Morehead state university

Homework 4

615 Advanced CADD – Dr. Madhavannair

Travis Fisher

10/9/2012

1. A brand of Terminux® leather belts are sold at a rate of 58,321 units per year. Assuming that Terminux ® sells it through a single distributor that accounts for 23.25% sales in that category,

what should be the quantity of product sold? Assume that the data from a concept test with industry managers responsible for purchasing leather belts indicate a definitely-would-buy

fraction of 0.3125 and probably-would-by fraction of 0.1815. Use a value of 0.38 for Cdefinitely and 0.18 for Cprobably.

Q = N x A x P•Q= sales (annual)

•N= number of (annual) purchases

•A= awareness x availability (fractions)

•P= probability of purchase (surveyed)

= Cdefx Fdef+ Cprobx Fprob

2. Take the design you selected from HW 2.

Office Chair(a) Mention the material used for each part.

1.high density foam with quality mesh/fabric /leather/ pu - Bicast leather is a split leather with a layer of polyurethane applied to the surface and then embossed. Bycast was originally made for the shoe industry

for glossy shoes, and recently was adopted by the furniture industry. The resulting product has an artificially consistent texture that is easier to clean and maintain. (wikipedia, 2012)

2. ABS plastic frame

3.aluminum alloy base - Unalloyed aluminum is ductile, exhibits moderate strength, and is very resistant to corrosion under most circumstances. Aluminum can be dramatically strengthened by the addition of

appropriate alloying elements (Cu, Mg, Mn, Si, etc.) and subsequent heat/work treatments. Aluminum is commonly used in both wrought and cast forms. (MatWeb, 2012)

3.wood seat base

4.) Alluminum Alloy for the wheel pins and adjustable handles

5. base : ABS nylon blend - Blends of nylon 6 with four acrylonitrile–butadiene–styrene (ABS) materials were investigated over a range of compositions using an imidized acrylic (IA) polymer as the

compatibilizing agent. In general, incorporation of the IA polymer can lead to super tough blends using a broad range of ABS materials. Increasing the ratio of nylon 6 to ABS improved the modulus and yield

strength and did not significantly affect the room temperature impact strength up to a certain level. (MatWeb, 2012)

(b)How would you manufacture each component of that design? / (c) Mention the manufacturing processes that you would use for all the parts.

1.) The foam will be cut to specs on a stamping press with a die cutter. 2.) Plastic frame will be die casted with by injection molding.

3.) Aluminum alloy base will be machined with a CNC.4.) The seat platform will be wood that can be cut to specs using a band saw. The wood is cheaper than using plastic and it also provides the strength and elasticity that is necessary for supporting a person’s

weight. 5.) Base and frame would be casted through the process of injection molding.

(d) Then mention the assembly processes involved with the sequence.

The proper selection of assembly process is critical, as it influences the production rate, quality, and cost of the product through tradeoffs in productivity of the facility and workers. (Assembly Processes, 2012) This product will be bought by the customer disassembled and in a box and there will be a self-assembly

process involved. Ready-to-assemble furniture is typically packaged in a kit form with the pieces packaged in one or multiple boxes. The kit may contain a number of flat parts, fasteners, screws, fixings, and other parts that are needed to assemble the furniture. Merchants benefit from selling ready-to-assemble furniture because furniture that is already assembled tends to be bulky and more expensive to store and to deliver. Since the furniture does not need to be assembled in the factory, ready-to-assemble furniture is also less expensive for the merchant to purchase. Due to these many factors, selling flat pack furniture is a more cost effective method of conducting business.

(e) Now, looking back at your initial design, would you make some changes to it? After looking back to the initial design I have decided to keep everything the same. The concept

screening and scoring tables clearly showed the advantages of the office chair that I have chosen. This does not mean that there is no room for improvement or future work this just means that the product

concept is ready to develop right now. Updates can be made to future models of the product, but the main goal is to get a desirable and functional product design and start developing ASAP.

(f) Is your design efficient in terms of design for assembly- Yes this product is designed so that it is simple enough for the customer to assemble alone with a few basic tools. Also it comes with a step by

step assembly guide. design for disassembly- Yes this product should be even easier to disassemble than it is to assemble,

atleast that is usually the case. Again this will only require basic tools e.g. Phillips or flathead screwdriver.

design for service- This chair is designed to succumb to more than its expected abuse, but in the case a part needs replaced or repaired since the assembly and disassembly is so simple this should be no

problem at all. Also the PU leather is better than genuine leather in this case because it is easier to clean and maintain (service).

design for environment- Yes all of the materials used are either reusable or renewable. design for manufacturing- This is a pretty straightforward product. The chair has been around for

thousands of years, this is just a modern version. With that said there is no question that this is designed for manufacturing. All of the process presented in section b/c can be done in house and shipped out as a

final product from the factory.

(g) Include a hand drawn sketch of the design from HW 2

(h) Include a modified sketch for the design based on changes made to it based on the above principles.

Like I said earlier, this design is still the same that it was after passing through the concept screening and scoring tables. So the modifications made for this product will be changes and improvements made to

update this model in the future. One thing I would like to emphasize on about the possible modifications made is how the back piece is significantly more curved than the first design. Not only will this added a

desired comfort for the customer throughout the day by contouring to the lower back but believe it or not it will actually contribute to the flexibility of the back piece. This means that the person sitting in the

chair can lean backwards without worrying about whether or not the chair will break.

(Ahrend Office Chair, 2012)

If you notice above this design allows for flexibility of motion back in two directions, forwards and backwards. So along with the added comfort, the flexibility also means a higher modulus of elasticity and

on top of that it adds a significant level of convenience for the user because this means they can relax back for a moment and lean forward again, all without even adjusting any settings.

BibliographyAhrend Office Chair. (2012). Retrieved from http://www.mnzl.nl/my-3d-work/ahrend-250-office-chair/

Assembly Processes. (2012). Retrieved from http://www.amazon.com/Assembly-Processes-Automation-Manufacturing-Engineering/dp/0849355656

MatWeb. (2012). Retrieved from http://www.sciencedirect.com/science/article/pii/S0032386199001056

wikipedia. (2012). Retrieved from http://en.wikipedia.org/wiki/Bicast_leather