Nov 30th- GRNG 201/301

Bicycle Shelter-

Metal sheathing vs plexiglas-- see through vs metal. Can we add solar panels to the roof(supported by steel structure)?

Mr. P. knows a gentleman from the City of Newton who can assist with welding.

Do we need engineering approval? City or others can evaluate.

Unit could be attached to the concrete using expansion bolts- will discuss with principal/assistant principal.

Aquaponics group-

Group should work as smaller sub-groups--- fish feeder, tanks, etc.

Fish feeder group began fabricating feeder mechanism from dowel and block,

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Greengineering has been accepted to LearnLaunch Conference for February 3rd- need to put together exhibits-- soap demonstration and samples, presentation on soap-making with educational component- see for example http://www.labmuffin.com/2014/08/make-your-own-soap-part-1-the-chemistry-behind-soap-making/  .

Need to specify plastic containers to hold ingredients- will check at the Container Store.

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Tested Wind turbine(made with closed-cell foam hub) with USB Charger-

Attached 5V Drok charger placed a significant load on rotor- slowed considerably. 

Blue LED did not put as much of a load on motor/generator.

Nov 30th- GRNG 101

The Wikispaces team pages( https://greengineers.wikispaces.com/101 ) need to be updated at least once per week- Grades will be based to a significant extent upon project documentation in the wiki.

This week's post must include an impact goal.

We will have a weekly meeting for progress reporting.

If you need materials--look around to see what is available/on hand already- a major theme of Green Engineering is

• Recycle/Upcycle
• Reduce
• Reuse

This could include using cheaper alternatives- a plastic 20 gallon container from Home Depot vs a $2,000 fish tank from an aquarium supplier. Check the Wiki for older system ideas/materials that could be re-used.

Bicycle group-- talk to Mr. Peloquin if you need parts.

Materials Group- Need to put together a proposal for review by the principal/assistant principal; should be presented first to the class group.

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To upload cellphone photos to Wiki, one method is to upload the photos to the Google Drive app on your phone, then upload them on your laptop from Drive to the Wiki- see https://learnwikispaces.wikispaces.com/Insert+Pictures for details on posting photos to Wiki.

Insert Pictures

 Edit 0 3…

Upload an Image or File

1. Edit a page
2. Click the picture (a tree) on the Editor
3. Under Upload New File choose Browse...
4. Browse your computer for the picture and click OK/Open
5. Click Upload

The picture or file will now be uploaded.

Insert Picture onto page

1. Put your cursor (in the page) where you want the image to go
2. Double-click the picture
3. Picture will insert into page
   
4. Edit Image Properties (if you don't see properties, re-select the image)
5. Deselect the image
6. Save page

Insert File (link) onto page

1. Put your cursor (in the page) where you want the file to go
2. Double-click the file
3. File link will insert into page 
   

   MacSwitchClasses_May09.pdf
   

   • Details
   • Download
   • 422 KB
4. Save page

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Aquaponics group-

   Obtained zero? nitrate reading using API kit-- retested using test strip- gave positive nitrate reading

Made/reused rafts:

Discussion- Urea vs Nitrates:

Many algae lack urease enzyme which is needed to metabolize urea. Most algae media contain nitrate vs urea, as bacteria found in soil are needed to metabolize urea.

Bicycle Group-- needed sawdust to make wood filler for hole. Also needs to fasten sides together.

Materials group finished and tested watering prototype:

Nov 29th XPlore- Kinetic Sculpture

Introduced transitioning from windpower project to Kinetic sculpture-

Wind turbine project should have showed that increasing the number of blades slows the speed of the rotor, but increases the amount of power that can be extracted from the wind-

see http://www.learnengineering.org/2013/08/Wind-Turbine-Design.html--

However, increasing the number or length of blades marginally increases efficiency, but results in other problems-

Effect of Number of Blades

As the number of blades in the wind turbine increases aerodynamic efficiency increases, but in a diminishing manner. When we move from 2 blades to 3 blades design efficiency gain is about 3%. But as we move from 3 blades to 4 blades design, efficiency gain is marginal.

Fig.1 Efficiency gain as number of blades in wind turbine is increased

As we increase number of blades, cost of the system increases drastically. Along with that mechanical design of blades also becomes a difficult affair. With more number of blades, blades should be thinner to be aerodynamically efficient. But blades with thinner portion at the root may not withstand bending stress induced due to axial wind load. So generally wind turbines with 3 blades which can accommodate a thicker root cross-section are used.

