;tc mechanical engineering technology

Powered Car Lift for Low Ground Clearance Vehicles

by

PATRICK MERCADO

Submitted to the MECHANICAL ENGINEERING TECHNOLOGY DEPARTMENT

In Partial Fulfillment of the Requirements for the

Degree of

Bachelor of Science In

MECHANICAL ENGINEERING TECHNOLOGY

at the

College of Applied Science University of Cincinnati

May2007

© ...... Patrick Mercado

The author hereby grants to the Mechanical Engineering Technology Department permission to reproduce and distribute copies of the thesis document in whole or in part.

Signature of Author

Certified by

Accepted by

Mechanical Engineering Technology

;tc ~ ,AJ2Q_ ~-Laura Caldwell, Thesis Advisor

n~&Y~ r. Muthar AI- ba1d1, Department Head Mechanical Engineering Technology

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ABSTRACT Owing low ground clearance vehicles can have some disadvantages, such as the difficulty in servicing from underneath. Plastic car ramps currently available at auto service stores cannot accommodate these lowered vehicles. While there are car ramps that can be specially ordered, they are too long to fit into a standard trunk space. To gauge the interest for a Powered Car Lift for Low Ground Clearance Vehicles surveys were handed out to possible customers. The surveys asked the customer to rate the current tools on the market for servicing cars versus a proposed powered car lifting device. From the survey evolved product features that the customers wanted. The features were taken into consideration when the design phase started. The design phase included alternative designs, loading conditions, scheduling, stress concentrations, factors of safety, a proposed budget and materials selection. The information gathered from the design phase was incorporated into the manufacturing of the device which included cutting, welding, measuring, and the final assembly of the product. During this phase set backs were encountered due to machine error and human error. Next testing was done on the fully assembled product using a conventional car. Testing was done to prove that the product features that the customers wanted were incorporated into the final product. Off centered loading was done to simulate real world conditions. When all of the testing was done the proposed schedule was compared to the actual schedule it took to design, build, and test the product to see where improvements could’ve been made. The same goes for the budget. The actual and proposed budgets were compared to gain an understanding on what it really takes to create a suitable budget for a project.

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TABLE OF CONTENTS ABSTRACT .........................................................................................................................................................II LIST OF FIGURES ........................................................................................................................................... III LIST OF TABLES ............................................................................................................................................. III INTRODUCTION ................................................................................................................................................ 1 FEATURES AND CUSTOMER FEEDBACK .................................................................................................. 4 DESIGN ................................................................................................................................................................. 4 FABRICATION AND ASSEMBLY ................................................................................................................... 7 TESTING AND PROOF OF DESIGN ............................................................................................................... 9 PROJECT MANAGEMENT ............................................................................................................................ 10 CONCLUSION ................................................................................................................................................... 10 REFERENCE ..................................................................................................................................................... 11 APPENDIX A – EXISTING PRODUCTS ...................................................................................................... A1 APPENDIX B – SURVEY ................................................................................................................................ B1 APPENDIX C – CUSTOMER FEATURES & ENGINEERING

CHARACTERISTIC DEVELOPMENT TOOL ............................................................................................ C1 APPENDIX D – AIR BAG ENGINEERING DESIGN SPECIFICATIONS ............................................... D1 APPENDIX E – DETAILED DRAWINGS AND DIMENSIONS ................................................................. E1 APPENDIX F – CALCUALTIONS ................................................................................................................. F1 APPENDIX G - CUSTOMER REQUIREMENTS & PRODUCT OBJECTIVES ..................................... G1 APPENDIX H– SCHEDULE ........................................................................................................................... H1 APPENDIX I – BUDGET .................................................................................................................................. I1 LIST OF FIGURES Figure 1 – Raising (Jacking) the Car Process .................................................................................................... 1 Figure 2 –Low Angle Plastic Car Ramps ........................................................................................................... 2 Figure 3 –Scissor Lift ........................................................................................................................................... 2 Figure 4 –Add-On Plastic Ramps ........................................................................................................................ 3 Figure 5 –Motorized Car Jack ............................................................................................................................ 3 Figure 6 –General Double Convoluted Air Bag ................................................................................................. 5 Figure 7 –Powered Car Lift Expanded ............................................................................................................... 6 Figure 8 –Top and Bottom Linkage System ....................................................................................................... 7 Figure 9 –Assembly Stages................................................................................................................................... 8 Figure 10 – Compressed Height .......................................................................................................................... 9 Figure 11 –Trunk Storage .................................................................................................................................... 9 Figure 12 –Extended Height .............................................................................................................................. 10 LIST OF TABLES Table 1 - Variation in Existing Products ............................................................................................................ 2 Table 2 – Weighted Decision Chart .................................................................................................................... 5

Powered Car Lift For Low Ground Clearance Vehicles Patrick V. Mercado

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INTRODUCTION One of the most popular modifications that can be done to a car is to lower the vehicle’s ride height. By modifying the car the driver can possibly improve the styling and handling of the car. There drawback to modifying these cars stems from the fact that it’s hard to use the current market’s tools to service the modified cars. The conventional step by step process of jacking up a non-modified car can be seen in Figure 1. The process uses tools that were available on the current market. With a low ground clearance vehicle certain steps of the process would be hard to complete.

The first step is to park the car on level ground and engage the parking brake. Leave manual transmission cars in first gear or reverse and put automatics in park.

The next step is to place a chock or a brick behind or in front of (depending on the road's incline) the wheel diagonally opposite the one being jacked up.

