Abstract[edit | edit source]
The spring 2016 Engineering 215 design class from Cal Poly Humboldt worked with with Zane Middle School (ZMS), located in Eureka, CA. The purpose of this association was to give an opportunity for students from the design class to experience working in teams, and also simulate how a project would operate in the job industry. Trevor Hammons is currently the main project liaison between ZMS and the Engineering 215 design class. Team J.A.T.O, (acronym consisting of the first names of the team members) has opted to create a project involving the use of vacuum.
Problem Statement and Background[edit | edit source]
The science department at Zane Middle School is in need of a demonstration that involves the use of a vacuum. Team J.A.T.O. decided upon creating a vacuum bazooka to demonstrate this. The goal is to build a Vacuum Bazooka that will propel a projectile utilizing suction force created by a vacuum. Ultimately our goal for the vacuum demonstration device is to provide an entertaining hands on demonstration that also provides an educational experience to the students and staff of Zane Middle School.
Implemented Project Criteria[edit | edit source]
During the construction of this project, we wanted to implement criteria or guidelines that reflected what we believe should be reflected in the project that we build. The following are a list of criteria that we thought would be the most important towards building our project.
Safety[edit | edit source]
Safety is important when taking this project into consideration. We decided that creating a vacuum bazooka would be a lot more interesting and fun to view for a crowd, as opposed to creating vacuum demonstrations that implement a bell jar or a farthing tube. When operating the vacuum bazooka it's important to be wary of your surroundings when firing projectiles. Make sure that no people or fragile objects are nearby the firing exit of the barrel.
Practicality[edit | edit source]
We wanted to develop a project that was easy to implement and use while fulfilling the desired objective assigned to us by Zane Middle School. While constructing our project we had this criterion in mind. We didn't want it to be too complicated for the students of Zane Middle School to operate. The vacuum bazooka is designed to be as simple as turning the vacuum switch on, erecting the vacuum bazooka in a safe firing position and putting the projectile in. A design that's easy to use and fulfills the objective effectively.
Sufficient Time[edit | edit source]
Following along the lines of "Practicality" as a criterion for this project, sufficient time was another criterion that we implemented for this project. The members of team J.A.T.O. are full time students so it's important that we developed a project that can carry out its objective, yet not consume a lot of time to build and be a potential project for someone else to replicate that won't take a lot of their time to build.
Material Availability[edit | edit source]
Having the available tools and materials is an important criterion for this project because we're dealing with implementing a vacuum. When constructing this project, it's important to have a hardware store nearby to get items such as PVC pipe, glue to seal any air patches between PVC connections, and a powerful vacuum cleaner to create a vacuum such as a shop vacuum.
Cost[edit | edit source]
We believed that if the project is going to practical, then it shouldn't be an expensive project. Total costs for this project equaling more than $200.00 is too expensive for this project. With $200.00 as our budget, we bought materials that would be able to be effective for our project yet fall within the budget.
Criteria Importance Rank[edit | edit source]
| Criteria List | Criteria Weight |
|---|---|
| Safety | 10 |
| Practicality | 9 |
| Sufficient Time | 8 |
| Material Availability | 7 |
| Cost | 6 |
Description of the Final Project[edit | edit source]
The final project is a fully operational vacuum bazooka. The vacuum bazooka is capable of shooting cylindrical projectiles that fill the volume of the PVC pipe. The cylindrical projectiles must fill the volume of the PVC pipe as this increases the suction force created from the vacuum, which in turn launches the projectile further. In order to make our vacuum we utilize a Shop-Vac 5986000 5-Gallon that has a peak of 4.5 HP. The shop vacuum is attached to a tee connector that is attached to the barrel. The length of our PVC pipe which composes our barrel is 5 ft. The Shop-Vac will be attached to a hose adapter which in turn will be connected to the tee connector. Once the Shop-Vac is turned on, a vacuum will be created by the Shop-Vac (from the pump within the Shop-Vac) which will create a suction force emanating from the tee connector. Once a cylindrical projectile is put in from the back of the vacuum bazooka, the suction force will propel the projectile towards the front of the vacuum bazooka and it will launch out.
