Progress Report Maseeh College of Engineering & Computer Science Winter 2016 Kart 2 Design Team Atom Falcone Austin Greene Jesse Majoros Nick Vanklompenberg Jake Waterman Jeffrey Williamson Faculty Advisor Dr. Yi Sponsor Dr. Turcic
Executive Summary A kart stand enables kart racers the ability to safely unload, transport, repair, and load their kart at a racing event. Most weekend racers travel alone to and from the track. This raises the issue of how does one person safely move an awkward shaped 200 pound uneven load? The objective of the PSU Kart 2 Capstone Team is to design a reliable stand for kart racers that can raise/lower and transport the kart around any racing complex. The stand must attach to a standard trailer hitch receiver for safe & secure device transportation while the cart resides inside the transport vehicle. The design and prototype for the kart stand will be deliverable to Dr. Turcic in June of 2016. To date, the team has identified product design specifications (PDS), completed external/internal searches of existing products, and conducted group brainstorming sessions to develop and evaluate various concepts. After reviewing the design requirements for the deliverable project and meeting with the sponsor, the team scaled back from completing a finished stand to refining a set of plans and designs with a scaled prototype which can then be used by Dr. Turcic and the karting community. The team is currently in the detail design phase of product development. The key PDS defining points of the stand are its reliability and single person operation. Through our external search it was identified that there are existing solutions to the design requirements. The important search parameters included powered lifting, collapsibility, and safe single person operation. The team developed five concepts and evaluated them based on the PDS criteria. The chosen concept incorporates reliability through detailed engineering analysis, safety, battery powered winch, one person operable, and the ability to be transported via a trailer receiver. 1
CONTENTS Executive Summary.. 1 Introduction.....3 Mission Statement.... 3 Project Plan......4 Product Design Specifications.....5 External Search.... 6 Internal Search... 7 Design Evaluation/Concept Selection...8 Detail Design Progress.....9 Conclusion....9 References........XX Appendices.... XX 2
Introduction Kart racing is a variant of open wheel motorsport with small, open, four wheeled vehicles called karts. They are raced on scaled down demanding pavement circuits. The karts themselves weigh 200lbs and must be transported to the race complex by a transportation vehicle. A mechanism is needed to facilitate the moving of the kart to and from the transport vehicle and the raceway as seen below in Figure 1. For solo operations, this is made impossible by the awkward size and weight of a kart. Figure 1: Current stand with kart shown on typical terrain. Current off the shelf solutions are either expensive and or unstable. The client currently uses a solid stand with wheels which requires a minimum of two people to load and unload the kart from the stand. The current stand also does not facilitate ease of kart transportation because it requires two people to place the kart onto the stand. Thus, there exists a need for a reliable and stable stand which can assist the solo kart racer in transportation and storage of the kart. 3
Mission Statement The objective of the Portland State University (PSU) Kart 2 capstone team is to design a reliable single operator stand for kart racers that can raise/lower and transport the kart around any racing complex. The stand must attach to a standard trailer hitch receiver for safe & secure device transportation while the cart resides inside the transport vehicle. 4
Project Plan Table 1: Project plan major dates and deadlines. Figure 2: Gantt chart of milestones. 5
Product Design Specification Summary A detailed list of design requirements and specifications was created based on customer and group input as found in the PDS document in appendix A. Each design specification was prioritized and quantified as noted in the spreadsheet. To summarize the PDS document, the top level specifications are listed and explained below: Cost: The total cost of a full scale working product should be less than what is readily available on the market. External research and customer input has determined that the price of materials and fabrication should not exceed approximately $1000. The budget for our scale model is to be less than $600. Weight: The weight of the stand is important for mobility, ease of operation, and transportation. To meet all of these criteria, a target weight of less than 100 lb. has been set. Ability to stow: With limited space inside the customer's vehicle, the final design will be capable of attaching to a standard trailer hitch. Stability: The stability of the cart stand is crucial during all modes of operation. Calculations will be made to ensure stability during lifting and lowering of the cart, as well as static and impact loads. Reliability: The final design is intended to be 100% reliable throughout the life of its service, while also requiring minimal maintenance. Reliability of the stand is an important factor in the overall performance of the kart racer. If the stand fails at any time during a race day, the user s race performance will be put in jeopardy. Safety: Precautions will be made to ensure the safety of the end user throughout the design process. Areas of concern include pinch points, electric shock, stability, and sharp edges. The lifting mechanism will also include an emergency stop/start button to mitigate any accidents during the lifting/lowering action of the stand. One person operation: One of the main criteria defined by the customer is that the product should be able to be operated by a single person with ease. The customer currently uses a dependable stand, but requires more than one person to lift, lower, and unload the cart. Powered lift: In order to maximize the ease and safety of use of this stand, the customer requires the lifting mechanism to be fully powered. The stand will be able to lift the kart from the transportation vehicle or ground level to the fully upright position by the press of a button. 6
