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Revision as of 19:42, 9 September 2012

Major Stakeholder Analysis

Listed below are the major stakeholders for the retractable light, which include the manufacturer, customer, retailer, and distributor. The manufacturer generally would strive for low cost to mass produce the product for profit. The customer generally would need the product to be low cost, durable, and safe to use since they desire the product quality they pay for. The retailer would strive for low bulk pricing so that they can purchase the product in large quantity to sell to the customer. The distributor generally would need the product packaging to be durable and able to protect the product during the shipping process.

Manufacturer

• Low material costs
• Limited number of parts
• Ease to assemble
• Ability to be mass produced
• Environmentally friendly manufacturing processes
• Easy to package and ship

Customer

• Easy to use and install
• Multiple mounting options
• Low cost
• Durability
• Portable or light weight
• Ergonomic design
• Good aesthetics
• Multiple length adjustment positions
• Waterproof
• Safe to use
• Ability to customize cord length and reel cover color
• Easy to repair or disassemble

Retailer

• Good aesthetics
• Small packaging size
• Good performance
• Low bulk pricing

Distributor

• Low weight
• Durable product packaging
• Space optimized packaging
• Packaging protects product

Product User Study

The MSR MiniWorks Pump operates via an oscillating piston with two one-way valves. A duck valve is inline with the pump head and housing to prevent excessive pressure buildup in the housing. The entire product can be completely dismantled in-field, and can be maintained with little prior knowledge. The design seems very simple yet efficient in its purpose.

Use Flow Chart

Usage
Find the cleanest possible source of water. The intake hose is unwound, and then the intake hose is inserted into the water source. Attach the pump to the water container. Pump water at a steady rate, until container is full. Pull the intake hose out of the water, and pump to clear pump of any additional water.

1. Connect mounting bracket to reel using pin and locking clip.

2. Mount reel to ceiling using screws in shown orientation.

3. Plug reel into nearby electrical outlet.

4. Red indicator light shows that outlet block is receiving electrical power.

5. Grasp outlet block and pull cord out to desired length. Ratcheting mechanism locks cord in position.

6. Plug external device into outlet block and use.

7. After external device is unplugged, grasp extended cord and pull away from reel to release ratcheting mechanism. Internal spring retracts cord back into reel

Mechanical Function
The product contains a lever that is attached to an oscillating piston with two check valves. On the intake stroke, the intake check valve allows water to travel through the water source into the piston. On the compression stroke, the intake check valve is closed and the bottom check valve allows water to be forced through the filter chamber. The filtered water is then sent out of the pump. A duck valve lies between the pump head and housing to prevent a buildup of pressure. If the input flow is greater than the outlet flow, then the spring on the duck valve will compress and pressure will be released.

Exploded View

Intake Hose

Piston Assembly

Preliminary User Study
Our group conducted a preliminary user study and determined that the product was self explanatory for either experienced hikers or anyone with moderate technical know-how (i.e. CMU engineering majors). Our group was able to completely dismantle the product without the use of any tools and easily discern the purpose of each part. This product would only need to be purchased by someone with a lot of experience in hiking and the outdoors, as someone without this experience should not be taking trips during which they won't have access to drinkable water. Therefore, nobody should be using it without any prior knowledge.

There are many well-thought-out features which exhibit themselves through simple use. First off, the outlet of the pump is threaded the same size as a Nalgene bottle, so that the pump can sit directly on the bottle and there is no risk of contamination. The included cap for the outlet of the pump also serves to reduce contamination when not in use. The rubber hosing wraps around the pump housing and is secured by a small c clamp in the handle. This serves to not only hold the handle down when when not in use (and prevent incidental breaking), but the c-clamp is properly sized so that it squeezes the hosing closed to prevent excess contamination. Finally the handle is contoured to fit well with the averaged sized in a comfortable pumping position.

Not many issues arise when using the MSR water pump. The most notable problem lies in the fact that the pumping action is cramped and requires several minutes to fill a hiking-sized water bottle. If there were a way to reduce the pumping effort required while keeping the small footprint of the product, it would probably be very beneficial. The only other foreseeable issues are broken parts or a clogged filter, which we didn't encounter and couldn't simulate during this study.

Parts List

Item Number	Description	Quantity	Mass (g)	Function	Material	Manufacturing Process	Image
101	Duckbill Valve	1	0.5	Acts as a check valve, so that water can be pumped in through the hose, but not out	Plastic	Injection Molding	Duckbill Valve
102	Hose Barb Washer	1	<1	Sits between the duckbill valve and the spring	Steel	Purchased	Hose Barb Washer
103	Hose Barb Spring	1	2	Acts as the pressure relief in the check valve	Steel	Purchased	Hose Barb Spring
104	Hose Barb O-Ring	1	0.5	Prevents water leaking from the hose barb	Rubber	Purchased	Hose Barb O-Ring
105	Hose Barb	1	3	Connects to the hose	Plastic	Injection Molding	Hose Barb
201	Hose	1	44	Serves as the inlet hose of the contaminated water	Rubber	Purchased	Hose
202	Buoy	1	<1	Prevents the hose from sinking to the bottom of the water source	Foam	Foam Molding	Buoy
203	Debris Cage	1	11	Acts as a pre-filter and as a weight so that the hose stays below water	Steel	Purchased	Debris Cage
204	Intake	1	1	Water inlet, and also holds the foam filter	Plastic	Injection Molding	Intake
205	Foam Filter	1	<1	Acts as a pre-filter for large particles	Foam	Foam Molding	Foam Filter
301	Pump Housing	1	56	Contains piston and hose barb assemblies, and connects to filter	Plastic	Injection Molding	Pump Housing
302	Piston	1	9	Acts as the pump by drawing in and pushing out water	Plastic	Injection Molding	Piston
303	Piston O-Ring	1	2	Prevents water from getting past the piston	Rubber	Purhcased	Piston O-ring
304	Piston Pivot Sleeve	1	1	Connects piston to the handle	Plastic	Injection Molding	Piston Pivot Sleeve
305	Piston Pivot Pin	1	<1	Connects piston to the handle	Plastic	Injection Molding	Piston Pivot Pin