The third step is to place the jack under the car's frame nearest the wheel to be jacked up. There's a thin [1

Step four occurs when the jack is in place, insert the handle according to the directions on the jack, and turn or ratchet the handle to make the jack rise. If it lowers or cannot turn, rotate the handle the other way, or flip the switch marked 'R' and 'L' (for 'raise' and 'lower').

] lip that runs along the side of your car. This is where the jack should go. Your owner's manual will have a picture of the safest place to put the jack. Bumper jacks will

attach to slots in the front or rear bumper (on older cars).

[1]

The fifth step is to raise the jack high enough to either replace a flat tire or place the car on a jack stand (a sturdy temporary stand at a fixed height). If you're changing a flat, remember to leave extra room the new tire will be full of air.

[1]

The final step was to lower the jack when finished. Be cautious and go slowly. If you've used a jack stand, before lowering the jack you will need to raise the car slightly to pull the stand from its place.

[1]

Figure 1 – Raising (Jacking) the Car Process


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There are many tools and equipments available to the home mechanic to service their vehicles. Two of these tools were compared in Table 1.The table showed the price for each product and how much lifting capacity the product produced. There are many other products on the market and these are just an example of two that are available to anybody who works on their car. Table 1 - Variation in Existing Products

There are a wide variety of existing items that can be used by the car consumer to perform services on their vehicles. The plastic car ramp was the most common and widely used apparatus. A picture of what these ramps look like can be seen below in Figure 2. There are a few good things about these ramps. First of all they are made from a solid piece which makes them very sturdy and durable. The low angle plastic car ramps are also made from plastic which makes them light weight. Even though the ramps are made from plastic they can handle a load of 1200 pounds per ramp. The ramp does have its downfall. The ramp is 12 inches by 56 inches which is not compact enough to fit into a standard trunk space. They also take up room in a garage space. More details about the ramps can be seen in Appendix A.

[2] Figure 2 –Low Angle Plastic Car Ramps

There are also scissor lifts available to use when servicing a car. The device was placed underneath the car so it corresponds to the lifting points of the vehicle. The good thing about using this scissor lift was that it has a lifting capacity of 6000 pounds. The scissor lift had two automatic safety locks. The problem with using the scissor lift was that it’s bulky and cannot be transported in a trunk. Also if the lines break the hydraulic fluid will be spilled everywhere. More specifications can be seen in Appendix A and the scissor lift can be seen in Figure 3.

[3] Figure 3 –Scissor Lift

Race Ramps Scissor Lift

Initial Cost $ 189.99 [2] $ 995.00 [3]

Capacity 1200 pounds per ramp [2] 6000 pounds [3]


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Another device that was available to the car enthusiast was an add-on piece that was used in conjunction with a set of specific ramps. The ramps were made from ABS polymers which mean that they will not rust. A good feature about these ramps was that they were cheap. The ramps were strong enough to support a vehicle that weighted 4000 pounds. One bad feature about the ramp was that it will only work with a compatible steel ramp. A picture of the plastic add on ramps can be seen in Figure 4 and in also in Appendix A.

[4] Figure 4 –Add-On Plastic Ramps

Another common device available to the car enthusiasts was the motorized jack. This device used the car battery to run a motor attached to jack. The purpose of this device was so that the consumer didn’t have to do the work of cranking the jack to raise and lower the car. The motorized jack had a few good features. One of the features was that it’s only 10 pounds. The user had to perform no actual manual labor. Finally the motorized jack had a lifting capacity of 2200 pounds. The feature that made the motorized jack undesirable was that a jack stand was still needed when working underneath a vehicle. Also it tood twice the time to get either front or back wheels off the ground with only one motorized jack. A picture of the motorized car jack can be seen in Figure 5 and also in Appendix A.

[5] Figure 5 –Motorized Car Jack


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FEATURES AND CUSTOMER FEEDBACK To ascertain if the powered car lift would be of interest to the market a survey was constructed. The survey had a series of 22 questions that asked the surveyor to rate the current tools on the market to service cars and what features they wanted to see in the prototype of a powered car lift. The survey was placed in several car forums for anyone interested to give their opinions and complete the survey. The survey was also passed out to people in school who work on their own cars. Finally the survey was also passed along to friends and family who work on cars. The people who took the surveyed ranged from teenagers to adults. There were also one on one interviews conducted to determine the interest in a powered car lift for low ground clearance vehicles. From all of the surveys distributed to the public 16 were completed and returned. The survey data was put into a product development tool to produce features ranging from the highest importance to the lowest. The top three features were safe, dependable and heavy duty. The product development application was used to determine what kind of tools, materials, and procedures would be needed to answer the customer’s wanted features. For example one of the customer requirements was that the prototype lift should be compact. From the product development application an engineering characteristic that will make the prototype compact was to manufacture it in a way so that the overall geometry/shape was small in size. The product objective to solve the problem would be to design the prototype so that the whole assembly was small enough to fit into a standard compact car trunk. A complete diagram of the product development application can be seen in Appendix C. DESIGN In designing the Powered Car Lift there were questions that had to be answered. What type of automobile will the prototype lift? How low does the car have to be before the lift was ineffective? What was the average trunk space volume? How high will the Powered Car Lift raise the car? How will safety be incorporated into the design? These are but a few of the questions that had to be answered during the design sequence. Also some of the design standards for car jacks, car ramps and jacks stands were incorporated into the design of the Powered Car Lift. To power the lift there were two possible power sources. One power source considered was hydraulics and the other was pneumatics. Each source had their pros and cons. To use hydraulics a reservoir was needed to hold the hydraulic fluid. A pump was also needed to run the hydraulic fluid from the reservoir to the cylinders. If there was a hydraulic fluid leak clean up was needed. But hydraulics did have a lot of pushing force. On the other hand, using pneumatics with air bags as a power source also had some enticing characteristics. For example there are no fluids needed when pneumatics was used because air was the only thing running through the lines. With having only air in the lines a possible leak wouldn’t affect the surrounding environment. Air compressors are readily available at any home improvement store. Also with the use of air bags, pneumatics also had a strong pushing force. The pros and cons of the two power sources were used in a weighted decision chart. The weighted decision chart was a tool to help determine which power source was the best fit for the application of a Powered Car Lift for low ground clearance vehicles. The weighted decision chart also took into account the survey that was handed out to potential customers. Each feature on the survey was assigned a relative weight that came from the product development application that can be seen in Appendix C. Then the two power sources were given a rating that ranged from 0 being bad and 4 being good based on how they lived up to each of the 11 survey features. The relative weight was then multiplied by the rating to produce a numerical value. In the end the numerical values for


