Soda gun

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Revision as of 18:39, 1 February 2014 (view source) Epa@andrew.cmu.edu (Talk | contribs) (→Manufacturing) ← Older edit		Revision as of 18:42, 1 February 2014 (view source) Epa@andrew.cmu.edu (Talk | contribs) (→Design for Environment [DFE]) Newer edit →
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		+	==Team Members==
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		+	Elle Allen: DFMA Lead
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		+	Julien Locher
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		+	Taryn Monteleone: DFE Lead
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		+	Dan Murby
		+
		+	Christy St. John

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Revision as of 18:42, 1 February 2014

Contents 1 Executive Summary 2 Use Study 3 Bill of Materials 4 Design for Manufacturing and Assembly [DFMA] 4.1 Manufacturing 4.2 Assembly 5 Failure Mode and Effect Analysis [FMEA] 6 Design for Environment [DFE] 7 Team Members

Executive Summary

Use Study

1. What are the stakeholder needs?

What attributes does the user need for from the product? What attributes does the retailer have?

The User/Bartender:

This product will be principally used by bartenders at commercial food and drink establishments. This product allows for multiple soda types to be served at a quick pace with uniform accuracy. The user expects that the product will complete the task at hand, namely separating different soda type.

Some key qualities that the bartender expects are:

• Responsive, fast serving when each button is pressed
• Easy to understand button configuration and operating procedures allowing for operation with little training and muscle memory
  • Typically, these types of devices are built in an industry-standard layout.
• Any hoses or pumps must reach the full range of bar in case other employees need it
  • It may be common for multiple bartenders and/or waiters to need access as well
• Easy to repair, easy to maintain, easy to clean
  • Avoiding contamination issues will allow the establishment to be healthy and satisfy customer needs (no one wants a coke with orange soda residue in it)
• The user expects durable quality
  • During peak hours, the gun may be thrown around, dropped etc.
• The user would like the product to be “Ergonometricly” friendly
  • Over the course of a long shift, the user may hold and operate the gun for a long time
• Most products come with a holster that allows for storing and draining when the gun is not in use. The product must fit snugly in the holder to prevent any jostling, but also accessible enough to allow for easy removal and use, ideally with one hand.

The Restaurant/Bar Owner:

From the perspective of the owner, this product should be cheap to manufacture, require little maintenance, and be durable enough to last a long time after purchase. In many cases, the beverage company itself is responsible for the installation and maintenance of the gun, but if the owner can avoid these costs, he would be interested.

The Retailer:

The retailer of the gun wants the product to be aesthetically pleasing, which encourages customers to buy the gun and use it at their bar. He also expects the gun to be of high-quality to support his business, which may include water-resistance and consistent flow-rate. The gun should be as compact as possible while performing the task at hand to allow for easier shipping, and giving bars the greatest amount of room to operate in, without bulky equipment in the way. Finally, the retailer wants the product to be easily explained and easily integrate-able into a bar. This allows for easier sales and a more diverse customer base.

2. How the product works mechanically

- Press a button, and it opens a valve connected to a type of soda. The gun then mixes carbonated water and the designated syrup and distributes the mixture into a cup.

- The strength of the syrup in the mixture and what types of drinks are available are customizable and adjustable, allowing for the user to create a set up that best works for their demand and beverage company contracts.

3. How the product is used (step by step)

1. (Set-Up)
2. Learn which buttons go to each soda
3. Pick up gun
4. Point nozzle to cup
5. Press appropriate button
6. Fill to required level
7. Re-holster gun

