has too much power for use with young children, is very heavy, and retails for $2,500 USD.
Figure 2 – JUGS Football Machine
The Snap Attack football machine is designed by football coaches, the NEW Snap Attack football training machine is a snap, pass and kick machine that will maximize your time on the most difficult to practice phases of the game. This product is extremely expensive, overly complex for the intended application, is only reliable if the ball is “solid” or fully inflated, is very heavy, but has wheels for easy transport, and has a retail price of $3,999 USD.
Figure 3 - Snap Attack football machine
The Heater Sports CR99 Crusher Curve Mini Lite Ball Pitching Machine can train your eye to hit a ball approximately two-thirds smaller than a real baseball. With the Crusher's Dual
The product objectives were met wherever possible. Customer specification changes caused the deviations noted above in bold.
A list of the engineering characteristics and associated importance is below in Table 1. These characteristics can all be quantified and will be adhered to as closely as possible throughout the design process. These characteristics show that ease of use, safety, and cost are the most important characteristics; with cost having the highest relative importance.
Table 1 – Engineering Characteristics Engineering Characteristics Quantitative Measures Relative Importance Speed of motor RPM 5% Angle of launching wheels Degrees 5% Height of body off of ground Inches 5% Operation switches Yes/No 10% Warning labels Yes/No 5% Safety guards Yes/No 15% Costs less than $250 Yes/No 20% Set-up time <5 minutes 5% Weight <35 lbs. 15% Stability of base ≥24” base 15%
Concept Design #2: Three belts
Figure 7 – Concept #
This design concept uses three linear belts driven by multiple motors. All belts make equal contact with the ball. The pro of this design is that the ball has a consistent and straight path. The cons are that there is no spin on the ball and the path of travel cannot be adjusted.
Concept Design #3: Two Belts Advancing, One Belt Lateral
Figure 8 – Concept #
This design concept uses two advancing belts and one lateral belt below the ball plane. This gives the ball forward motion while also putting spin on it. The belts will be driven by two motors; one for the two advancing belts and a second for the lateral belt. The pros of this design are that the ball is thrown with a spiral and in a consistent path. The cons are that this design is more complicated to manufacture and that it has more pinch points.
Figure 9 – Isometric View of Model
Figure 10 – Overall Height
A projectile motion calculation was performed at three intervals of throwing distance. This shows the approximate velocity, angle, height, and time of a throw at each distance. 5, 15, and 25 meters represent the approximate min, mid, and max distances respectively.
Due to design specification changes the angle of launch and distance thrown have changed. See the Design Analysis section of this report for more details.
𝑎 =
V𝑓 − V 0
t
Using a mass of ~5.5 oz for nerf football 5.5 oz. =156G =.156kg
𝑓 = m x a
𝑓 = .156 x 6.74 = 1.05𝑁
𝑓 = .156 x 6.70 = 1.05𝑁
𝑓 = .156 x 6.73 = 1.05N
Note: 1.05N = 0.236 lbf
Figure 12 – Pigtail, Switch, Wheels
The Nerf Football Launcher was load tested with 150 lbs. of mass on the top surface. This was to simulate a child climbing on the machine. Since the average weight of a ten year old child is 70.5 lbs. the safety factor is 2. After the presentation at the 2015 Tech Expo the machine was impact tested. The machine was dropped from a height of 2 feet onto a blacktop surface. There was minimal cosmetic damage to the wood paneling and no noticeable loss of structural integrity. The football launcher was powered on and fully operational after these tests. Additionally, the machine was designed to have a square base and be lightweight (actual weight is 23 lbs.). This base greatly reduces the risk of tipping. The lightweight design permits easy mobility (prevents minor injury) and should prevent serious injury if a child somehow tips the machine over onto themselves.
Figure 13 – Load Testing