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the pneumatics and hydraulics were summed up. According to the weighted decision chart the best power source to go with was pneumatics. Hydraulics was not too far behind from being chosen as the power source. The closeness of the decision can be seen in the Table 2. Table 2 – Weighted Decision Chart 4 = Good0 = Bad

Relative W eight Pneumatics HydraulicsSafe 0.13 3 0.392 3 0.392Dependable 0.12 3 0.374 2 0.249Heavy Duty 0.10 4 0.413 4 0.413Adaptable to any car 0.09 3 0.269 3 0.269Compact 0.09 3 0.263 3 0.263Cost Effective 0.09 3 0.282 2 0.188Light weight 0.08 4 0.340 3 0.255Portable 0.08 4 0.313 3 0.235Easy to use 0.08 3 0.243 3 0.243Easy to set up 0.08 3 0.231 3 0.231Pleasing to the eye 0.05 3 0.146 2 0.097

3.267 2.836 Designing the powered car Lift for use with a standard sedan, a maximum allowable weight needed to be found. Through research a 2006 Cadillac CTS-V V8 was chosen because the car weighed approximately 4500 pounds. An average sedan would be safe to use on the power lift since the maximum allowable weight was greater than the average weight of a sedan. Approximating that 75% of the Cadillac’s weight was in the front of the car because it was a front engine car; the weight over the front axle was 3375 pounds. Having chosen the wheel as the lifting point, the maximum load per powered car Lift was 1688 pounds. With pneumatics having been the chosen power source and a maximum load of 1688 pounds per Powered Car Lift an air bag manufacturer was researched. Firestone Airstroke Actuators were the best fit for this type of application. Firestone’s Airstroke Actuator Double Convoluted Model # 20 was chosen because of the abilities and traits it possessed. For instance at an extended height of 8 inches and with a pressure of 100 psig running into the bag , it had a pushing force of 3030 pound force. With having the need for an air bag that could handle at least 1688 pound Model #20 with 3030 pound force was perfect for the powered car Lift. Also since the bag compressed to a height of 3 inches it would’ve fit virtually any stock or lowered vehicle with a ground clearance of 5 inches. With using the Model #20 an extended height of 9 inches from the ground to the top of the platform was reached. Having such a tall extended height gave the customer ample room to work underneath the car. A general double convoluted air bag can be seen in Figure 6. A more detailed engineering specification sheet that came from the manufacturer of the air bag can be seen in Appendix D.

[6] Figure 6 –General Double Convoluted Air Bag


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The process for using the powered car Lift started when the user took both lifts out of storage. The storage place was either a garage corner or out of the trunk of a car. Next the user proceeded to place each lift in front of the wheels taking care to situate the ramps in the center of each wheel. The customer would then attach the air lines to each air bag. The other end of the air line was then attached to the shop air compressor or a portable pull along air compressor. The car was then driven slowly onto the ramps and onto the platforms. The engine was turned off and the emergency breaks were applied. The customer then checked to make sure that the tire was situated on the center of the platform. When he or she were satisfied with the placement of the tire then they proceeded with turning on the inlet valve to allow air into the bags. The bags will inflate at the same time if the lines coming from each air bag into a T-Valve and out to the air compressor was of equal length. When the bags had expanded to it full extension with the help of built in mechanical stops the user placed ball lock pins into certain locations of the top link and through a block of metal. The pins held the platform in place if there was some catastrophic bag deflation. The pins gave the user time to get out from underneath the vehicle. The pins were also used incase some one accidentally deflated the bag while a user was underneath the car. When they were done servicing the vehicle then the whole process was reversed. Before starting the calculations for the lift the type of loading had to be assessed. Since the wheel of the tire only rested on the platform which produced vertical loading the system was only carrying static loading. According to the book “Applied Strength of Materials” by Robert Mott systems with static loading must use a safety factor of 2. The way the wheel was resting on the platform can be seen in Figure 7.

Figure 7 –Powered Car Lift Expanded

Calculations were done on the linkages because they would carry the entire load if the bags were to accidentally deflate. Reasonable linkage dimensions were chosen for the calculations. There was

1688 pounds of load on the lift


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12 links that made up a total of 6 linkage system. Since the load being carried by each lift was 1688 pounds, each of the 6 linkage system carried 281 pounds. The linkage dimension was 6.48 inches long, 1.25 inches wide and 0.25 inches thick. To make the powered car lift small enough to fit into a standard sedan trunk an overall dimension of 20 inches by 15 inches was used as a dimensional criterion. Detailed drawings of the linkages, frame and ramps of the powered car lift can be seen in Appendix E. A drawing of the linkage system with assigned lettering notations can be seen in Figure 8. The top linkage BAC had three holes with diameters 0.25 inches and the bottom linkage CD had two holes with diameters 0.25 inches. At point A was where the ball lock pins would go through. At points B and D was where the linkage was riveted to the top and bottom frame. Point C was the connecting point for the top and bottom linkage. Having taken into account the dimensions of the linkages and the loads being carried by the linkages the highest bending moment was at point A with 1308 pounds inches. Point A also carried the highest stress concentration of 24327 pounds per square inch. For complete and detailed calculations see Appendix F.

