Background of the HPVC challenge:

Designed to provide an opportunity for students to gain valuable design team experience, the Human Powered Vehicle Challenge (HPVC) is a yearly competition put on by the ASME, or American Society of Mechanical Engineers. The HPVC sets the stage for students to demonstrate engineering design skills in the development of sustainable and practical transportation alternatives. As an all volunteer project with no school credits that will be awarded, members of these HPVC teams are all extremely dedicated and knowledge-thirsty students.

Design/Build:

Since the car will be powered entirely by the human driver, the Human Powered Vehicle is going to need to be quite aerodynamic – especially if it is going to be entered into competition drag races against over 30 different college teams. A key part of the design process is constructing the fairings, of which the master molds were made out of donated Precision Board Plus PBLT-10.

This was the first time University of Missouri students had used Precision Board Plus to construct the fairing molds. Last year they used insulation foam, fiberglass, and bondo, which has a high room for error, especially for newer students. According to Jonathan: “the high level of accuracy and time saved by using Precision Board Plus was a huge improvement over previous techniques, and the team cannot wait to use it again next year”. Jonathan was even kind enough to detail this years mold making process for constructing the fairings for me:

1. Acquire the basic criteria for the vehicle based on the released rules

2. Design and test a prototype frame and make necessary changes

3. Fabricate the prototype frame

4. Acquire rider data by taking rider body part measurements and determining range of motions of each rider by taking motion capture photos of each rider on the bike with high interest points marked by high output LED’s.

5. Construct a computer rider model using the rider data.

6. Using the model, construct a basic vehicle fairing (take into account thickness, mounts, clearances, etc.)

7. Run iterations of CFD by changing certain aspects of the fairing until the final fairingis completed.

8. Using the final model of the fairing, design models of the molds and create blocks of Precision Board Plus that correspond to the computer models.

9. Using the computer files, 5 axis CNC the molds

10. Remove any remaining machining marks in the foam, apply a surface hardener to the molds, and then finish the surface of the molds.

11. Lay-up the fairing in the molds using a wet layup and vacuum bag method and seam the fairing together accordingly once the parts have fully cured.

12. Mount the fairing to the frame and check clearances.

13. Remove the fairing, make paint preparations as necessary, and then paint.

14. Re-mount the fairing.

One of the key lessons Jonathan learned from his involvement with the Human Powered Vehicle Team is that many ideas are limited only by manufacturing capability. For example, last year students had a great idea of building a hollow crank to save on overall weight. However, a veteran team member pointed out that they were using 7075 T6 Aluminum, which is a non-weldable metal. Not wanting to give up, they began researching possible methods to remedy this.

What they found was a form of welding known as Friction Stir Welding, which uses lots of heat and friction to join metal without actually melting it or changing the properties, and is also the highest-strength welding technique available. As luck would have it, a different department at the University was doing work using Friction Stir Welding, and had the equipment needed. Unfortunately, after the initial crank was built, it was discovered during testing that it was slightly deformed beneath the weld, rendering it unusable. However, they were able to carry the experience gained over to this years build, where they successfully used a hollow crank made from Titanium and stir-welded.

In the car experience:

When asked about his experience as one of the drivers, Jon mentioned that “inside the car it is a very tight fit, but it is quite enjoyable to drive.” Top speed on a sprint run is about 45 MPH, and with a skilled driver and long straightaway, these vehicles could go as fast as 60MPH! All of the drivers are secured with a 4-point racing seatbelt, and each car is designed to withstand hundreds of lbs. of concussion force in the event of a crash.

Competitions:

Each year the HPVC has 2 different events: East and West competitions, which consist of several races at each event. The races are determine by finishing position, and the overall award is determined by total points from all of the races and the design competition. There are several different scoring events:

1.  Design – 40% of total score. They placed 4th in the East Coast competition and 5th in the West Coast competition.

2. Female Drag Races – 15% of total score. Suffered a mechanical failure at the East Coast competition and still finished 2nd place. Took 1st place at the West Coast competition.

3. Male Drag Races – 15% of total score. Placed 1st at both the East and West Competitions.

4. Endurance Race – 30% of total score. 2.5 hour endurance race with 4 drivers for each vehicle. Finished 1st at to both East and West competitions.

Won the overall award for the West Coast competition and took second place to Rose-Hulman Institute of Technology by a single point.

In an interesting and rare turn of events, the University of Missouri and Cal Poly actually ended up tying in points at the West Coast Competition for the overall award. The University of Missouri ended up breaking the tie by winning all of the races. Congratulations to the University of Missouri for a job well done!

An excellent video of the HPV can be seen at: http://vimeo.com/41952419

Pictures from the fairing build process:

]]> http://www.precisionboard.com/blog/human-powered-vehicle/feed/ 0 http://www.precisionboard.com/blog/terps-racing-part-2/ http://www.precisionboard.com/blog/terps-racing-part-2/#comments Wed, 09 May 2012 14:55:02 +0000 burnett http://www.precisionboard.com/?p=4461 The University of Maryland Terps Racing team recently unveiled their brand-new 2012 Formula SAE car. They are looking forward to an upcoming first race, which will be held in Ontario, Canada on May 24th, and is known as Formula North. Over 70 school teams out of 1200 worldwide will be competing, and University of Maryland currently ranks 10th out of all 1200 schools. All of the individual school rankings can be seen here. They will be competing in two major races for Formula SAE, and will also participate in an additional 8 races for the SCCA, or Sports Car Club of America.