Fig.2 Wind turbine blades have got thicker root to withstanad huge bending moment induced

Blade Length

Next big factor affecting performance of wind turbine is length of the blade. As we discussed in first video lecture, power extracted by the wind turbine varies according to this equation. So it is clear that, a longer blade will favor the power extraction. But, with increase in blade length, deflection of blade tip due to axial wind force also increases. So blind increase in length of the blade may lead to dangerous situation of collision of blade and tower.

However, due to technical issues( loose rotor blades, etc.) this was not always clear.

Showed Design Squad video, 'Blowin in the Wind'



Students task will be to design a small prototype that shows what it will look like, then build a larger one that will both be artistic and produce power.

Discussed with Mr. P. whether a system that produces power can also be sculptural/artistic.

Showed Strandbeest Video:
https://www.youtube.com/watch?v=PuxtdylbwVs

Linkage Mechanism:
http://www.mekanizmalar.com/theo-jansen.html

Instructables:
https://www.instructables.com/tag/type-id/?sort=none&q=kinetic+sculpture

Nov 28th- GRNG 201/301- Progress reports

Plastics Recycling

Short-term goals:

• Need to find more efficient ways of cutting up plastic bottles
• Collect more plastic milk jugs
• Make another 'pennyboard' deck
• Figure out a better way to melt plastic- use an oven?

Long-term goals-

• Obtained a plastic shredder
• Improve efficiency at melting/ovens

Road Blocks:

• Get trucks and wheels for skateboards( see Amazon for examples)
• Need more( clean!)plastic milk jugs- need issue solicitation for materials

Bike Squad

Short-term goals accomplished:

• Bicycle clamp perfected for repair stand
• Improved mechanical advantage of bike stand, stronger structure
• Drew circuit schematic for music bike
• Improved bike stand adjustability

Long-term goals accomplished:

• Bicycle repair stand built

Road-Blocks:

• Structural integrity of bike stand
• Approval
• We need supplies

Aquaponics Group

Short-term goals accomplished:

• New system design
• Restarted old large system
• Completed a water cycle in our tank
• Prototype for auto fish feeder
• Gathered wood from pallets to panel tank

Long-term goals accomplished:

• We are still in the short-term phase

Road-Blocks to progress:

• Getting off-task/losing focus
• Killing fish
• Killing plants
• Not having enough wood
• Christmas music
• Messing up grow-bed water flow
• Interpersonal conflicts(?)

Needs:

• Fish
• Pallets

Soap Group

Short-term goals accomplished:

• Make soaps from one oil to determine individual oil properties
• Create literature that conveys the message of our project
• List materials that we need

Long-term goals accomplished:

• Prototype one soap recipe to a good formula, and produce a large batch
• Presented the making of soap to a semi-large public audience

Road Blocks:

• Waiting for materials to arrive
• Keeping ourselves busy while we wait for materials

Items for Mr. Peloquin-

• Our project needs successors to continue after we leave
• Our success this year should involve making formulas and pushing out a large quantity of soap
• We need to create a successful soap-making kit

Mr. Dietz

Short-term goals accomplished:

• Rebuilt Weebly site to be more user-friendly, especially for outside public- course outlines, detailed project descriptions, blogs, tools, resources, etc.
• Edited substantial new content for site- links, images, video
• Rebranded Weebly site:  http://greengineers.org
• Created new blog http://greenengineeringdietz.blogspot.com/ with over 70 detailed posts, including photos and videos
• Set up and stocked electronics/Arduino parts section
• Organized tool section, improved tool supply, especially for electronics,sanding, screws, wrenches, and drills
• Downloaded, printed, mounted, and posted useful engineering posters from MIT D-Lab and Nu-Vu
• Provided technical assistance to student projects Xplorers, 101's, 201's

Long-term goals:

• Increased traffic to site
• Became conversant with Greengineering curriculum

Road Blocks:

• Need more feedback from student and teacher users of Weebly site to make further improvements
• Need to improve purchasing procedures to make supportive of project-based learning( i.e., shorter turn-around time).

