Final Report

Team Efficiency #8

George Tratras, Carmen Rosporski,

Nathan Lutz, Parth Patel

Efficient Grid

Mission Statement

Our product is a ground tarp used for the construction of and in combination with the

HESE greenhouses. We had to make sure that our design would meet the needs to the HESE

students. They needed a grid to aid in the setup of the greenhouse. Our grid had to last at least 5

years, take under ten minutes to set up, be under 50 dollars, and most importantly, accurate. Our

product will benefit the HESE team and anyone involved with the construction of the greenhouse

by trimming the time it takes to layout the dimensions of the greenhouse. Our main business goal

is to have an efficient product for the HESE students and the people of Sierra Leone to help set

up greenhouses. The primary market for the tarp is the HESE team for their greenhouse kit, as

well as the people that choose to purchase the greenhouse kit. The secondary market are the

consumers of the products created by the greenhouse: A more efficient greenhouse means better

product yields and product sales. The main assumption for our grid design is that the tarp will be

portable, durable, simple to use, water proof, maintenance free, and that the people constructing

the greenhouse will have the tools necessary to put the rebar in the ground. The stakeholders for

the grid are the manufacturer, the user, the people that are harvesting the crops, and the people

consuming the crops.

Concept Development Summary

When we were given the opportunity to help the HESE team we knew we wanted to

construct a grid. Figure 1 shows the early stages of our design idea. We also knew it was crucial

to get a background of where our product would be used, Sierra Leone. We started to collect

information we thought would be beneficial to have when deciding how we were going to

construct our product. For instance, we gained knowledge on how hot it can get in Sierra Leone

and that was mandatory information to understand when creating our prototype. We also gained

information about the terrain and the government of Sierra Leone. After the civil war of Sierra

Leone, the land was destroyed. This is when we realized our product had to be durable under

harsh conditions; however, before we even thought about prototyping we knew we had to start

brainstorming. Some of our earlier ideas consisted of attaching a plywood type of grid to a tarp

with stakes. We came up with these ideas with the hopes that our tarp would be consistent due to

the rigidity. Figures 2 and 7 demonstrate the tests we used to determine how consistent the setup

was. We desired something that could fold up nicely, but when unraveled it would maintain the

rigidity of a piece of wood. The portability tests are depicted in figures 5 and 9.

Figure 1 shows some of early stage drawings trying to get a solid

understanding for how we wanted our prototype developed

Figure 1

Test Report Summary for Prototype #1

Tests performed Results Observations/concerns

Cost -Track what was bought and recycled -spend less than 10 dollars would pass

Only materials we didn't recycle were hot glue and duct tape PASS

To pass we needed to spend less than 10 dollars and we did.

Durability -hair dryer test -weight test -no disturbances with heat and a weight test of 5 pounds without rip would pass

Held hair dryer of tarp for 2 min (160-165 degrees Fahrenheit) Put two books (5.05lbs) and lifted tarp up PASS

We saw no disturbance in the tarp by the hand dryer and the tarp was able to withstand the weight of 5.05lbs.

Setup time - Time each team Everyone set it up We were very happy

member and see how long it took to set up the product. Under 3 min would pass

under 30 seconds PASS

with these results because setup time is so crucial. We observed that our tarp was under our pre-set time of 3min.

Portability/weight -weight of the tarp and book bag test -If it weighed less than 5 pounds and fit into a book bag it would pass

Our tarp weighed .5lbs and was able to fit into a traditional book bag PASS

We weighed our prototype on a scale and found it was very light. It was harder to fold than we expected but it still fit into a traditional book bag.

Accuracy -test our grid and see if it was accurate. Accurate to 1cm would pass.

Our tarp was not accurate to 1cm FAIL

Our tarp was a lot less accurate than we thought. We performed this test many times and found that on average we were accurate to 12cm

Ease of use - Have somebody else layout our grid without any of our help. If he or she could set it up under 3 min it would pass.

Our TA was able to set up our grid under 30 seconds. PASS

We thought if someone else outside of our group could set up the tarp under 3 min it was an easy to use product.

Figure 2 shows team 8 performing an accuracy test

inside a dorm room with a small scale grid.

Figure 2

Figure 3 shows someone outside of Team Efficient

trying to reconstruct the grid in the engineering and

design lab. This secured the ease of use test and set

up time test.

Figure 3

Figure 4 shows the team performing a durable test.