Figure 8 –Top and Bottom Linkage System

Having known the amount of stress concentration occurring in the linkages a suitable material needed to be picked. Taking into account availability and price Cold Drawn 1018 Steel was chosen to be the linkage material. Cold Drawn 1018 had a yield tensile strength of 53700 pounds per square inch. The yield tensile strength and the design factor for static loading produced a static bending stress of 26850 pounds per square inch. When the static bending stress was compared to the stress concentration it yielded a safety factor of 1.1. Having a safety factor of 1.1 meant that the linkage system wasn’t overly designed. For Point B and C a 0.25 inch diameter 18-8 Stainless Steel Blind Rivets were used because they had a shearing force of 1700 pounds which was higher than the amount of force being exerted at the specified points. For Point D a 0.25 inch diameter Zinc-Plated Steel Blind Rivets were used because they had a shearing force of 1245 pounds which was able to handle the load being applied at that point. A Zinc-Plated T-Handled Ball Lock Pin was used at Point A for safety because each pin had a Single Shear Strength of 4320 pounds. There were 4 of the pins at each Powered Car Lift. As for the ramp 6061 Diamond Plate Aluminum was used because it was lightweight and strong. Complete and detailed calculations can be seen in Appendix F. FABRICATION AND ASSEMBLY The machine shop located in the North Lab of the College of Applied Science was used for the majority of the fabrication and assembly during the time span of 3/19/07 to 5/09/07. The tools and machines used in the fabrication stage were the horizontal band saw, the vertical band saw, the vertical mill, the drill press, the chop saw and the MIG welder. Measuring twice and cutting once was a key factor in the fabrication stage because improper measurements had led to misalignment of the parts which caused delays in the assembly stage.


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The linkages for the lift came from a rectangular flat bar. The lengths were measured twice and cut with the chop saw. The links were then taken to the grinder to get the precise length. The corners of the flat bar were cut and were also taken to the grinder to get a radius at each end of the link. The holes were properly marked using lay out die and a hole punch. Marking the placement of the holes had made it easier when drilling the holes. The top and bottom frames came from square tubing which measured 1.25 inches tall by 1.25 inches wide with a wall thickness of 0.120 inches. The tubing was cut to length and the ends were mitered to a 45 degree angle. The ends were mitered so that they yielded a perfect square when assembled. The top plates/platforms were already cut to size when they were ordered. The ramps were measured to length and cut with a vertical band saw. The mechanical stops which were in a shape of a trapezoid were also cut from a rectangular flat bar. The overall dimensions of the mechanical stops were crucial because they not only prevented the air bag from over inflation, but they also dictated the height and level of the platform. The stage of assembly began with putting the already cut square tubing into a jig so that they could be welded together using a MIG welder (1). The next step was to do a test fit of the linkages on the mechanical stops (2). The linkages were also riveted together and drilled at this stage. The top plate/platform was welded to the top frame using a MIG welder (3). The holes for the rivets were marked and drilled on the top frame at this stage. Next the mechanical stops were welded to the top platform and the ball lock pins were fit tested (4). The bottom frame was marked and drilled for the blind rivets and for attaching the air bags to the top and bottom platforms. The air bag was placed within the lift so that it could be tested for clearance (5). The final steps of the assembly was to paint the powered car lift OSHA yellow, put grease between the linkages and rivets, attach grip tape to the ramp for added traction, and tighten all of the fitting (6). For detailed drawing of the parts see Appendix E.

Figure 9 –Assembly Stages

There were a few set backs during fabrication and assembly. The machines in the North Lab couldn’t hold tolerance which meant 100% accuracy was hard to accomplish. The saw didn’t always cut straight which wasted time and materials. Not having the correct amount of materials also caused delays. With the problems in fabrication and assembly the only event that changed on the schedule was that demonstration was pushed back to the following week.

1 2 3

4 5 6


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TESTING AND PROOF OF DESIGN Testing needed to be done to prove that the Powered Car Lift not only worked on paper but also in the real world. Since a 2006 Cadillac CTS-V was not readily available, a stock 1997 Honda Civic LX was used. This was an appropriate substitution because part of the target customer was the import market. The first step in the test was to get the vehicle on level ground. Next the powered car lift was placed in front of the wheels. The hoses were connected to one another and to the fittings. The main air line was attached to a Craftsman 7 gallon pull along air compressor. The car was then driven on the ramps and on top of the platform. The engine was turned off and the emergency breaks applied. The car was deliberately not placed on the exact center of the platform. This was done so that it simulated the real world. Not everyone will be lucky enough to get the center of the platform every time. The exit valve was shut off and the inlet valve opened letting 90 pounds per square inches of air to flow into the air bags. The car was raised and lowered several times to insure that there were no binding within the linkages and that the air bags could handle continuous operations with load. The next step involved raising the platform to the highest level and then inserting the ball lock pins through the top linkage and through the mechanical stop blocks. Some of the air was released from the bag to test if the pins would be able to hold the load of the vehicle. The results from the testing were very promising. First even with the tire not being centered on the platform the powered car lift was still able to perform its function. When the air bags started to fill with air the platform looked uneven and not stable, but when the top platform reached the mechanical stop it completely leveled out perfectly. When the ball lock pins were inserted and the some of the air released the pins were able to hold the weight of the car. The pins couldn’t be pulled out of the holes while some of the air was released. This was a positive because as a safety precaution the pins stopped the platform from prematurely lowering while a person was underneath. Finally there was ample room to work and move around underneath the car while the platform was in full extension. The proof of design objectives which can be seen in Appendix G were all completed except one. The only objective not met was that it was a little too heavy. It was to be compared to a 3 ton floor jack but it was also suppose to be portable. The objective of meeting a compressed height of 5 inches could be seen in Figure 10. The objective of being compact enough to fit into a trunk was completed and can be seen in Figure 11. An extended height of 9 inches was reached and can be seen in Figure 12.