Costs[edit | edit source]
| Image | Description | Quantity for Whole Project | Price per Quantity | Price for Whole Project | Place Purchased |
|---|---|---|---|---|---|
 |
PVC Pipe 1-1/2" | 5 ft. | $7.00 per 10ft. | $3.50 | Ace Hardware |
 |
Vacuum Pump | 1 | $70.68 | $70.68 | Amazon.com |
 |
Vacuum Accessories | 3 | Included with Vacuum Pump | $0.00 | Amazon.com |
 |
PVC Pipe Glue | 1 | $6.99 | $6.99 | Ace Hardware |
 |
Coupling PVC 3/4" x 1/2" SxS | 1 | $0.99 | $0.99 | Ace Hardware |
 |
CM Hose Adapter 2-1/2" x 1-1/4" | 1 | $7.99 | $7.99 | Ace Hardware |
 |
Nipple SCH80 PVC 3/4" x 3" | 1 | $1.99 | $1.99 | Ace Hardware |
 |
Tee San PVC Dwv | 1 | $1.99 | $1.99 | Ace Hardware |
 |
Red Spray Paint | 1 | $5.99 | $5.99 | Ace Hardware |
 |
Velcro Strip 4" Black | 1 | $3.99 | $3.99 | Ace Hardware |
 |
Electrical Tape | 1 | Donated | $0.00 | Omar Maciel |
| Total Cost | $106.10 | ||||
How to build[edit | edit source]
| Step | Description |
|---|---|
| 1 | Cut the PVC pipe so it is 5ft in length. |
| 2 | Apply PVC Glue Primer (purple can) to the inside of one end of the 'T' bracket. |
| 3 | After 1 minute of letting the Primer set, add the Glue (gold can) directly over the primer and twist the 'T' bracket onto the PVC pipe. |
| 4 | Clean off the excess glue and wait 15 minutes for glue to set. |
| 5 | Apply Glue Primer to the inside of the wide end of the CM Hose Adapter. |
| 6 | After 1 minute, add glue over the primer and twist the Hose Adapter onto the bottom of the 'T' bracket. |
| 7 | Take the Nipple SCH80 and cut one of the ends off when the threads stop (so half of it is smooth and the other half has threads still). |
| 8 | Apply Primer to the inside of the wide end of the Coupling PVC adapter. |
| 9 | Then apply Glue and insert the smooth end of the Nipple SCH80 (no threads) as far is will go in. |
| 10 | Apply Primer and Glue to the inside of the vacuum hose and insert the small end of the Coupling PVC adapter. |
| 11 | Finally, add Primer and generous amount of Glue to the threads on the end of the Nipple SCH80 (hold upside down so primer doesn't run down the components) and insert it in the black CM Hose Adapter. |
| 12 | Scrap off any dry Primer and let sit for 30 minutes for all pieces to dry. |
| 13 | Remove tip of the vacuum hose so that the bazooka is disconnected from the vacuum pump. |
| 14 | Sandpaper down the bazooka and spray paint your desired color/design (rough surfaces pertain paint better). |
| 15 | Let stand for several hours, then apply second coat if need be. |
| 16 | Take a strip of electrical tape and wrap around the back end of the PVC pipe so that half of the electrical tape is hanging off the bazooka. |
| 17 | Fold the excess electrical tape into the inside of the PVC pipe so it creates a slightly smaller opening in the back end. |
| 18 | Repeat step 16 and 17 to reinforce the integrity of the tape. |
| 19 | Wrap the outside of the front end of the bazooka (end of 'T' bracket) with a strip of Velcro so it is flush with the end. |
| 20 | Cut 2 pieces of thick fabric (i.e. a belt), one so it covers half of the opening and the other so it could cover the entire opening. |
| 21 | Now attach the other side of the Velcro to the ends of the both pieces of fabric so they can be attached and removed from the front end of the bazooka. |
| 22 | When the 2 pieces of Velcro are placed across from each other on the end, the vacuum will close them like a flap. |
| 23 | Test the vacuum to make sure all the components are sealed vacuum tight and that the cap is will open and close on it's own. More Velcro may be needed if the projectile knocks off the flap. |
Testing Results[edit | edit source]
After several design, projectile, and vacuum changes, we were able to have a sequence of consecutive runs. At just above a 45 degree angle, the projectile launches a distance of around 6 meters. One problem we were facing had to do with the repeating cap and how many consecutive launches could fire before it fell off. We decided to implement a different way to cover the cap so that it doesn't fall off after being fired. It is also important to keep in mind that the bazooka isn't fully completed and improvements may be made before the unveiling of the final design.
Video of the Vacuum Bazooka[edit | edit source]
Team J.A.T.O.[edit | edit source]
References[edit | edit source]
Information used to help construct the project:
"Atmospheric Pressure." (2015). Atmospheric Pressure, Georgia State University, <http://hyperphysics.phy-astr.gsu.edu/hbase/pman.html> (Feb. 24, 2016).
Berto, F. J. (2015). "Hydrostatic Tank Gauges Accurately Measure Mass, Volume, and Level." Oil and Gas Journal, Oil and Gas Journal, <http://www.ogj.com/articles/print/volume-88/issue-20/in-this-issue/refining/hydrostatic-tank-gauges-accurately-measure-mass-volume-and-level.html> (Feb. 25, 2016).
"Brian Cox performs Galileo's Experiment in Vacuum." (2015). Brian Cox performs Galileo's Experiment in Vacuum, <http://web.archive.org/web/20150402011537/http://thesciencegeek.com/?q=node/78> (Feb. 25, 2016).
"Dropping Object's in the World's Largest Vacuum Chamber." (12ADAD). Wired, <http://www.wired.com/2014/11/dropping-objects-worlds-largest-vacuum-chamber/> (Feb. 25, 2016).
Engelmann, G., Genet, M., and Wahl, W. (1987). "Vacuum Chambers in Composite Material." Journal of Vacuum Science and Technology A, 5. (Scholarly Journal)
Gura, J. (2011). "Fischer Technical Company.": Top 5 Experiments Using a High Vacuum Pump, Fisher Technical, <http://fischertechnical.blogspot.com/2011/05/top-5-experiments-using-high-vacuum.html> (Feb. 25, 2016).
Herring, D. (2015). "High and Ultra-High Vacuum." Vac Aero, Vac Aero International INC., <http://vacaero.com/information-resources/the-heat-treat-doctor/1167-high-and-ultra-high-vacuum.html> (Feb. 25, 2016).
"Introduction to Vacuum Gauges." (2015). <https://www3.nd.edu/~nsl/lectures/urls/introduction_to_vacuum_gauges.pdf> (Feb. 25, 2016).
"Mean Free Path." (2015). Mean Free Path, Georgia State University, <http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/menfre.html> (Feb. 24, 2016).
"Physical Equilibria." (2015). <http://ch302.cm.utexas.edu:80/physEQ/physical/physical-all.php> (Feb. 25, 2016).
"Q & A: Creating a Vacuum." (2015). Q & A: Creating a Vacuum, University of Illinois, <https://van.physics.illinois.edu/qa/listing.php?id=896> (Feb. 25, 2016)
Umrath, walter. (2007). Fundamentals of Vacuum Technology. (Book Source)
Weissler, G. L., and Carlson, R. W. (1979). Vacuum physics and technology. Academic Press, New York.
(Scholarly Journal)