Prototype 1 was able to hold 5.05 pounds in the

engineering and design lab.

Figure 4

Figure 5 demonstrates how easy our prototype could

be compacted down and how portable it is. This test

was performed during class in the engineering and

design lab.

Figure 5

Concept Refinement Summary

After testing was concluded for prototype 1, our group started to discuss our results. We

found that even though our prototype passed many of our tests, there was still plenty of room for

improvement. For example, looking at our testing table above, we felt that our tests could be

more rigorous, which would help reveal more problems in our next prototype. Furthermore, in

figure 3 we had an outsider try to set up the tarp as per our ease of use test but found that just one

person was not enough to precisely determine if our product was easy to use. Our change was to

have multiple people try to set up our prototype instead of just one. Using this new knowledge

we decided to make some key changes to our prototype. First we decided to include removable

rods instead of the already built in wooden rods. In figure 8 the rods are being put back into the

tarp. This change was included to allow our tarp to be more portable and easier to roll up. The

idea was to be able to insert these rods into slits on the tarp when using it to lay out land and then

to quickly take them out to when finished. Another important change was to make smaller holes

by using washers instead of shower curtain rings. The washer design is shown in figure 7. This

will vastly improve the accuracy of our tarp, which was easily the worst aspect of our first

prototype. If you look at figure 2 located above, it can be seen that our first prototype was not

even the intended length. Last but not least we decided to keep our idea of using a triangular tarp

and flipping it instead of a full square. The benefits of using just a triangular piece of tarp we

believed provided too many benefits for us to just scrap it. The triangle design is demonstrated in

figure 7.

Test Report Summary for Prototype #2

Tests performed Results Observations/concerns

Durability -Throw against wall

-Hold hand dryer

over tarp for 10

minutes

-Soak in water for 10

minutes

-Put 5 pounds on top

of tarp and lift

No breakage resulted

from throwing against

wall. Was able to

hold 5 pounds even

though we had one

rod snap. Was able to

withstand heat and

water.

PASS

After the tarp had been

put through the many

hardships, we noticed

no tears or rips. In

addition, the poles were

not wet nor were they

difficult to remove.

One thing we did notice

was that ours rods were

fragile, with one

snapping under weight

test.

Set Up/ Ease of Use -Have 3 people of

different college

majors and different

backgrounds try to

set up our tarp under

2 minutes

Carmen and the TA

were both able to

assemble the full grid

in under 2 minutes.

Additional Testing

needed.

PASS

At first the participant

looked confused about

what to do but within a

few seconds they were

well along their way of

assembling the tarp

Accuracy -Must be accurate to

1 cm

We laid out grid and

ran an accuracy test 5

times. The tarp was

accurate to 1 cm all

times.

PASS

Must line tarp up across

the hypotenuse perfectly

to achieve accuracy to 1

cm

Weight/Portability -Must weigh less

than half a pound

-Compact the tarp to

less than half a foot

without the rods

Weight was .5 lbs

Compacted to less

than half a foot

without rods inserted

PASS

After removing the

rods, the tarp easily

folded up and was

extremely compact.

Safety -Run hands along

edges

-Ask TA if prototype

looks and feels safe

No sharp edges to cut

anyone and TA on

duty at night said it

looked safe to her

PASS

Seemed extremely safe

although who knows

how safe it could be

after months of use

Affordability -Cost under $15 Total cost of It may be difficult to

materials for

Prototype #2 was

$12.23

PASS

make the full scale

model be under a $50

budget.

Figure 6 shows two of our teammates

conducting a durable test in the engineering

and design lab.

Figure 6

Figure 7 shows how we performed the accuracy test for

the second prototype. We laid out our grid and saw if it

matched up our preset holes. This test was performed after

class in the engineering and design lab.

Figure 7

Figure 8 shows one of the many tests we kept from prototype

one. You can see a girl reconstruct our grid without any help

from us. This was important because we won't be using our

grid. Someone else in Sierra Leone would be. They need to be

able to use our prototype easily. Since our test subject (this

girl) was able to use it without our help. As well as 4 others.

This test was performed outside of class at various locations.

This picture was taken at the engineering and design lab.

This test was a pass

Figure 8

Figure 9 shows Parth Patel folding our prototype to

demonstrate the compatibility of our prototype 2. This test

really demonstrated how small our grid could be folded

down to in order to be transported from one location to

another. This test was also performed outside of class at the

engineering and design lab.