Figure 10 – Compressed Height

Figure 11 –Trunk Storage


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Figure 12 –Extended Height PROJECT MANAGEMENT With projects of any type, scheduling was always one of the issues. On this project it wasn’t any different. Certain tasks took longer than other to finish. For example during the winter quarter the task of coming up with designing and drawing the prototype lasted longer than scheduled. The task lasted longer due to the fact that safety was such a big feature on the product that it couldn’t be just set aside for a later date. Many prototypes were conceived, but only one could pass onto the next stage. Also in spring quarter delays with the materials not being available and machines not holding tolerances pushed back the demonstration was a week. With all of the issues the proposed schedule was really close to that of the actual schedule. There were no major deviations between the schedules. The actual schedule can be seen in Appendix H. There were two budgets, one was proposed and the other was the actual budget. In the beginning a proposed budget of $675 was set. This was based on preliminary observations of what was needed to manufacture the Powered Car Lift. When the whole project was completed an actual budget of $691.63 was achieved. With only having a deviation of $16.63 was a good sign of proper planning. Granted the actual budget would’ve higher if it weren’t for the generosity of some people. A detailed view of the proposed bill of materials and the actual bill of materials can be seen in Appendix I. CONCLUSION In the end this became a great and useful product. According to comments by spectators in Tech Expo they wished that they had a product like the Powered Car Lift for Low Ground Clearance Vehicles. Many liked the core concept behind the design. There are a few recommendations that would make the product more consumer friendly. First of all some of the steel should be substituted for aluminum so as to reduce the weight of the overall assembly. More engineering should be done on the entire assembly so that the compressed height of the lift can be greatly reduced to accommodate even lower vehicles. More engineering should be done on the design so that the lift can handle vans or trucks. The ramp’s angle of approach should be lower so that it’s easier to get onto the platform. The ramp should also be on hinges so that it can be folded up to make the overall dimension smaller. Finally the design of the Powered Car Lift for Low Ground Clearance Vehicles should be patented so as to protect the designer.


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REFERENCE 1 How to Jack Up a Car Safely [on-line manual] http://www.ehow.com/how_1864_jack-car-safely.html 11/14/06 2 “Car Ramps - Oil Change - Low Profile Cars,” [Online Catalog], [Cited September 29, 2006], http://www.amazon.com/Car-Ramps-Change-Profile-Cars/dp/B000AOO0MK 3 “Titan 6,000 LB Mid Rise Scissor Lift - 48" Ht.” [Online Catalog], [Cited on September 29, 2006], http://www.excel-equipment.com/catalog/product_info.php?products_id=893 4 “SAFE, "LOW-PROFILE" RAMPS,” [Online Catalog], [Cited September 29, 2006], http://www.griotsgarage.com/catalog.jsp?L1=L1_3000&L2=L2_3030&SKU=10144 5 Don't break your back, get the 12V Auto Jack!,” [Online Catalog], [November 8, 2005], http://www.sportsmansguide.com/cb/cb.asp?a=193887 6 “Airide Definitions,” [on-line manual] http://www.airsprings.com.au/Airide_Definitions.cfm 3/09/07

http://www.ehow.com/how_1864_jack-car-safely.html�

http://www.ehow.com/how_1864_jack-car-safely.html�

http://www.amazon.com/Car-Ramps-Change-Profile-Cars/dp/B000AOO0MK�

http://www.excel-equipment.com/catalog/product_info.php?products_id=893�

http://www.griotsgarage.com/catalog.jsp?L1=L1_3000&L2=L2_3030&SKU=10144�

http://www.sportsmansguide.com/cb/cb.asp?a=193887�

http://www.airsprings.com.au/Airide_Definitions.cfm�

Appendix A1

APPENDIX A – EXISTING PRODUCTS “Car Ramps - Oil Change - Low Profile Cars,” [Online Catalog], [Cited September 29, 2006], http://www.amazon.com/Car-Ramps-Change-Profile-Cars/dp/B000AOO0MK

• Light weight but strong, a pair holds up to 2400 lbs.

