Meetings

Hey everyone!

I'm thinking about our future full-group meetings, we need to make sure we're setting this meeting as a priority. For this to happen, it'd be great if you all could please post your most available time during the week so that won't get crowded out by other stuff...I can still do Thursday evenings if that works for everyone.

Also, subteams should work amongst themselves to find a consistent meeting time. I'd like to put a deadline on finding all meeting times for all teams by this Thursday. Please post them once an agreement is settled.

For this week's meeting, can you all do Thursday at 6:30?

Thanks so much! I'm really happy with the progress we've been making.

Brett

Gate Mechanism

I had an idea to use a servo motor like an arm. All we need to do is get the touch sensor to run into the wall and then that will have the servo motor, with some object attached, to act as a arm and press the button. Then when the gate goes down the touch sensor will be disengaged and the arm will come back down.

Cardboard

Hey,
You guys dont need to buy cardboard for the hovercraft. I have some carboard boxes at home which we can use. Just tell me if you will need them or not.

PS:Is the structure team meeting today or not????

hey guys,
did any of you do the problem set 3 questions??
if u did then how did u do problem 2 part a??

meeting today

hey everyone -

so sorry for organizing this so late. i'm going to the special lecture tonight from 5-6pm, but i'd like to meet after that. what time from 6:15 on can people meet tonight? this is a crucial meeting for our presentation tomorrow, so please make it a priority. thanks everyone.

Skirt Material

I kind of looked up some materials we could use for the skirt. Kyle said most probably we would use a heavy duty trash bag. Here are some other options:
-neoprene coated nylon
-polyurethane coated nylon fabric
- sailcloth
maybe we can also use the shower curtain material well I don't know if that would work

I think I won't be able to make it to the meeting tomorrow. I am only free in the morning between 10 and maybe till 12. You guys will be having the meeting around 6 right?

Batteries for Presentation

For the purposes of the presentation, we decided to use the AA 2600mAh high capacity NiMH Rechargeable battery. We based this decision on this fan:

http://www.sofasco.com/products/dc_axial/d9232.html

The total weight of the cell of 8 batteries should be about .48lbs and the cost per battery is about $1.50..so around $12 for the whole thing.

This is only for the presentation, we might have to rethink the batteries depending on what fans the structural team decides on.

By the way, Pat is free the entire day tomorrow to meet and I can meet between 1 and 3pm or between 6 and 7pm.

g Meeting #2- Cambridge lounge, 3rd floor @6:00pm

• · Kyle made a spreadsheet of calculations and explained it to the group
• · Discussed ideas for levitation fans
• · Discussed types of skirts we could use: bag skirt / wall skirt (air mattress, suspension)
• · Justin is trying to get imaging software to create a design for our presentation
• · Went over types and placement of sensors

o Decided on using ultrasonics

• · Came up with ideas for gate mechanism

o Casing, servo motor, spinning gear to move mechanism with teeth

• · Materials

o Batteries – rechargeable, Li-Ion or NIMH

o Circuits- “switch” (name?)

• · Team dynamics
• · Plans for after the first milestone

PROPULSION FAN

hey guys,
I think Colin did the research about the propulsion fans we can get out in the market I did something different. I basically researched on which type of fan should be used as a propulsion fan.
The propulsion fan should be axial. The benefits of an axial fan are that it provides more thrust and high volumetric flow rate . The levitation fan should be centrifugal because this would generate more pressure and lift the hovercraft.
There are also benefits if the propulsion fan is ducted. A ducted fan provides more thrust and has a smaller diameter than a free propeller. If the diameter is big this would help to catch more incoming fluid and distribute its power and thrust on a larger fluid volume.
Having shorter blades can help to operate the hovercraft at higher speeds.
The disadvantage of a ducted fan is that it is heavy.
A shrouded fan is a good fan because it has a very short ring around the prop to control tip losses.
Here are some websites
http://4wings.com.phtemp.com/tip/tpdduct.html

http://4wings.com.phtemp.com/tip/tpdduct.html

http://4wings.com.phtemp.com/index.html

Batteries

I found a pretty good site for batteries and found a few possibilities that we could use. The real choice is between Li-ion and NiMH. To me it seems that NiMH is the best choice, but we should discuss it at the meeting.

NiMH:

http://www.all-battery.com/aa2300mahnimhrechargeablebatteryflattopformakingpacks.aspx

http://www.all-battery.com/aa2600mahhighcapacitynimhrechargeablebattery.aspx

Li-ion:

http://www.all-battery.com/li-ion18500rechargeable36v1300mah.aspx

Propulsion Fans

I'm having difficulty finding propulsion fans but here are three small fans I found:

http://www.safetycentral.com/bapopihefanw.html

http://www.safetycentral.com/bapopihefanw1.html

http://www.spacesavers.com/batteryfan.html?utm_source=GoogleProducts&utm_medium=productfeeds&tum_campaign=Froogle

Lego products for NXT

Hey everyone!

Here's the website for the different attachments for the NXT. Justin, please take note of the cost so we can get a fair idea of what we'll have left after ordering these primary parts. Thanks!

http://search2.lego.com/?all=u1&cc=US&i=1&l=2057&pt=shop&q=NXT&u=&u1=q

sorry about the link...the hyperlink wasn't working.

Brett

First Team Meeting notes

Hey everyone...here's the first team meeting notes...


ENES100 Team 3
Meeting #1

• Read over Milestone #1 requirements
• Decided that Joe is working on the Gantt Chart
• Brainstormed design thoughts
o Overall design
• 1st design- “guitar pick”, fan in front, more speed than accuracy
• 2nd design- two platforms, brakes
• 3rd design-“volcano”, combination of 1st and 2nd design
o Platform material
o Speed vs. accuracy
o Method to open the gate (Ask Prof. Murphy how much force is needed to push the button to open the gate)
o Uniform air flow – suggested to incorporate something hanging underneath the vent
o Pros and cons of each design
• 1st design: pros-simple and cheaper; cons-control and torque
• 2nd design: pros-brakes, less area, balance; cons-complex, expensive, servo taken, wider
o Voted on a design- “volcano” design
• Next meeting we all need to turn in our money ($35)
• Break up into teams
o Programmers: Justin, John, Colin
o Electrical: Pat, Charlotte
o Structural: Kevin, Joe, Aditi, Brett
o Project Manager: Brett
o Scribe: Charlotte
o Treasurer: Justin
o Design Manager: Kyle
• Next Meeting: Cambridge lounge(?); September 17th at 6:30pm