Gate 4 - Group 15 - 2012
(→Difficulty Rating Scale)
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Revision as of 00:53, 27 November 2012
The purpose of the fourth gate was gain a better understanding for how the device used its parts to generate motion and to create design changes for the circular saw on a system level. To accomplish this, a complete reassembly of our product was done and each step was recorded in detail to be used in later analysis. This was crucial because it helped to gain an understanding in how each of the parts were assembled in accordance to the kind of motion they would be responsible for producing. In addition, this was also important when considering design revisions because they would ultimately impact the assembly process of the product.
Project Management: Coordination Review
Cause for Corrective Action
Product Archaeology: Product Explanation
In order to assemble the product, the following tools are needed;
- T20 Torx Screwdriver
- 13 mm Torque Wrench
Product Assembly Guide
Ease of Reassembly
Difficulty Rating Scale
The difficulty scale for the product assembly is based on three different ratings. Each rating is based on a numerical scale ranging from one to three. A rating of one would be described as easy, a rating of two would be described as medium, and a rating of three would be described as hard. Each rating takes into consideration the simplicity and amount of knowledge required in order to perform each step. Simpler tasks require less effort or technical knowledge while higher rated tasks may require advanced knowledge of the product or special tools at the user's disposal.
|1||Requires little to no effort or knowledge prior to assembly (ex. removing screws or tightening something with a wrench). Step is performed in a relatively quick amount of time.|
|2||Requires greater force to perform assembly step. May require stabilization of product (ex. multiple hands holding product or vice grip) or knowledge of product prior to assembly. Step may take some time to accomplish, but does not cause a serious interruption in the assembly process.|
|3||Requires extreme force or tool not necessarily available to average person to perform assembly step (ex. force fitting using a machine). Certainly requires knowledge of product's design and intended functions of parts. Difficulty may cause assembly step to be incapable of performing until proper tools or knowledge are acquired.|
Figure _. Table of difficulty ratings
Difficulty of Steps
|Step #||Difficulty Level||Assembly Method||Reasoning||Evidence|
Figure _. Difficulty rating of assembly steps
Figure _. Step by step assembly guide
Total Assembly Time: _ hour and _ minutes
Product Assembly Challenges
Another design consideration that could affect serviceability of the circular saw is the inclusion of an extendable handle. The current model restricts the user to only being able to use the product within reach of their arms and an extendable handle could work around this issue by increasing the distance in which the user could operate the product at. This design revision would require a complete change in how the handle is attached to the housing of the saw in addition to how the main power cords would be connected from the trigger to the motor. The handle would be attached to the housing by a collapsible frame which may be drawn in or out and then locked in at the appropriate distance by the user. The distance at which the handle may be drawn would not be extremely long because that would greatly decrease the overall safety of the product’s usage because they would be offered less control. In addition, a handle that is too long would also result in greater stress on the materials in the handle by increasing the length of the moment arm that holds the saw. In order to accompany the change in the design of the handle, the manufacturing process of the saw will also need to change. The handle would still be manufactured using injection molding and the collapsible shaft that connects it to the housing would most likely be created using die casting. During assembly, the shaft would probably be connected in between the handle and the motor housing by use of joints. The joints would either be unrestricted in one plane of motion or be given the ability to be locked in place so that the user can choose how they prefer the product to behave as they maneuver it forwards and backwards.
The extendable handle increases the serviceability of the product by enabling the user to operate it at a greater range. This can be useful if the product is being used to cut a very large surface or if the product needs to be maneuvered in an area where the user doesn’t have direct access to. This can also be a beneficial for the user because it will prevent them from having to bend over while trying to cut the material over a long distance; instead they will be able to maintain their original posture and simply push the circular saw in the direction that they want to be cut which can help reduce the risk of accidents happening. The design revision also changes how the user can interact with their working environment by allowing them to access hard to reach places and still be able to cut material safely. This revision may be expensive on the levels of production and sales, but the user may find this feature particularly useful if they find themselves needing to cut large or out of reach objects easily.
A design consideration that would greatly increase the convenience of the circular saw for its user would be the inclusion of a way for sawdust and debris to be collected. During the use of the product, waste material is often blown off to the side of the working environment and is left to be cleaned up by the user after they are done. In order to work around this issue, a proposed design revision is to include a detachable vacuum hose that may be mounted to the end of upper blade guard closest to the user. As the saw blade cuts through material, the dust and debris created that exits the end of the upper blade guard would be fed into the hose and be collected in an external container such as a reusable bag for later disposal. In order for the current model of the product to accept this design change, a hole would need to be created in the upper blade guard and a small extension would need to be made on the exterior of the upper blade guard where the hole is so that the hose would be attached to or inserted into it. This creation of the extension would result in revising the manufacturing process so that the mold used to create the guard would feature it during the casting process and the hole would need to be machined out using a tap and drill.
The dust vacuum would change the way that the user operates the product within their working environment by now requiring less consideration for clean up after the product’s usage. Prior the design revision, the user would need to decide if their environment would be suitable to generate waste in. The addition of the dust vacuum ensures that little no waste is generated, and so this consideration for the operating environment is reduced through this function. Economically, this addition will cost more to produce in the manufacturing process because more material will be used and the molds used for manufacturing the parts will be revised. In addition, the inclusion of an exterior power source and mechanism that drives the vacuum will cause the price of this extension to increase as well. In order to give the user more options, it would be recommended that this revision be made such that the user has the option to choose whether or not they want to buy it. If not, a plug will also need to be produced in order to fill in the hole that is made for the vacuum tube. Though this revision will increase the price of the product, the average customer might find this function beneficial if it means that they have less material to clean up after using the circular saw.