• Will accommodate sports car tires up to 10 inches wide

• Will not damage your hot asphalt, cement, or painted floors of your garage

• Built of one solid piece making them durable and sturdy

• Low Profile car ramps are ideal for use with low ground clearance vehicles like

Corvettes

• One piece unit • Strong • Low angle of slope • Multi-car purpose use

• Too long and not compact • Made of plastic • Max height is only 8”

http://www.amazon.com/Car-Ramps-Change-Profile-Cars/dp/B000AOO0MK�

Appendix A2

“Titan 6,000 LB Mid Rise Scissor Lift - 48" Ht.” [Online Catalog], [Cited on September 29, 2006], http://www.excel-equipment.com/catalog/product_info.php?products_id=893

Titan 6,000 LB Mid Rise Scissor Lift - 48" Ht. Mid-rise models lift cars, vans and light-duty trucks. They are ideal for tire, wheel and brake related repairs, collision repair work and new car preparation. * 6,000 lb. lifting capacity * Portable trolley supports pump and moves lift * Twin hydraulic cylinders and scissor lift design for maximum strength and stability * Easily adjustable sliding radius arms * Automatic two-position safety locks * Swivel pads come standard. Optional drop-in height adapters are also available * Overall width - 39 5/8”/ 65” * Overall length - 96 1/2” * Maximum height - 48 1/2”/ 54” * Lifting speed - 40 sec. * Motor - 1hp/110 vac * Collapsed height - 4 3/4” * Shipping weight - 950 lbs. * Warranty - 5 Year

• 6000 lb lifting capacity • Safety Locks • 5 year Warranty

• Doesn’t look too safe • Shipping weight 950 lbs. • Too bulky • Not portable

http://www.excel-equipment.com/catalog/product_info.php?products_id=893�

Appendix A3

“SAFE, "LOW-PROFILE" RAMPS,” [Online Catalog], [Cited September 29, 2006], http://www.griotsgarage.com/catalog.jsp?L1=L1_3000&L2=L2_3030&SKU=10144

Finally, a set of ramps that even a low-slung Mazda Miata can drive right up on! Whether you're changing oil or just detailing your undercarriage, these steel ramps provide safety while working underneath your car. The deep side rails help to keep your tires centered on the ramp, and the gradual incline takes the drama out of driving up on them. With 7 1 ⁄2" of overall lift of the vehicle, the 9 1⁄2" wide pair of steel ramps will support 4,000 lbs. of vehicle weight. The extension kit, made from tough ABS polymer, extends the ramp length by 15 inches, allowing maximum clearance for vehicles—even ones with low front ends. If you already have a pair of these steel ramps (1993 and later) and would like to convert them to the ultra low-profile ramps, just order the Extension Kit. Made in the U.S.A. Enjoy safety! (Ramps are an additional $10.00 for shipping).

• Adaptable to older ramps • Claims to be safe • Allows for good clearance • Cheap

• Made of ABS polymer • Still have to buy a steel ramp

http://www.griotsgarage.com/catalog.jsp?L1=L1_3000&L2=L2_3030&SKU=10144�

Appendix A4

“Don't break your back, get the 12V Auto Jack!,” [Online Catalog], [November 8, 2005], http://www.sportsmansguide.com/cb/cb.asp?a=193887

With the easy push-button operation using the remote control, you're safely away from the vehicle

while lifting and lowering.

• Simply plugs into your cigarette lighter for quick and easy power • 122" power cord from remote to cigarette lighter to easily reach any tire • 48" power cord from remote to jack • Lifting range of 6-13 1• 2,200 lb. capacity

/2"

• Heavy-duty steel construction • UL-listed • 15 1/2 x 6 1

/8" w., 10 lbs.

• Can only jack up one side at a time

• Will not work if car battery is dead

• Doesn’t seem to have a strong/ stable base

• Good lifting range • Plugs into cigarette lighter • Only weights 10 lbs. • UL-listed

http://www.sportsmansguide.com/cb/cb.asp?a=193887�

Appendix A5

Interviews:

From the period of January 2006 to October 2006 random people were interviewed about the idea of having an automated lift for low ground clearance vehicles. The interviews were conducted informally. No records were kept of the conversation, only side notes were taken down.

Side notes:

• The people wanted something that would work with any type of vehicle. • The future customers wanted something better than using wooden planks to drive up onto. • The customer also wanted the product to be safe.

Appendix B1

APPENDIX B – SURVEY

Please take a few minutes to answer the following questions to help me better my design.

Please circle the appropriate answer. 1 = low importance 5 = high importance

1 Safe 1 2 3 4 5 N/A 79 11.50% 4.9

2 Compact 1 2 3 4 5 N/A 59 8.59% 3.7

3 Light Weight 1 2 3 4 5 N/A 53 7.71% 3.3

4 Portable 1 2 3 4 5 N/A 54 7.86% 3.4

5 Adaptable To Any Car 1 2 3 4 5 N/A 66 9.61% 4.1

6 Easy To Set Up 1 2 3 4 5 N/A 58 8.44% 3.6

7 Cost Effective 1 2 3 4 5 N/A 71 10.33% 4.4

8 Pleasing To The Eye 1 2 3 4 5 N/A 36 5.24% 2.3

9 Easy To Use 1 2 3 4 5 N/A 60 8.73% 3.8

10 Dependable 1 2 3 4 5 N/A 78 11.35% 4.9

11 Heavy Duty 1 2 3 4 5 N/A 73 10.63% 4.6Total 687 100.00% 3.9

Are you satisfied with the current methods and tools for servicing the front end of the car? Please circle the appropriate answer. 1 = very unsatisfied 5 = very satisfied

1 Safe 1 2 3 4 5 N/A 66 9.72% 4.1

2 Compact 1 2 3 4 5 N/A 59 8.69% 3.7

3 Light Weight 1 2 3 4 5 N/A 55 8.10% 3.4

4 Portable 1 2 3 4 5 N/A 60 8.84% 3.8

5 Adaptable To Any Car 1 2 3 4 5 N/A 64 9.43% 4.0

6 Easy To Set Up 1 2 3 4 5 N/A 65 9.57% 4.1

7 Cost Effective 1 2 3 4 5 N/A 66 9.72% 4.1

8 Pleasing To The Eye 1 2 3 4 5 N/A 49 7.22% 3.1

9 Easy To Use 1 2 3 4 5 N/A 65 9.57% 4.1

10 Dependable 1 2 3 4 5 N/A 68 10.01% 4.3

11 Heavy Duty 1 2 3 4 5 N/A 62 9.13% 3.9Total 679 100.00% 3.9

How much would you be willing to pay for an automated $50-$100, $100-$200, $200-$500car lift for low ground clearance vehicles? $500-$1000, $1000-$2000

Thank you in advance for taking the time to answer this survey. Your cooperation is greatly appreciated.