Bill of Materials

Part #	Part Name	QTY	Weight (g)	Function	Material	Manufacturing	Image
Soda Gun Sub-Assembly
1	"Round head 1/2" Length 1/8th" Dia Phillips"	2	<1	Fastens button panel	Stainless Steel	Std Purchase Part
2	Elliptical Soda Button (Top)	2	<1	User input button for soda, designates type	Plastic	Injection Molded
3	Eliptical Soda Button (Bot)	2	<1	Translates input key face to release soda	Plastic	Injection Molded
4	Circle Soda Button (Top)	8	<1	User input button for soda, designates type	Plastic	Injection Molded
5	Circle Soda Button (Bot)	8	<1	Translates input key force to release soda	Plastic	Injection Molded
6	"Flat head 1/4" len 1/8" dia philips"	2	<1	Fastens panel to gun body	Stainless Steel	Std Purchase Part
7	Plastic Washer (For Part #6)	2	<1	Spacing	Plastic	Injection Molded
8	Small Butterfly Clip	2	<1	Aligns button to pin valves	Stainless Steel	Die Cast, punched
9	Large Butterfly Clip	2	<1	Aligns button to pin valves	Stainless Steel	Die Cast, punched
10	Button Panel, blue, 10 button	1	12	Holds all buttons in place	Plastic	Injection Molded
11	"Round head 1" len 1/8" dia flat screw"	2	<1	Fastened gun to hose base	Stainless Steel	Std Purchase Part
12	"Round head 1/2" len, 1/8" dia flat screw"	2	<1	Fastened gun to hose base	Stainless Steel	Std Purchase Part
13	"Hexagon, 7/8" len, 1/8" dia threaded head (Receives Part #11)"	2	<1	Fastened gun to hose base	Stainless Steel	Std Purchase Part
14	Nozzle caps, clear plastic	10	<1	Reduces hose diameter into gun base	Plastic	Injection Molded
15	O-ring, rubber	10	<1	Seals hose to gun base	Rubber	Std Purchase Part
16	"Round head, 1/4" len, 1/8" dia, philips screw"	5	<1	Fasten back panel to gun	Stainless Steel	Std Purchase Part
17	Back panel, blue	1	6	Provides grip to back of gun, aesthetic	Plastic	Injection Molded
18	"Custom screw, 1/2" len, 1/8" dia, flat head"	1	<1	Supports back panel	Stainless Steel	Std Purchase Part
19	Rubber o-ring for Part #18	1	<1	Seals screw, provides snug fit	Rubber	Std Purchase Part
20	"O-ring, rubber, red 1/4" dia"	12	<1	Seals valve assy	Rubber	Std Purchase Part
21	Clear plastic spring cap	12	<1	Caps spring (Part #22)	Plastic
22	"Small spring, 1/2" len"	12	<1	Translates input to opening valve, reset valv when released	Stainless Steel	Std Purchase Part
23	"O-ring, rubber, red, 1/8" dia"	12	<1	Seals (Part #24) to valve assy	Rubber	Std Purchase Part
24	Pin	12	<1	Holds valve in place, allows for vertical motion	Stainless Steel	Std Purchase Part
25	Plastic valve	12	<1	Glued to pin, opens/closes each syrup line	Plastic	Injection Molded
26	Soda gun Nozzle, plastic, blue	1	13	Focuses final soda dispense	Plastic	Injection Molded
27	"Black, O-ring, rubber, 1" dia"	1	<1	Seals nozzle head to gun	Rubber	Std Purchase Part
28	Soda gun body	1	113	Directs and organizes flow for all fluids exiting soda gun	Plastic	Machined in five layers, irreversibly sealed together, post-drilled
29	Soda gun nozzle base	1	10	Creates central location for syrup+soda to mix and exit gun	Plastic	Turned, glued to soda gun body
30	Soda gun nozzle base retaining pins	2	<1	Create fixture points for nozzle base	Stainless Steel	Turned
31	Stickers (misc.)	12	<1	Provides information and instructions about product, barcodes, safety information use, and beverage types	Paper	Printed
Flow Regulator Sub-Assembly
32	Plastic Regulator Backing	1	41	Hold tubes to regulator	Plastic	Injection Molded
33	"flat top, 3/4" len, 1/4" dia, philips head screw"	4	3 (ea)	Fastens regulator casing together	Stainless Steel	Std Purchase Part
34	Tube retainer, retaining clips	20	<1	Retain the tube retainers to base	Stainless Steel	Std Purchase Part
35	Tube housing, main body	1	46	Holds the tube housing	Plastic	Injection Molded
36	Tube housing, single holder	10	6	Connects two sides of tubes	Plastic	Injection Molded
37	Shut-off screw	10	<1	Shuts off soda flow	Plastic	Injection Molded
38	"Shut-off screw o-ring 1/4" dia, rubber"	10	<1	Seals shut-off screws	Rubber	Std. Purchase Part
39	Flow adjustment screw	10	<1	Adjusts syrup/water ratio	Plastic	Injection Molded
40	"Flow adjustment screw o-ring, 1/4" dia, rubber"	10	<1	Seals adjustment screw	Rubber	Std. Purchase Part
41	"Housing retaining pin 1", 5/32" dia"	2	4	Holds tube housing halves together	Stainless Steel	Cut to length
42	Pivot pin for separating mechanism	1	<1	Creates pivot point for half separator of plastic reg. housing	Stainless Steel	Cut to length
43	Plastic regulator fronting	1	63	Hold tubes to regulator	Plastic	Injection Molded
44	Cap of separating mechanism, white	1	<1	User interaction point for separator mechanism	Plastic	Injection Molded
45	Cap of separating mechanism pivot	1	<1	Held cap to main separating body	Stainless Steel	Turned/Lathed
46	Main separator body	1	5	Separates the halves	Plastic	Injection Molded
Small Tube Sub-Assembly
47	Small Eaton Synflex Tubing (4203-0400)	10	11	Carries syrup to gun	Plastic	Std. Purchase Part
48	Plastic Hose Clamping Ring (orange)	10	<1	Connects syrup tubing to end cap	Plastic	Injection Molded
49	Ridged End-Cap	10	<1	Connects tubing to dispensing system	Plastic	Injection Molded
50	"O-ring, rubber, 3/8" dia, black"	10	<1	Seals end cap	Rubber	Std. Purchase Part
51	Plastic, anti-friction ring	1	1	Prevents metal casing from cutting tubing	Plastic	Injection Molded
52	Outer tubing casing, metal	1	200	Gathers all tubes, protects against wear, allows for flexible movement	Stainless Steel	Std. Purchase Part
53	Soda gun base connector	1	11	Connects handheld gun to the tubing casing	Plastic	Injection Molded
54	Tubing holding plate	1	10	Holds all tubes in correct positions for handheld gun	Stainless Steel	Cut, stamped
Large Tube Sub-Assembly
55	Rev-Flex P-E Hose	10	63	Carries liquid from source to soda gun assembly	Plastic	Std. Purchase Part
56	Hose clamp	10	2	Fastens metal hose cap to hose	Stainless Steel	Std. Purchase Part
57	O-ring, rubber, black	10	<1	Seals threaded hose cap to assembly	Rubber	Std. Purchase Part
58	Hose cap, metal	10	7	Allows liquid to flow from one tubing to another	Stainless Steel	Machined

