This report is prepared by mechanical engineering students from British Columbia Institution of Technology for 2018 ASHRAE Student Design Competition. The goal of this project is to design heating, ventilation, and air conditioning (HVAC) system for a 70,000 ft2, four story mixed use building in north of Istanbul, Turkey. The building contains retail spaces, a restaurant, office spaces, as well as hotel area. The design of the system is based on owner’s project requirement (OPR), complied with latest ASHRAE Standards 55, 62.1, 90.1, 189.1, and ASHRAE Handbooks with consideration of Turkey Building Codes. The HVAC design includes zoning, ventilation rate and load calculations, system selection, energy analysis and life cycle cost analysis over 50 year’s life of the facility.
This report is submitted by a team from British Columbia Institute of Technology for 2018 ASHRAE student design competition (Design Calculations). The objective of the competition is to perform the design calculations to correctly size the variable air volume HVAC system for a four-story, 70,000 ft2 mixed used complex north of Istanbul, Turkey near Arnavutkoy. The facility features retail, office spaces, a restaurant, and a hotel.
This report covers the research and testing of the rumbling phenomenon found in the drivetrains of high-pivot rear suspension mountain bikes, specifically those made by Norco
Bicycles. This includes the project definition and objectives, a theoretical background of the problem, the development and testing of an analytical model, the design and
development of a physical test bench, discussion of test results, the applicable findings, and the final conclusion.
The problem being addressed in this project is the drivetrain rumbling found in high-pivot mountain bikes. High-pivot mountain bikes allow for less momentum losses when rolling
over square-edge bumps than a low-pivot bike, though an idler sprocket needs to be added near the pivot point to address the excessive chain growth. This idler is thought to be the cause of this rumbling; it is the objective of this project to research this phenomenon and try to discover a drivetrain design that minimizes the effect.
It was hypothesized that the polygonal nature of the idler, through the pitch polygonal effect, is the main cause for the rumbling. Due to the idler being a polygon, the radius
varies as the chain engages and disengages with the sprocket, thus causing slight changes in the gear ratio. These changes can be felt by the rider as a rumbling. By changing the tooth count and position, therefore the wrap angle of the idler, the changes in gear ratio at both ends can be brought either into phase or out of phase by 180°. The project team hypothesized that the ideal setup would be at one of these two extreme cases.
To discover the optimal design, the testing was broken up into two groups: first, simulations were run through an analytical model, and second, the theoretical results were
validated through testing on a physical test bench.
MATLAB was used to create the analytical model. The model was a 2-dimensional representation of the chainring, idler, and cassette, each made up of discrete points.
Different parameters such as tooth count, and relative position could be specified. It was chosen that the simulations would be performed at 25% bike sag, the position riders would be pedaling. The final output of the simulations was maximum change in gear ratio for a specific tooth count, as well as optimal relative position for the idler for a specific tooth count. It was found that the best case, given a number of assumptions, was using a 14-tooth sprocket, and the worst case was using an 11-tooth socket. It was decided that these to tooth counts, as well as the Norco standard 16-tooth and second best 18-tooth would be experimentally tested.
To allow for data validation, a test bench was designed and manufactured. It was designed to transmit a constant force from a hanging weight through the drivetrain to a scale on the other end, where the tension could be read. The relative positions of both the cassette and the idler could be adjusted, to allow for various sag positions and wrap angles. Through additional pulleys at the weight and the scale, the reduction would be amplified to allow the scale to read the changes in chain tension. The pulley sizes were chosen by calculating the change in chain tension for a set weight and comparing that to the scale’s resolution.
To discover an optimal solution, various variables were tested. These include idler tooth count, idler position, sprocket material, tooth profile, and the chain-line. Five individual
tests were run for each to allow for more consistent results. The results of each were compared to see how they influence the drivetrain performance.
After testing was completed, that both the tooth count and the idler position had the greatest effect on the change in gear ratio. For tooth count, a 14-tooth idler resulted in
significant reductions in gear ratio change compared to an 11-tooth idler, almost a 94% reduction. By moving a 16-tooth idler to its theoretically optimal position, reductions in
gear ratio change of 38% were observed. However, it was found that both the tooth profile of the idler, as well as is material made little difference.
Through this, it was found that a possible optimal bike frame design could exist, and through more thorough research using the above methods, drivetrain rumbling could be reduced to negligible levels during the design of a high pivot mountain bike.
The project was completed as of May 5, 2019. The project will be showcased at the BCIT Engineering Expo on May 10, 2019.
While on a ship of any size, it is desirable to have a stable deck to ensure maximum safety and enjoyment for passengers. Ships have normally relied upon the design of their hulls for stability. However, even with a superior hull design, ships are incapable of completely mitigating such rolling motion. To reduce rolling motion further, an additional stabilization system must be implemented. This report documents the development of such a stabilization system in response to the request for proposal (RFP) received from WaterWorks Co. on October 17, 2017.