Comments:

I am a senior at the University of Cincinnati studying Mechanical Engineering Technology. I am in the process of designing an automated car lift for low ground clearance vehicles for my senior design project.

What is important to you for the design of an automated car lift for low ground clearance vehicles?

Powered Lift For Low Ground Clearance VehiclesCustomer Survey

Appendix C1

APPENDIX C – CUSTOMER FEATURES & ENGINEERING CHARACTERISTIC DEVELOPMENT TOOL 9 = Strong3 = Moderate1 = Weakno relation = blank

mat

eria

l

geom

etry

ass

embl

ey

pow

der c

oat p

aint

ing

Gov

ernm

ent C

odes

for T

rans

porta

tion

inte

rcha

ngab

le p

arts

mul

tiple

sup

plie

r of p

urch

ased

par

ts

repl

acem

ent p

arts

or a

bilit

y to

ser

vice

and

cle

an

cost

of m

anuf

actu

re

Cus

tom

er im

porta

nce

Satis

fact

on

Plan

ned

auto

mat

ed li

ft de

sign

Impr

ovem

ent r

atio

Sale

s po

ints

Impr

ovem

ent (

Abso

lute

wei

ght)

ratio

Rel

ativ

e w

eigh

t

Strength1. Heavy Duty 9 4.6 3.9 4 1.0 4.7 0.10Features2. Light weight 9 3.3 3.4 4 1.2 3.9 0.083. Adaptable to any car 9 4.1 4.0 4 1.0 4.1 0.094. Dependable 1 9 3 4.9 4.3 5 1.2 5.7 0.125. Compact 9 3 3.7 3.7 4 1.1 4.0 0.096. Portable 9 3.4 3.8 4 1.1 3.6 0.087. Safe 9 4.9 4.1 5 1.2 6.0 0.138. Cost Effective 9 4.4 4.1 4 1.0 4.3 0.09Ergonomics9. Pleasing to the eye 9 2.3 3.1 3 1.0 2.2 0.0510. Easy to use 9 3.8 4.1 4 1.0 3.7 0.0811. Easy to set up 9 3.6 4.1 4 1.0 3.5 0.08

Absolute Importance 2.5

3.20

0.44

1.18

0.12

1.12

0.37

0.85 45.7 1.00

Relative importance 0.25

0.33

0.04

0.12

0.01

0.11

0.04

0.09

Lifts on market

Direction of movement

Target Value

Units

9.76

Appendix D1

APPENDIX D – AIR BAG ENGINEERING DESIGN SPECIFICATIONS

Appendix E1

APPENDIX E – DETAILED DRAWINGS AND DIMENSIONS

Appendix E2

Appendix E3

Appendix E4

Appendix E5

Appendix E6

Appendix F1

APPENDIX F – CALCUALTIONS Calculations for the actual load per linkage system

( )

lbsLinkPerLoadMaximum

lbsLinkPerLoadMaximum

lbsPerWheelLoadMaximum

lbsWheelPerLoadMaximum

lbsLoadMaximumlbsLoadMaximum

25.28165.1687

5.16872

375,3

375,375.0*500,4

=

=

=

=

==

1688 pounds of load on the lift

Appendix F2

Calculations for the forces acting on the bottom link CD.

( )

lbsF

F

FFy

FlbsFy

380

)19.42cos(6

16880168819.42cos(6

)cos(6

1688

=

=

=−=Σ

=

= θ

lbsD

lbsD

2816

1688

=

=

Appendix F3

Calculations for the forces acting on the top link CAB with respect to normal x and y.

lbsC

lbsBy

lbsBy

380

2816

1688

=

−=

=

lbsBx

Bx

BxCCBxByM

AxBxAx

CBxAxFx

AyCByAyFy

A

125231.1

16410197.652324.653)31.1(39.334

0)32.2)(81.47sin()56.2)(81.47cos()31.1()19.1(

1507255

0)81.47cos(

00)81.47sin(

−=

−=

=−−−−=−−−=Σ+↓

==+

=−+=Σ

==++=Σ

lbsAAyAx

150701507

===

lbsB

ByBx

12832811252

=−=−=

lbsC 380=

Appendix F4

Calculations for the forces acting on the top link CAB with respect to x’ and y’.

1117)81.47sin(1507'1012)81.47cos(1507'

189)19.42sin(281'208)19.42cos(281'

928)81.47sin(1252'841)81.47cos(1252'

378)38.84sin(380'37)38.84cos(380'

−====

−==−==

==−==

====

AxyAxx

ByyByx

BxyBxx

CyCx

lbsAylbsAx

lbsBylbsBx

lbsCylbsCx

1117'1012'

739'1049'

378'37'

−==

=−=

==

Appendix F5

Shear and Moment Diagram for top link CAB that shows the maximum moment. Shear (lbs)

Moment (lbs*in)

1308

378

-739

0

3.46 in

Appendix F6

Calculations for the static bending stress and the safety factor.

2

2

850,26

2

700,53

2

:

inlbs

inlbs

SyStressBendingStaticForDesign

Static

Static

=

=

=

σ

σ

σ

intindinw

inlbsMKp

25.025.025.1

*13081

=====

Distances from the edge of the link to the hole at point A.