Design for Manufacturing and Assembly [DFMA]

To observe areas of simplification and improvement for the system, a manufacturing and assembly analysis was run to look at ways to optimize the system for simplicity, ease of manufacture, and component minimization. While part minimization is limited by the number of soda types that can flow through the gun and their respective repeating subassemblies, the designs were not close to being fully optimal.

Manufacturing

Guideline	Good Design Choices	Areas for Improvement
Minimize Part Count: Eliminate fasteners, part consolidation	Soda gun main body is one complex part	Eliminate regulator tube retaining clips (24 ct) and replace with snap-in geometry Replace screws in flow regulator with snap-fits Combine design of shut-off and flow adjustment valves Combine soda gun butterfly clips
Standardize Components: Take advantage of economies of scale and known component properties	O-rings were very standardized Small parts all repeated at least 10 times Standard materials (all either plastic or stainless steel)	Make screws standard size and length for repeatability Eliminate custom parts like small screw with o-ring in gun front panel
Commonize Product Line: Economies of scale, minimum training and equipment	Plastic parts are injection molded, a low-labor cost but high tooling cost process	Standardize custom-made components to reduce number of dies needed
Standardize Design Features: Common dimensions for fewer tools and machine set-ups	O-rings and screws were standard sizes and repeated often Custom parts were all in the same size scale, and could easily be made on small injection machines Single soda subsystem was exactly repeated 10 times for standardizing	Eliminate hex screws Simplify soda gun body to not require CNC machining
Keep Designs Simple: Simplest way to achieve needed functionality	Press valves for soda release Water pressure from tap for power of system O-rings easily replaceable, and good simple seal	Eliminate complicated regulator and replace with valve by-pass on each tube Simplify soda gun body
Multifunctional Parts: simplifies by letting one component serve many functions	Flow regulator consolidates hoses, regulates flow and allows user input Soda gun dispenses all soda without cross-contamination All parts are non-corrosive	Shut-off valves in regulator could be combined with adjustment valves
Ease of fabrication: Choose materials easy to work with	All materials are plastic or stainless steel	Soda gun body was acrylic and machined in five layers, and could be made from a more easily machinable material
Avoid tight tolerances: because they cause cost and machining time to increase drastically	O-rings eliminate the need for the tight tolerances desired for fluid sealing	None
Minimize secondary or finishing operations:	Most parts loosely fit with seals	Soda gun body requires the most machining, and post-assembly drilling
Take advantage of special process properties: like coloring plastic	Gun is clear, and blockages or cracks are easily visible Buttons are dyed to label what Pepsi product comes out Tubes are clear but for club soda and water	Color-code tubes to make it easy to determine which tubes line up in the three-part system

