San Francisco, California
London, United Kingdom
RooBuilders is on hiatus this year but we are planning on having a Metro Builders (free – yes you read that right FREE) competition this spring entirely based upon bridge efficiency. It will be hosted in the Northland by Park Hill South STEM club along with Tom Greer from MSPE and Dr. Megan Hart ( firstname.lastname@example.org for questions), adjudicating. Materials will be shipped to registered teams. No video, no aesthetics, no highest load, just bridge efficiency so the highest load divided by the weight of the bridge as in the International Bridge Competition. Registration/check in will begin at 9 am on Feb. 4th. The competition will begin at 10 am and go to approx. 2 pm. Please see the rules below.
To complete your registration, please fill out this survey. It will ask for your school, number of team members, t-shirt sizes, and a mailing address that we can mail materials to. If you can't access this survey, please contact Dr. Hart. This survey must be completed by Dec. 31st for you to register, although it does not need to be submitted at the same time as your registration.
While the event is hosted at Park Hill South, we are rooting for all of you to win! We hope to bring back RooBuilders next year but until then, this should fill your bridge building needs! Please feel free to forward this message and get the word out as needed! If you need help modeling or would like to request a modeling session, please state that in your registration along with your address so I can mail your construstrion materials ASAP.
UMKC will provide the bridge construction materials which consist of 36 balsa wood sticks (1/8 inch x 1/8 inch x 36 inches in size), glue, and a cardsheet. Only the materials provided may be used for the construction of the bridge.
The design dimension sof the bridge are illustrated inFigure1(a) and shall be as follows:
Materials and Construction
- The bridge span (support-to-support) will be 28 inches.
- The total bridge length may not exceed 36 inches.
- The bridge height shall be between 5 and 10 inches.
- The bridge width shall be between 3 and 6 inches.
- Completed bridges may not weigh more than 40 grams (about 1.5 ounces) above the weight of the 36 sticks of balsa wood provided to each team.
- The bridge may not be painted, coated, treated, or decorated. Reinforcing the balsa pieces with glue is not allowed.
- Bridge members (balsa wood sticks) should be individual and shall not be laminated or bundled together. Bridge members (balsa wood sticks) may be overlapped with a maximum of ½ inch overlapping length as show in Figure 2.
- Bridge members may be joined together at their ends by gluing gusset plates over the joints using the provided card sheet. Gusset plates may be of any shape; however, the maximum dimension of the gusset plates shall not exceed ¾ inch, as shown in Figure 3.
- No supports below the bearing plates are allowed. The bearing plates will be placed on the lowest members of the bridge. (NO UNDER TRUSSES!!).
- The bridge will be load tested during the competition to failure. Two 2 in. x 2 in. x 0.5 in. metal plates with loading rod will be placed on the road deck of the bridge, centered at 10 inches from each of the support bearing seats. The loading rods hang below the lowest chord of the bridge. To enable the bridge to be load tested, the bridge must be constructed to accept the metal plates and loading rods at the locations shown in Figure 1(b).
- Each bridge will be evaluated by the judges prior to testing for compliance with the construction specifications. Bridges that fail to meet the construction specifications may be disqualified or suffer signficant point deductions. Bridges disqualified prior to the start of the competition may be tested as exhibition bridges at the discretion of the team and competition directors.
- Each team’s constructed bridge will be weighed prior to the load-testing phase of the competition. The final weight will be used in the efficiency calculations of the bridge.
- Each team will be given five minutes to prepare their bridge for evaluation. Preparation includes placing the bridge on the support bearing seats and installing the metal plates with loading rods on the bridge.
- The two support bearing seats will be placed on a flat, level surface 28 inches apart. The facing planes of the support bearing seats will be parallel and exactly 28 inches apart. The bridge will be placed on the support bearing seats.
- The bridge may only rest on the support bearing seats. The bridge may not bear on the inner sides of the support bearing seats and no additional support from the floor, ceiling, walls or any other object is allowed.
- The bottom chord of the bridge, as shown in Figure 1, shall not be lower than the top of the support bearing seats.
- The bridge will be subjected to two-point loads at 10 inches from each support. The loads will be applied at the bottom chord of the bridge.
- The bridges will be load-tested to the point of failure. Each team has a maximum of 5 minutes to completely load their bridge to failure.
- Failure of the bridge is determined as: Complete collapse of the bridge (Defined as when the bridge is no longer able to carry any additional loads) or Excessive deflection (sagging) where the bridge is no longer able to bear load or otherwise no longer functional
Awards will be given for first, second and third place teams in each division. Additionally, a Judge’s Choice award will be given at the discretion of the Mr Greer and Dr. Hart for each division. The 1st place winner of the high school competition team may receive a scholarship for those choosing to attend UMKC and plan to major in engineering or computer science.The winners will be determined based on the total efficiency calculated as (maximum load)/(weight of bridge). All Judges’ decisions are final.
When & Where
Dr. Megan Hart, UMKC
RooBuilders is a annual balsa bridge building competition put on by Dr. Hart at the University of Missouri Kansas City but it is on hiatus for 2016. For more information consult the webpage here: http://sce.umkc.edu/hartme/roobuilders/