User:Andyha0933/portfolio/enes-100/Project 2

Week 1
Tasks:


 * Interview John of operation of large machine
 * Measure voltage of large Wimshurst machine
 * Test the large Wimshurst machine with box

Doing:


 * To operate the large Wimshurt machine, I have to first charge a PVC pipe with silk by rubbing the pipe with the silk. Once the pipe has a strong static field, I have to hold it up to the disk of the Wimsurst machine, while the machine is in motion. If done correctly, the static charge will transfer onto the machine.


 * The voltage of the large Wimshurst machine is ~15k-20k volts, which is considerably higher than the small machine, measured at 4k-5k volts. This was measured using a high voltage probe connected to a multimeter, set in DC Volts mode.


 * I Wired Wimshurst machine to box in same manner as the small one. Resulted in much greater amount of bouncing, whereas the balls were actually bouncing and hitting the ends. However, there were still certain balls that did not bounce. The problem was that the aluminum foil was wrapped around the styrofoam in a disorderly manner, compared to the ball that actually bounced, which was uniformly and neatly wrapped around a perfectly spherical styrofoam ball.


 * Also noticed that after a while, Wimshurst machine would lose a significant amount of output, or not output enough charge at all. The output was last measured at 15k-20k volts, which is considerably low, given the size of the large machine in comparison to the smaller one. John has said that the machine may be dirty, which could be affecting the machine by making it harder to start and decreasing its voltage output.

Next Steps:
 * Clean machine and measure voltage output

Week 2
Task:


 * Clean large Wimshurst machine
 * Measure voltage output

Doing:

Dis-assembly process:


 * 1) 1. Remove the static brushes. These are on the crossbar on the outsides of the wooden frame. Loosen wingnut and pull off.
 * 2) 2. Remove the bolts holding in the crossbar. These come out freely and requires no turning.
 * 3) 3. Remove the crossbar. Hold up the disks and pull out the crossbar.
 * 4) 4. Remove the disks. The disks are attached to the bands so pull the bands off before pulling out the disks.

Cleaning process:


 * 1) 1. Sprayed the insides of the disks with multi-purpose cleaner and wiped off with paper towel
 * 2) 2. Sprayed some cleaner into paper towel and wiped off all aluminium foil parts: brushes and pickup points.

I was not able to measure the voltage of the machine because I could not start it. It may be due to the weather, I am doing it incorrectly, or the cleaner is affecting transfer of the static charge.

Next Steps:


 * Determine the reason it is so difficult to start the machine
 * Measure the voltage output of the newly-cleaned machine

Week 3
Task: With the Wimshust machine suddenly nonoperational, I was to find out the reason.

Doing: While reading over past team pages that used the machine, I came across the term Bonetti Machine on this team page. After a quick search on Google, I came across this website. According to this website, the exact way to start the machine is not to just hold a static-charged PVC pipe up to the disk, but to hold it exactly opposite to one of the static brushes. After testing it, it was confirmed that this was the problem, as I was able to start it 100% of the time doing it this way.

After that, I encountered a new problem: the Bonetti machine was discharging somewhere in the middle of the disks, making it so that the charge was not transferred to the box. I hypothesized that it was the paper washer in between the disks conducting the charge. The reason I think this is because when I took the machine apart the first time, I wasn't careful to make sure the washers were centered on the crossbar. I took apart the machine and glued the pieces of the washer back together, and put it back in. Due to the lack of time, I wasn't able to test if this worked.

Next steps: Test operation of the Bonetti machine to see if the charge is now being carried back to the ends of the machine

Week 4
Task: Document operation of Bonetti Machine

Doing: Steps to operate Bonetti Machine:


 * Ensure no brushes are making contact with the disks.
 * Before starting, make sure the disks rotate in opposite directions when turning handle
 * To start, rub a medium-large diameter PVC pipe with a silk cloth until there is enough static charge on the pipe to cause hairs on your face to stand up
 * Hold charged PVC pipe opposite of one of the static brushes while turning handle. You will know if the machine is charged when you can hear the static in the machine.

Troubleshooting:
 * If it is not starting, try changing which static brush you are holding the PVC pipe against, or change the direction of which you are turning the handle.
 * If the charge seems to be getting lost in between the disks, change the direction you are turning the handle.