Mr. Peloquin

Short-term goals accomplished:

• 4 student projects in process for 201/301's, plus Xplore projects
• Each team has made a SmartSheet Gantt chart to outline their project
• Each team has well-defined goals
• 201's have started a new student blog http://greengineering1.blogspot.com/ 
• Website has been updated
• Organized evaluation of real-world prototype( SparcWire)
• Ordered project supplies

Long-term goals accomplished:

• 201/301 Team exhibited Greengineering at  Mini-MakerFaire

Road-Blocks:

• Student teams often think that they can come into Greengineering lab and just hang out; will be instituting weekly Design Reviews to help keep groups on track; implementing student-driven projects requires a change in mindset.
• Teams not keeping an eye on Gantt Chart schedule
• Teams not getting feedback before building- soliciting and incorporating user feedback is key to the Design Thinking/Engineering process:

Additional information:

• Teams need to stay on track, and ask for help when they are off track.

Nov 23rd- 201's- Bicycle Stand; issues with Sparcwire evaluation

Bicycle Team-

Added reinforcements to bicycle stand; better able with support weight of bicycle.

Sparcwire Evaluation-

Sparcwire( http://sparcwire.com  ) product evaluation- System is time-consuming and of questionable utility. Manual tagging of sites is not effective.

Even after watching several videos, it was difficult to figure out what the site ia all about.  And what the heck is a 'certified cultural curator'?




However,  evaluating an ineffective product or service is not a waste of time.

 I always find that I learn much more from describing exactly why a failure is a failure than from looking at a successful product.  Did the company begin by evaluating the user's needs? Did the sales rep develop a relationship with the customer? Is the product confusing?

Very few, if any, inventions or services worked the first time- or even the third time...

At all stages of the design process, feedback is essential-

Nov 23rd- Centrifuge Repair

Added cord cap to old power cord from water heater, creating a new extension cord.

Began rewiring algae centrifuge system, which had many frayed wires.  Added Romex connector to entrance box on motor. I was confused by the wiring, as it had two green wires.

Cord                Motor       NEMA

White               Blue          T1

Green1             White        T2

Black               Orange       T3

Green 2            Frame(Ground)

I realized the motor is a 220V  motor, which means I will need 4-conductor cord+ a 4-pin plug and socket to wire it.

Motor speed controller needs to be enclosed in an electrical box. See https://www.automationdirect.com/static/manuals/gs1m/gs1m.pdf for more information.

Nov 23rd- GRNG 101's- Watering device, wicking system, determining nitrate concentration.

Plants Group:

Ben worked on Prototype of  pole-mounted watering device using bamboo poles. He used a hacksaw and the portable sander to smooth the bamboo:

Duct tape was used to fasten the assemblies:

     TA-DA!

Other part of plants group attached fabric to the bottles to hold in the soil:

I suggested creating a wicking system that would raise water from the lower reservoir up to the soil above:

See http://www.bottlebiology.org/investigations/terraqua_main.html for additional information.

Algae Group:

Mixed up nutrient solution using 15 gram pod in 1 liter of water, and tested for phosphate, which maxxed out:

Will need to review calculations with group:

1 pod= 15 grams

Pod = 5.9% nitrate, so contains about 0.059 x 15= 1 gram of nitrate.

If pod is dissolved in 1000 ml of solution, solution contains 1 part per thousand= 1000 parts per million of nitrate.

To get a solution containing 20 ppm of nitrate, mix 20 cc of first solution into 1000 cc of final solution.

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Tap water contains chlorine, which kills algae. Chlorine can be removed with reverse osmosis filter, or by dissolving potassium metabisulfite into it. One campden tablet is enough to dechlorinate 20 gallons of tap water. Pros: Very fast - as soon as the K-meta is dissolved in the water and stirred, the water is dechlorinated.

Question about relationship of  nitrates, nitrites, and Urea- see

http://blog.brightagrotech.com/nitrogen-in-aquaponics/

Nov. 22nd- Exploratory- Work on Wind turbines

The Xplorers continued their work on the wind turbines, with mixed success:

Foam hubs fail after multiple uses, so that the turbine blades will not maintain the correct angle.

Use of hot glue causes foam to melt, creating cavities.

Should create an alternative turbine hub system- perhaps hot glue vanes to cardboard, which is then velcroed to a wooden hub piece.

Will try using closed-cell foam cylinders attached to cardboard.

Nov 21st- GRNG 201- Aquaponics, plastics shredding, bicycles

Aquaponics group-

Active discussion of design options. Discussed making a small system that could be provided/sold(?) to elementary schools, with an educational component.

Bicycle Group-

Worked at reinforcing bicycle stand:

Began prototyping scale model of bicycle shelter:

Plastics Team-

 Tested out shredding milk jugs with paper shredder.

Experimented with melting shredded strips in fusinizer.