Assembly

Guideline	Good Design Choices	Areas for Improvement
Minimize Assembly Surfaces: and sequence them	Clear assembly surfaces for soda gun panels	Eliminate regulator
Use subassemblies: can be tested and assembled separately, or outsourced	Single syrup flow assembly repeated for every soda (10 times) Standard materials (all either plastic or stainless steel)	Eliminate regulator as an extraneous consolidation method
Mistake-proof: unambiguous, unique assembly orientation	None	Soda tubing is not labeled at all except for a single removable sticker Ambiguous flow order Buttons on soda gun not associated with relevant tubes Unintuitive part assembly for regulator valves Ambiguous order for button valve assembly
Minimize fasteners: snap fits and part consolidation	None	Eliminate hex screws Eliminate regulator to replace with by-pass valves on each tube Replace threaded insert/screw combinations with single screw
Minimize handling: position for insertion or joining is easy to achieve	All removal screws accessible	Assembly requires inserting components from all directions
Minimize assembly direction: ideal is to add each component from top to base	Clear order of operations for assembly and disassembly	None
Provide unobstructed access consider assembly path	None	Soda gun body impossible to reversibly disassemble Many levels of assembly required for maintenance
Maximize assembly compliance:' chamfers and radii help assemble parts with variance	Seats for tube regulator parts were chamfered to aid in tube insertion Seats slid into their respective locations and required no fasteners	None
Minimize extraneousness: features that have no functional use but aid with assembly	None	None

Failure Mode and Effect Analysis [FMEA]

We performed a Failure Mode and Effect Analysis on the soda gun. We considered individual parts, sub assemblies, and user interaction when conducting this analysis. The primary focus of this analysis is to identify the cause and effect of potential failure modes in our system. We began by gathering a list of parts and sub assemblies and different failure modes for each part. We then discussed the effects of each failure, the causes of each failure, and any design controls implemented to the part (if any). We scored the severity of failure (S), probability the failure occurs (P), and ease of detection (D) on a scale from 1-10 to determine an ultimate risk priority number (RPN). Parts with higher RPN are of highest priority when considering a redesign for a safer system.

Item and Function	Failure Mode	Effects of Failure	S	Causes of Failure	O	Design Controls	D	RPN	Recommended Actions
O-Ring: Seals tubing and valves	Break or Snap off	loss of fluid control	4	stress/ fatigue in material	2	Indention in tubing or valve where each o-ring is placed	4	32	Thicker o-ring
O-Ring: Seals tubing and valves	not sealing properly	fluid leakage	4	material overstretched	1	Indention in tubing or valve where each o-ring is placed	5	20	more flexible o-ring
Soda Button Valve: open/close to release/prevent fluid	not fully opening	loss of soda output	4	valve not properly aligned	5	spring and butterfly clips align valves	3	60	tighter tolerances to maintain alignment
Soda Button Valve: open/close to release/prevent fluid	not fully closing	endless soda output/ leakage	4	valve not properly aligned	5	spring and butterfly clips align valves	3	60	tighter tolerances to maintain alignment
Soda Tubing: pathway for fluid to flow from its original container into the soda gun	puncturing/ kinking	leaking	4	ends of tubing catch on metal connectors	4	metal casing gathers individual tubes	2	32	plastic buffers between metal connectors and tubing, rounded edges on connectors
Soda Tubing: pathway for fluid to flow from its original container into the soda gun	puncturing/ kinking	incorrect soda ratios	2	ends of tubing catch on metal connectors	3	metal casing gathers individual tubes	3	18	plastic buffers between metal connectors and tubing, rounded edges on connectors
Soda button spring: stores mechanical energy when valve is pressed, allowing valve to open and close easily	sticks and doesn't properly compress	valves and buttons would not work	3	fluid debris build up around spring	1	none	6	9	ensure spring is anti-corrosive
Tightening Screws: adjust syrup ratio allowed into soda gun system	over/ under tightened	incorrect syrup ratio	2	user misjudges amount of rotations needed to provide correct flow rate	3	none	3	18	provide some guidelines that help the user identify how many rotations signify the correct flow rate
Tightening Screws: adjust syrup ratio allowed into soda gun system	stripped screw head	loss of flow control	4	user applies too much pressure to screw head	2	none	2	16	consider re-selecting a stronger material less prone to stripping
Tube clamps: fasten tubes to soda gun	clamps fall off	loss of flow control	2	contact stress concentration on clamping	2	none	4	16	redesign clamps for higher factor of safety
Nozzle: consolidates flow and directs it into drinking cup	fatigue, cracking	soda leaks and sprays in unwanted direction	3	too high of fluid pressure	2	none	1	6	use a stronger plastic to better resist fatigue
Nozzle: consolidates flow and directs it into drinking cup	fatigue, cracking	soda leaks and sprays in unwanted direction	3	user misuses, drops soda gun onto nozzle	3	none	1	9	use a stronger plastic to better resist fatigue
Plastic Buttons: designate soda type and release valves	fatigue, overuse	loss of selection modes	3	contact stress from overuse or user misuse	3	none	1	9	design stronger connection for buttons to resist early fatigue
Soda gun: Directs and organizes flow for all fluids exiting soda gun	clogging from syrup build up	product (at least one soda line) becomes nonfunctional	5	not properly cleaned/maintained	3	none	1	15	implement cleaning feature to clear out all fluid lines
Soda gun: Directs and organizes flow for all fluids exiting soda gun	fatigue, cracking	product (at least one soda line) becomes nonfunctional	5	user misuse, dropping or slamming product	3	none	1	15	design soda gun with a higher factor of safety to resist early fatigue
Butterfly clips: align valves and provide normal force when button is pressed	jam or stick	valves don't work properly, potentially releasing multiple soda syrups	2	contact stress knocks clips out of place	3	pocket cut in soda gun body for clip placement	5	30	fasten butterfly clips down with screw or adhesive
Regulator housing: gathers, labels, and aligns soda syrup tubes	fatigue, cracking	tubes not consolidated	1	contact stress on part	2	none	1	4	redesign housing to resist early fatigue, consider stronger plastic
Regulator housing: gathers, labels, and aligns soda syrup tubes	syrup label sticker falls off	loss of syrup organization; can't tell which tube holds which syrup	2	liquid spills on label, causing adhesive to wear	2	none	1	4	eliminate sticker all together and implement better labeling system