With the rapidly growing cannabis industry – especially in cannabis farms, innovation has been geared towards automation and process efficiency. Automation can be best applied once data is analyzed. One critical data in the greenhouses is the product volume flow rate. This report provides an overview of the problem statement based on the RFP released by Keirton, a description of the design approach and implementation, and a discussion of the results obtained. The project involves the design and prototype of a volume flow rate measurement control system that allows manual or automatic motor speed control. The volume flow rate measurement device is achieved using a custom designed level measurement device in conjunction with a PLC. A MSP430 microcontroller is used as part of the sensor to output a cross-sectional area measurement to the PLC where it is used with speed data from the VFD to calculate the volume flow rate. An HMI (human-machine interface) displays the current volume flow rate through the sensor and allows the user to choose one of two available modes. Automatic mode requires a user input volume flow rate setpoint and adjusts the motor speed accordingly to achieve the setpoint. Manual mode only displays the volume flow rate reading and allows users to control conveyor speed directly. The project cost came to $4,500, and termination date was May 10, 2019.
Servo motors are complex electro mechanical units that allow their rotational position, velocity, acceleration, and many other aspects to be controlled very accurately. Specialized control modules and programming is required for these motors to exhibit desired behavior. Both factors vary drastically between competing companies such as Bosch Rexroth and Allen Bradly.
These motors and drives are used extensively in industrial settings, which are very costly and hazardous settings to learn their functionality. For this reason, Bosch Rexroth develops servo trainers that replicate industrial processes at a desk sized scale to render learning safer and cheaper. This project resulted in the design and manufacturing of a trainer system, which consists of two portable units: The electrical controls (Alpha Prototype), and the emulation of an industrial flying saw (Beta Prototype).
Handcycling is a popular hobby carried out by many individuals. A few of these individuals are however in a wheelchair and transporting their personal hand-cycle can lead to astray of difficulties. Most of these difficulties involve the user in the wheelchair having no assistance to mount the hand-cycle to the car in an efficient, safe and effective way. This is where the introduction of a handcycle car rack takes place.
There are a variety of handcycle car racks on the market today however the reliability, durability and ease of use is always in question when it comes to the car racks currently used. The price of some of these is astronomical and just not affordable for the majority of wheelchair users. Also, with the use of electrical components raises the issue of reliability of the rack especially in the harsh climates that occur in the Vancouver area.
Throughout this project, the team and the client have been closely working together to come up with a handcycle car rack that can be easily used by the client while using no electrical components.
In response to request for proposal (RFP) document by Buzz Drone Inc., the design team at Falcon drone Inc. was contracted to design and develop a hybrid drone as a proof-of-concept. The objective of the project was to build a fully functional prototype of a drone that had the ability to both fly and drive on land. By adding the driving feature, the goal was to save energy and reduce power consumption due to the limited power supply that a drone would typically have from just its battery. This project was divided into two phases: Phase 1 which focused on the drone portion of the project, and Phase 2 which incorporate the addition of the driving aspect to the drone. The design was targeted towards the hobbyist drone market, including consumers, enthusiast, educators and new users. They require the drone to be unique, enjoyable to use, lightweight, portable, compact, robust, easy to user, safe and reliable. Moreover, some technical requirements include a maximum weight of 3.5 kg and maximum size of 2.5 ft3.
The deliverables of this project include a 3D model, fabrication drawings and stress analysis of the final concept using SolidWorks, a wiring diagram, a LabVIEW code for the drone and drive controls and a physical prototype.
In terms of documentation, a proposal presentation, a design review package and presentation, and a final report and presentations were required as well.
The scope of the project consists of current status research, concept generation, concept selection, design refinement, theoretical background research, and prototyping and testing.
The current status research included research on drones that were currently in the market and patented. Through this, concepts were generated through sketches, then selected and further refined to ensure requirements were met. Significant changes to the design were made throughout this process. The chosen concept was modelled in SolidWorks, where a brief stress analysis was conducted for verification.
Further research was conducted regarding the design and operation of drones, which included aspects about the sizing of their propellers, motors, electronic speed controllers (ESC) and battery. Research was also conducted regarding the drive mode motors. Control of the motors for both the drone and driving aspects were investigated as well. This included rolling, pitching and yawing in drones and various speed differentials that would allow the drone to maneuver on land.
The design incorporated both off-the-shelf components and customized parts. The entire manufacturing and assembly process was documented. This involved various process such as hand lay-up for the composite baseplates, drilling, band sawing, milling, punching and sanding. As well, a wiring diagram was provided to illustrate the connection between the electrical components. Lastly, details regarding the LabVIEW program was explained in detail to demonstrate how the drone was controlled.