External Search The PSU Kart² capstone team reviewed existing kart lifting devices as well as some other compact lifting devices to develop a product that meets the PDS requirements. JEGS Performance Products JEGS Multi Purpose Lift JEGS multipurpose lift, shown in figure 3, is a lift used typically for motorcycles, ATV and golf carts. The lift has a lift height of 4.5 to 16.5. Due to the size of the wheels the lift would have trouble navigating diverse terrains. Due to the ground clearance of the a go kart the lift could not fit underneath to lift the kart. Figure 3: JEGS Multi Purpose lift is and off the shelf automotive lift. [1] KartLift Bigfoot KartLift s Bigfoot traditional stand, shown in figure 4, features large pneumatic tires for easy maneuverability. The stand folds for easy storage and transport. However this stand does not assist in lifting of the stand and would require two people to lift the cart onto the stand. Figure 4: KartLift Bigfoot stand shown in unfolded position.[2] 7
KartLift Winch Lift KartLift s WinchLift one person stand, shown in figure 5, uses a electric winch to lift the kart using hooks that attach to the back bumper. The stand costs upwards of $700 and can not be folded to stow more easily. Figure 5: KartLift WinchLift Stand shown in loaded position without a kart. Uses an electric winch to lift the kart. [3] Hepfner Racing Products Streeter Super Lift Hepfner Racing Products streeter lift, shown in figure 6, uses an electric winch to lift the kart similar to Kartlift s WinchLift stand. The stand is constructed from 1.25 steel tubing and uses a truss system making the stand weigh upwards of 150 lbs. Figure 6 : Hepfner Racing Products Super Lift stand. Lifts kart using an electric winch and frame consist of 1.25 steel tubing for a heavyweight stand. 8
Internal Search After surveying the commercially available solutions, our team went through the process of brainstorming to generate ideas and concepts which would successfully fulfill the PDS requirements set forth by the customer. The main PDS criteria that led the brainstorming phase was reliability, operability and storability. In order to accomplish the Top Level Design criteria, we determined that the main differences in our concepts was the way in which the lift was accomplished. Powered lifting can be accomplished by pivot lift, forklift or scissor lift. Preliminary static and dynamic analysis of operation was examined for each design. Reliability was determined in relation to moving parts and single user interface as well as complexity of lifting mechanism. Operability by a single person guided the designs decision regarding ergonomics and interface. Storability is a matter of modifying a stand to interface with a receive hitch, matters of size and weight dominated these decisions. Original project intent was to result in a full scale operable unit. After meeting with the sponsor and clarifying deliverables and goals, we revised the PDS to establish reflect the goals of a full theoretical model with analysis and instructions with the possibility of a scale prototype. 9
Design Evaluation and Concept Selection The three concepts developed in our internal search were distinguished primarily by the mechanisms in which the kart is lifted: scissor lift, winch lift and forklift, see appendix B. Our three concepts were compared along with the unfinished SOKS stand from a previous capstone team and the unpowered stand that is currently in use. The SOKS stand makes use of a lead screw as the drive system. The criteria used in the evaluation were: cost, weight, ability to stow, stability, reliability, safety, the ability to be operated by a single person, and the inclusion of a powered lifting mechanism; all of which were deemed essential criteria in the PDS report. The clear choice based on the design matrix, table 2 was the winch stand concept. The strength of the winch stand design is the compact and simple lifting mechanism. Of the lifting mechanisms considered the winch has the lowest cost and the lightest weight, and since the winch is compact and transmits its power via a flexible belt rather than through rigid members, the winch stand concept also has the greatest potential for folding into a smaller and more stowable form. Table 2 : Design matrix which includes the three concepts developed in the internal search, the unfinished SOKS stand from a previous capstone team, and the unpowered stand that is currently being used by the customer. Based on a 0 4 scale where 4 is the most desirable and 0 is the least desirable. Criteria Unpowered Cart Lead Screw (SOKS) Scissor Lift Winch Stand Fork Lift Cost 4 2 1 3 0 Weight 4 3 1 2 0 Ability to Stow 1 3 1 4 0 Stability 1 3 4 3 4 Reliability 4 1 0 4 2 Safety 0 1 1 3 3 One Person Operation 0 4 4 4 4 Powered Lift 0 4 4 4 4 Sum 14 21 16 27 17 10
Conclusion The Kart 2 team has concluded the PDS and finalized design decisions after having conducted both internal and external searches. After an evaluation of different concepts, a design was agreed upon that uses a similar frame to the SOKS kart and a powered winch as the drive system for lifting and lowering the kart. Thus far the team is on schedule as defined by the project plan, with the detailed designs to be complete early spring and ready for revisions. Having decided on the design, the next stage involves creating the detailed design plans, choosing specific parts/materials, 3D CAD drawing, finite element analysis, prototyping for a scale model, and performing analysis to verify the design specifications and customer requests have been met. The Kart 2 team feels confident in the design of the frame, being that it is the least complicated and there are many examples currently in the market to guide design choices. The main challenge moving forward will be the detailed design of the drive system. The key needs for a functioning drive system are safety and reliability. A large amount of analysis will go into confirming the choice for the drive system and insuring its reliability. 11
References: 1. "JEGS Performance Products W41035, JEGS Multi Purpose Lift JEGS Performance Products." JEGS High Performance Products. Web. 21 Feb. 2016. <http://www.jegs.com/i/jegs Performance Products/555/W41035/10002/ 1?parentProductId=3170 513>. 2. "Big Foot Stand." Kart Lift. Web. 21 Feb. 2016. <http://www.kartlift.com/store/index.php?route=product%2fproduct&path=11&product_id=57 > 3. "WinchLift HD." KartLift. Web. 21 Feb. 2016. <http://www.kartlift.com/store/index.php?route=product%2fproduct&path=10&product_id=52 >. 4. "Streeter Super Lift Black." Hepfner Racing Products. Web. 28 Feb. 2016. <http://www.hrpracing.com/streeter super lift black>. Appendices: Appendix A: Full Product Design Specification (PDS) Appendix B: Concept Drawings 12
Appendix A Figure 7 : Project design specification (PDS) 13
Appendix B Figure 8 : Forklift concept 14
Figure 9 : Scissor lift concept Figure 10 : Winch lift concept 15