Design for Environment [DFE]

We found that the soda gun is optimized for multiple users to deliver a variety of soda drinks from the same location. In terms of functional optimizations, the soda gun could be made more ergonomic and more easily cleaned. These changes could improve the life of the gun and its ease of use. Individual parts can be optimized to take into account the degradable nature of the materials used, but the added cost of different materials could make environmentally friendly materials less practical to use or even more wasteful. Further, the packaging of the gun could be optimized to reduce waste and save on transportation costs. Seeing as the gun is usually bought in combination with other equipment, the total packaging and transportation costs would need to be examined for the purchased assembly as a whole. Finally, the parts can be made easily replaceable (especially the O-rings) which would prolong the life of the soda gun and cause less waste by allowing the gun to be reused instead of thrown away. This can be done by standardizing the part, making the gun easy to take apart with only simple tools, and providing consumers with easy-to-follow electronically-delivered repairing instructions.

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EIOLCA - Economic input-output life cycle assessment

In this section, we are studying the environmental impact of a whole soda dispensing system, considering the emission of greenhouse gases in the form of equivalent millions of tons of CO2 (mtCO2e). We will use the model from eiolca.net . The US 2002 Purchaser database has been used and the prices entered accordingly.

	Production	Use
Item purchased	Soda Gun System	Tap Water	Syrups	Electricity	CO2
(a) Picture	Source : wunderbar.com	Source : waterpurifier.org	Source : amazon.com	Source : green-lantern-electric.com	Source : micromatic.com
(b) Economic Sector # and Name	333319 : Other Commercial and Service Industry Machinery Manufacturing	483000 : Water transportation	311930 : Flavoring syrup and concentrate manufacturing	221100 : Power generation and supply	325120 : Industrial gas manufacturing
(c) Reference Unit	1 system	1 gal	1 gal	1 kWh	1 20lb tank of CO2
(d) Units Consumed per Product Life	1	x	1/5 *x	y	z
(e) Cost per Unit ($ 2002)	$ 4000 now ?	$ 0.002 in 2013 -> $ 0.00154 in 2002	$ 13 in 2013 -> $ 10 in 2002	$ 0.15 in 2013 -> $ 0.12 in 2002	$ 20 in 2013 -> $ 15.44 in 2002
(f) Lifetime Cost = (d)*(e) ($ 2002)
(g) Economy-wide mtCO2e released per $1M of output for sector (b)
(h) Implied mtCO2e released per Product Life = (g)*(f)/$1M	Text here	Text here	Text here	Text here	Text here
(i) CO2 Tax @ $30/mtCO2e = $30*(h)	Text here	$	$	$	$
(j) Assumptions		360 cups per day = 22.5 gallons per day	1:5 mix with water		1000L of soda per tank

Team Members

Elle Allen: DFMA Lead

Julien Locher

Taryn Monteleone: DFE Lead

Dan Murby

Christy St. John