Multiple tests were conducted in order to refine the controls, which incorporated a complementary filter, low-pass filter, average calculator and PID control. Despite facing various mechanical, electrical and programming challenges, Falcon Drone Inc. was able to successfully build a physical prototype for Buzz Drone Inc. by May 3rd, 2019 which met the technical requirements and needs of the customer.
The surf foil system detailed herein was designed at the request of Poseidon Adventures Ltd. Included in this publication are links to the part models and STL files for all of the components that were designed for the surf foil system.
The component parts that were designed for prototyping are both wings, the mast, and the fuselage of the surf foil. The front wing has a span of 32", the rear wing has a span of 16" and they are roughly 1" thick. The fuselage is 30" long and is made from 1" dia. aluminum rod. The manufacture of the fuselage and both wings were completed. A mast was purchased for the assembly of the product for final presentation due to time restrictions. The design of the mast is complete, its manufacture is ongoing at the date of this report's publication. The overall weight of the surf foil system including the purchased mast, mast pedestal, and board mount is 8 lbs.
An emphasis was placed on using standard dimensions whenever possible so that commercially available parts could be used as a replacement for an individual component in the event of a catastrophic failure.
Reproduction of the surf foil is possible but be mindful of careless operation of this device. This sport is dangerous, so use it at your own peril. Head protection and life vests are always recommended, as well as protection of the eyes.
The project commissioned by DOS Watersports requires a development of a functional prototype of an indoor paddle board trainer. Some of the requirements for the paddle board trainer included inertia and variable resistance. The scope of the project was focused solely on the paddle motion and not the user’s ability to balance on the paddle board. The form of resistance was open ended, as well as the budget for the paddle board trainer.
This project’s objective is to analyze the physical concepts behind hydrofoils using the principles of aircraft design and aerodynamic wing theory. The team investigated the design concepts that go into the airfoils for planes and selected a suitable NACA airfoil to use in our project. We also researched the design decisions that go into the designs of the front and back wings; as well as, the fuselage. The team familiarized themselves with the technical nomenclature of the airplane industry and applied the mechanics in their design. Experts in carbon fibre architecture and avid surfers were consulted for their input in the design.
The team decided on a design with a dihedral angle for increased roll stability and a foil wing with a high aspect ratio. The NACA profile we chose was a very cambered profile, the NACA 6412. This allowed us the highest lift coefficient for the lowest attack angle.
The next section discusses the evolution of the design from the concept to the final manufacturing prototype. It contains the steps to manufacture the prototype from gluing the MDF board, CNC cutting the core, carbon fibre layup to the final surface finishing.
Finally, this report discusses the problems encounter during the manufacturing of the foil. It documents the errors we encountered like tool bit collision, collet collision, following error, tab thickness and epoxy surface layer. We conclude this report with the future work and improvements we could do with the manufacturing of the hydrofoil.
The following report outlines the detailed design process followed by the construction of a 3D printer prototype was conducted throughout this project. The purpose of the project was to create a 3D printer with tool changing capabilities, a high degree of resolution, and a print volume of 300x300x300mm. The final product was handed over to Stephen McMillan, at which point it was added to BCIT’s fleet of rapid prototyping technologies.
The design process followed that of typical iterative engineering design methodology. Initially, the process began with rough hand sketches and conceptual design reviews, followed by solid modelling in SolidWorks, and finally the construction of a physical prototype.
Initial difficulties included finding the optimal placement of the critical components throughout the frame such as the electronics and the X, Y, and Z motion control systems. Deciding on the placement and orientation of each of the major components required the use of much foresight into the latter stages of project progression. Throughout the manufacturing process, it was found that many of the design choices required an immense amount of time in the shop due to lack of experience and high tolerances – this further extended the project length due to the vast number of custom parts created. Testing and calibration procedures had to be performed in a systematic manner due to the inherent dependency of systems between one another, requiring an extensive trial and error process to achieve the desired results. A project scope change was required to be made after the final design was agreed upon due to the tool changing components not being made commercially available, and were instead stuck in beta testing phases. The shift from this major scope change required a high degree of adaptability in order to work around the road block while still providing the proof of concept and infrastructure required to meet the initial goal.
Throughout the manufacturing process, the design of the model also changed, allowing for a significant decrease in the total time required for construction, making predominantly minor adjustments where needed. Once the manufacturing was complete, tolerance stack-up was considered and remedied through the extensive foresight of adjustable mounting options. The resulting motion control systems were executed as originally planned, with a rising and lowering Z-axis and a planar CoreXY motion system positioned at the top of the printer. Further results included the successful integration of the electronics with the aforementioned motion systems –providing the adequate power, safety, and maintenance requirements.
Through the employment of an extensive design process backed up by key resources and expertise, the revised project goals set forth during the project were successfully completed. The total cost of the project was just over $2,300 CAD, a fraction of comparable products available on the market.