Figure 9

Cost Analysis

Our second prototype easily met the cost range for the HESE Greenhouse Grid. For the

most part we used recycled materials in the construction of our design. The costs for the

prototype were for the ¾” wooden dowel rods, the tarp material, and the washers that were

incorporated into our design. The estimated price of our final prototype is about $15.

Washers-$0.29 x 10 + Tarp-$6.58 + Wooden Dowel Rods-$.55 x 5 = $12.23 (lowes.com)

Based on this design, a full-scale model could easily meet the costs of the HESE team.

However our final product would come with some changes. The sleeves that hold the poles

would be stitched in. Next, the final grid would use grommets instead of washers to locate the

holes for the rebar. Finally, the poles themselves would be made out of ¾” PVC pipe all of

which would add to the total costs of the design. The expected price of the final product would

be the following: Grommets-$4.38 (10 pack) + Tarp $36.33 + Thread $.32 + Pipe 6x$2.02 +

Fittings 5x$.38 = $55.05 (lowes.com). Unfortunately, our budget is $5 over but there are

different materials and techniques which could cost less money. Upon calculating the costs of

our full design, the second prototype could not be built for full scale gridding.

User Guide

Below is a copy of our illustrated set of instructions for setup, assembly, and use of our

tarp. It contains simple worded instructions, but mainly relies on the illustration aspect through

various directions and arrows that illustrate the setup in the simplest way possible to ensure ease

of assembly for the operator, even if he/she does not read/write English.

Redesign Ideas/Thoughts

During presentation day we presented our product pitch and were judged by the HESE

coordinators. We received essential bits of constructive feedback. One of the main points about

our design that was addressed by a HESE coordinator regarded the length of the longest “dowel

rod” used in our design, and his question was how long it would be in the full-scale model. This

was one of the points we didn’t really consider for the full-scale model, as our 1/6th scale

prototype incorporates two 1 meter long single piece dowel rods for the longest sized stability

rods in our design. The problem is that in the full scale version of the rods, they would be 6

meters long a piece, this obviously is a very long rod to be able to transport practically, so we

had to reconsider a new design or material for that part. Our solution for this problem is to use

PVC piping as the stability structure. We can make many smaller pieces that attach to one

another through the use of connectors and couplings. These couplings and connectors can be

installed in the final length we need for the final full-scale product. We also plan to use ½ inch

diameter PVC, as this provides ample stability and rigidity for the size of the full-scale model

(homedepot.com). Another point made by the HESE coordinators was “What would happen if

the sleeves containing the stability rods ripped or is torn?” We gave it some thought and realized

it would be better in the final project if we would sew the sleeve on to the tarp. This sewing

method is a traditional method that is durable, waterproof, and heat resistant. Another benefit of

stitching the sleeve onto the tarp is that if the stitching tears or needs repair, a local shop or a

person who has the knowledge to be able to sew in or make that repair, could do so readily,

easily and quickly maximizing the use and practicality of this design.

For the redesign that our group would suggest to the HESE students, and what we

envision for our third prototype and hopefully final product is the implementation of the ½ inch

diameter PVC pipe as the stability rods. This PVC pipe is pieced together with various couplings

into the final piece length. Finally, it is inserted into sewn sleeves at the time of assembly and

setup. Other than that we are going to use actual metal grommets with a legitimate grommet

punch so that it is held together with a stronger bond that is essentially more durable for this

product’s application. The above description is our “dream” design for our prototype and final

product at this stage. This design allows for precision, easy setup that does not require any

external tools or complex skills, and allows for portable transportation and compact space

utilization.

http://www.homedepot.com/p/Unbranded-1-2-in-x-10-ft-PVC-Sch-40-Plain-End-Pipe-

530048/100113200 - PVC Pipe supplier

http://www.lowes.com -Cost Analysis

"Lowe's Home Improvement: Appliances, Tools, Hardware, Paint, Flooring." Lowe's Home

Improvement: Appliances, Tools, Hardware, Paint, Flooring. N.p., n.d. Web. 03 Mar.

2015. <http://www.lowes.com/>.

"1/2 In. X 10 Ft. PVC Sch. 40 Plain-End Pipe-530048 - The Home Depot." The Home Depot.

N.p., n.d. Web. 04 Mar. 2015. <http://www.homedepot.com/p/Unbranded-1-2-in-x-10-

ft-PVC-Sch-40-Plain-End-Pipe-530048/100113200>.