Engine:

I had the opportunity to speak with C.J. Gorrell, student at U of MD and also Project Manager for the 2012 Terp’s Racing program, about some details of the new car. This year, Terps will be using a single cylinder 450cc Honda Dirtbike engine. This engine, coupled with the aerodynamic bodywork, will enable the car to accelerate from 0-60 in less than 3 seconds. They are also expecting it to pull 3-4 lateral g’s on the corners. Last year, the 2011 car used a Honda FY 600cc street motorcycle engine, and while it did have slightly more horsepower (60hp as opposed to this years 45hp), the lighter weight and improved design of the current car will enable faster lap times. They are also planning on turbocharging the car later in the season, which will bring the horsepower to 60+. A penalty is issued for using too much fuel, so keeping the displacement, and weight down are key to top results.

Design:

Aside from an improved engine configuration, lap times this year will also be decreased due to a major redesign of the car’s under tray. As referenced in our previous blog post: Terps Racing – 2012 Racecar Design, our donation of high-density Precision Board Plus was used to make a 3d model of the under tray. This will add 150lbs. of additional downforce to the car and improve aerodynamics. In the past, students have used MDF to create master patterns, which took over 10 weeks for machining to be completed, as opposed to the 1-2 weeks Precision Board Plus took. They also praised the higher level of accuracy attained by using HDU.

Track:

Each race takes place on an auto-cross style track, and each team is ranked by time trials.  The track is quite narrow at 12ft. wide, and has many varying curves designed to challenge each driver. The University of Maryland will field 4 different race drivers, who were selected based on lap times from earlier tests. Speeds will reach over 60mph for the faster cars.

Check out the Terps Racing Facebook for many more pictures and regular updates on the car!

Also see the Official Terps Racing Website: http://www.terpsracing.com/

Here is a great video of the 2011 Terps Racing Car in action:

It will be constructed out of composite materials, and features a tumblehome wave piercing hull. Water sleeting along the sides, in addition to passive cool air induction in the mack, lead to reduced thermal emissions.

Many of you probably remember the WW2-era destroyers and battleships that employed dozens of large-caliber cannons to provide naval fire support, and have probably noticed the absence of such large cannons on today’s ships in place of guided rockets. The Zumwalt class of destroyers has a planned naval surface fire support role and will have two 155mm guns. They will fire guided artillery shells that can travel 63 nautical miles inland. It will also be built to house the new electromagnetic railgun that is being developed by the navy.

An interesting article on the Zumwalt can be found here.

This competition is designed to help mechanical engineering students fast track towards an entry-level position in the automotive design field by promoting hands on skills in all aspects of design, testing, marketing, management and financing.

Each competition has over 70 schools, and worldwide there are over 1200 different teams. Coastal Enterprises regularly donates Precision Board Plus to many schools involved in the SAE competition. If you happen to be near College Park, MD, you can attend the unveiling of the 2012 Terps Race Car for free at the Jeong H. Kim Engineering Building Plaza. The Terps Racing project manager, C.J. Gorell, will be sending over pictures and details of the build process after the unveiling, so be sure to check back soon to see how Precision Board Plus HDU is involved in this innovative process!

The mission is designed as a comprehensive evaluation as one of the final steps before SpaceX becomes the first commercial carrier delivering payloads to the ISS. The goal is to demonstrate SpaceX’s capability to launch, rendezvous with the ISS and return to earth.

Mission time is roughly 4 days, and Dragon will dock at the space station for 18 days, offloading 521 kilograms of cargo and loading 660 kilograms from the station for return to earth. SpaceX also has 2 additional launches planned for later this year.

Check out the original article, SpaceX Given Green Light For First Launch To Space Station, courtesy of Wired.com.

Vacuum forming is a variation of thermoforming, where a sheet of plastic is heated to a certain temperature, and then stretched onto a mold. It is held against the mold by applying vacuum between the mold surface and the sheet. Dashboard, product packaging and many other products are commonly made using this technique.

Precision Board Plus HDU is used to make vacuum-form tools because it is a lower cost alternative to wood and metal and can be machined much quicker.

This is a picture of a vacuum form tool:

PB Hardcoat is a rock-hard protective coating that can be used to simulate wood grain, stucco, stone and other textures – all without needing to prime the substrate.

Check out our step-by-step PB Hardcoat video here:

TSF-45 is a tough, flexible coating that can be finished using the same methods for finishing cementitious-type plaster products. It can be swirl textured, skip troweled, stucco finished, stipple finished, or used to simulate wood grain. No primer coat is needed, and paint can be applied directly to it.

Check out the step-by-step TSF-45 video here:

Call us at: (800) 845-0745 or email us at: hdu@precisionboard.com for your free sample.

Ideal for composite layup tooling, prototyping, foundry patterns, vacuum form molds and autoclave tools, PBLT-70 offers increased durability and compressive strength for many applications.

Temperature:

PBLT: 200˚F

Sheet sizes:

20″x60″, 24″x60″, 45″x60″, 30″x80″, 45″x60″, 4′x8′, 4′x10′, 5′x8′, and 5′x10′

Thickness:

Anything from 1/4″ to 24″ thick

Need a custom size block? Check out this blog entry about how our custom size blocks decrease machining time.

Interested in seeing a sample of PBLT-70 or PBHT-70? Call us at: (800) 845-0745 or email us at: hdu@precisionboard.com

Here are some pictures from the booth setup today. We will be posting pictures of show highlights once ISA kick’s off in our next blog!