Engineering Projects/HoverCraft/Howard Community College/Fall2011/501 Glorious2

Problem Statement
There are many working models of Hovercrafts, some large and some small. However, the large ones are often piloted by a person, and the smaller ones are controlled with a remote controller. To the best of our knowledge, there are not many models that utilize an autopilot system and sensors that can avoid people yet travel down a crowded school corridor.

Team Members

 * James Morgan
 * Parlette
 * Blomme

Summary
Since we already had the base of the hovercraft and the downward fans glued down, we were able to start the project off by trying to figure out how to get a good amount of power going to the two fans. Our first attempt, we attached two 9 volt batteries together to power the two fans in parallel. We had wires from the batteries going through a switch, so that we could just easily turn the fans on and off. The fans were blowing a decent amount of air, but we did not have enough current going to them. So, later we get this 11.1 volt rechargeable battery, and it had a lot more current going through the circuit to power the fans. It was pretty much perfect. But, the plastic wrap around the Styrofoam was not a good enough skirt. We needed something that had less surface area to reduce the friction. We ended up making a skirt out of duct tape, and it only goes around the outside of the bottom of the hovercraft. In addition to that, we needed some way to push the hover craft forward. We had tried the fans that were available in class, but none of them were good enough. Instead, we decided to try just using a motor with a propeller attached to the end. We have no yet gotten to test it to see if it will work, but that is the next step.

Put an overall, one paragraph summary here with links to the team weekly reports.

Poster






http://www.youtube.com/watch?v=qPR6dG7slQw - Our hovercraft using the two 9 volt batteries with approximately 400 milliamp-hours

http://www.youtube.com/watch?v=gCx19otHe7g - Our Hovercraft using the one 11.1 volt battery with approximately 2100 mAh

Story
The first week of the project was spent on getting the hover craft to move, and to do so smoothly. The problems encountered were having air pushing downward, but the craft not moving smoothly. The thought then was that if weight was evenly added, it would build up the pressure of the air beneath the craft, and provide a smoother movement.

The next week was spent more individually than previous weeks. One job that needed to be worked on was adjusting the hovercraft so that it would slide across the floor more fluidly. The other task was to find alternate power sources and fans in case the ones we were using at that time were not powerful enough. The adjustment task was tackled by attempting to build a better skirt design around the craft rather than using the plastic wrap that the styrofoam block came in. This new design was made out of duct tape and started taking on the shape of a tube structure around the edges. However, it soon became clear that this design was unbalanced and not as efficient as we had hoped. A new design was built, this time just a flat cushion shape around the edges rather than a tube. This turned out to be much more efficient, and the hovercraft slid more smoothly. The other task was gone about by searching stores and online websites for stronger batteries and larger fans. The places searched included Amazon and Radio Shack, to name a few. Several batteries were found, but were waited upon until it was determined whether or not the new skirt design would work well enough to warrant not ordering the new batteries.

The last two weeks on this project were spent trying to get the fans on the back working efficiently. This often proved difficult. The battery we changed to was certainly more powerful, and provided much more lift, and arguably the smoothest movement of the hovercraft so far, and yet, it was dangerous. The battery could explode if overcharged, and when the two connectors were accidentally touched together, a large amount of sparks was produced. This led us to believe that we needed to get a new battery, one that was less dangerous, yet still powerful, or go back to the power source we had used in the beginning to test whether or not the fans actually worked. At the end of four weeks, we have taken the almost finished body we had at the end of project one and have spent our time modifying it and tweaking the design to produce an efficient hover craft. Work still needs to be done to provide thrust and a quality power source needs to be found, but good progress has been made.

Decision List
1. We decided to power the two bottom fans in parallel with two 9 volt batteries that were connected in series.

2. We decided to make a better skirt on our hovercraft, out of duck tape.

3. The skirt was not tight enough and it was not uniform all the way around, so we re-made it tighter and neater with duck tape again.

4. We decided to use an 11.1 volt rechargeable battery to power the two bottom fans instead of the two 9-volt batteries.

5. We decided to give up on using the fans that were available to us in the classroom to propel our hovercraft forward. Instead, we decided to try to use a motor with a propeller attached to the end of it to propel the hovercraft forward.

6. We decided to use a generator to power our motors on the back of the hovercraft until we can determine exactly how much voltage and current we will need and then we will find a battery after we have it all working, because it was too difficult to find a good battery to use and it was taking too much time.

Material List
-rectangle of Styrofoam for our base

-the plastic that came wrapped around the piece of Styrofoam.

-2 fans to blow downward

-2 motors with 2 propellers to propel the hovercraft forward.

-epoxy glue to glue down the fans

-wire, to attach the motors to power sources.

-remote controlled car controller and receiver.

- 11.1 volt lithium Polymer rechargeable battery to connect to the two fans in parallel.

-duck tape for the skirt

-Thunder AC6 rechargeable battery device

Software List
logview software for recharging the battery http://www.logview.info/cms/e_logview_info.phtml

Time
On average, we each spent about an hour working on the project inside of class. And we each spent about an hour and a half each week working on the project outside of class. Which is a total of three and a half hours working on the project each week per person.

Tutorials
To recharge the battery- http://en.wikiversity.org/wiki/User:Drew_Dollas/enes100/Glorious2/Batteryrecharge

Next Steps
To have two working motors on the back of the hovercraft with propellers on them, to propel the hovercraft forward while the hovercraft is tethered to the generator.