4.3625.0125.0

===

KqinYpinYq

Stress Concentration from the center of the hole at Point A to the edge of the link.

( )

2

33

327,24

048,41.279,2025.0

'6

inlbsp

p

Axxtdw

MwKpp

=

+=

+

−

=

σ

σ

σ

Stress Concentration from the center of the hole at Point A to the edge of the hole at Point A.

( )( ) ( )

2

33

819,17

2.763,1382.055,4

25.0'6

inlbsq

q

AxxKqtdw

MwKpYpYqq

=

+=

+

−

=

σ

σ

σ

1.1327,24850,26

:

==p

FactorSafety

Static

σσ

Appendix G1

APPENDIX G - CUSTOMER REQUIREMENTS & PRODUCT OBJECTIVES

Customer Requirements Objectives

Safe ● The product will meet the ANSI codes for jack stands and floor jacks.

Dependable / It Will Work

● It will be able to operate using a normal 12 volt car battery and can also be plugged into a house socket. ● It will have an adaptor piece so that it can be used with the supplied air compressor and also a shop compressor. ● No binding will occur during operation.

Heavy Duty / Strong Frame

● It will be designed so that it can stand up to heavy use and will still be fully functional. ● The product will be constructed using a design factor of XX for static loading.

Adaptable ● The product’s design will allow for it to be used on any standard compact car including low profile cars.

Compact ● It will be small enough so that it can fit into the trunk of a compact car.

Cost Effective/ Low Maintenance

● It will be made from commercial parts so that when maintenance is needed, parts will be easy to obtain. ● The commercially bought parts will have a limited lifetime warranty either through the company that makes the product or the company that sells the product.

Light Weight / Easy To Carry, Portable

● The product can be broken down into five components for storage and transportation ● The handles will be sized for an adult hand, oriented for left and right grasping, and be in line with the center of gravity. ● It will weight about the same as a three ton hydraulic floor jack.

Easy To Use, Easy To Set Up

● There will have clear and easy to read name plates for buttons and color coded hoses. ● The product will only take XX minutes to get both the front, both the back, and front and back wheels off the ground. ● The product compressed is only XX inches. It will also be XX inches fully extended.

Pleasing To The Eye ● The parts will be painted in OSHA yellow and will have diamond plating.

Appendix H1

APPENDIX H– SCHEDULE

Powered Lift For Low Ground Clearance Vehicles Patrick Mercado Note: Tasks and Dates in RED are deadlines.

Winter Quarter Spring Break Spring Quarter

Dates 12/3

1-1/

6

1/7-

1/13

1/14

-1/2

0

1/21

-1/2

7

1/28

-2/3

2/4-

2/10

2/11

-2/1

7

2/18

-2/2

4

2/25

-3/3

3/4-

3/10

3/11

-3/1

7

3/18

-3/2

4

3/25

-3/3

1

4/1-

4/7

4/8-

4/14

4/15

-4/2

1

4/22

-4/2

8

4/29

-5/5

5/6-

5/12

5/13

-5/1

9

5/2-

5/26

5/27

-6/2

6/3-

6/9

6/10

-6/1

6

Tasks Weighted Objective Method Proof of Design 1/10/07 Design & Draw Prototype Design & Draw Prototype Design & Draw Prototype Calculate Design Calculate Design / Design Freeze 2/21/06 Calculate Design Oral Design Presentation 3/6/07 Design Report 3/14/07 Order Parts / Spring Break Build Entire Prototype Build Entire Prototype Build Entire Prototype Build Entire Prototype Demonstration 5/9/07 Correct problems Tech EXPO 5/16/06 Oral Presentation 5/29/07 Project Report 6/4/07

Appendix I1

APPENDIX I – BUDGET PROPOSED BILL OF MATERIAL

Budget

Brand Name Type Amount

Firestone Airstroke Actuator Air Bag (QTY = 2) $375Airline, Hose 1/2 inch Nylon Air Line Tubing ( $ 0.70 per feet) $20Air Management System Fittings, Ball Valves $30Metal Frame Square Tubing, 1018 Cold Drwan Steel $200Misc Parts/ Services $50

TOTAL $675

Appendix I2

Powered Car Lift For Low Ground Clearance Vehicles

Actual Bill of Materials Name / Description Quantity Unit of Measure Total

Square Tubing 1.25" X 1.25" X 0.120" 2 104" $77.48 Cold Drawn 1018 Steel 0.25" X 1.25" 2 84" $31.84

Metal Plate 13" X 13" X 0.25" 2 12 lbs $35.88 Square Stock 1.5" X 1.5" 1 48" $41.28

Cold Drawn 1018 Steel 0.25" X 1.5" 1 24" $8.16 Diamond Plate Al 6061 13"X 18" 0.25" 1 $20.00

Push Lock Union Tee 1 $8.87 1/4" NPT Male, Push Lock Female 2 $7.20

Male Elbow Swiv 1 $6.99 Plastic Ball Valve 2 $12.44

3/8" Air Line 1 300" $11.99 Firestone Airstroke Actuator Air Bags 2 $344.40

T-Handle Ball Lock Pins 8 $44.96 18-8 SS Rivets 1/4" Diameter 0.251"-0.375" 1 pack 25 per pack $13.86 18-8 SS Rivets 1/4" Diameter 0.376"-0.500" 1 pack 25 per pack $14.40 Zinc- Plated Rivets 1/4" Diameter 0.501"-

0.625" 1 pack 100 per pack $11.88 Grand Total $691.63

;tc mechanical engineering technology

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