Gate1: Product Planning
Product Management: Request for Proposal
Just as many companies and researchers in the world will reverse engineer a product to replicate or improve upon it, we will be using these same techniques to look at our product on a much closer level to completely understand the intricate workings of the Black and Decker jigsaw inside and out. Through this in depth examination, we plan on learning how electricity is introduced to the saw and how the electrical energy is eventually converted into translational mechanical energy. We will also be looking at every component individually, and taking note on the reasoning behind each component and why the engineers ultimately chose that component over other possibilities. Along with this, we will be considering possible improvements to this product in all aspects.
We will start this process by first looking into what tools will be needed for disassembling this device. After inspection we believe we will need but are not limited to the following tools depicted in Figure 1.
|Phillips and Slotted (Flat-head) Screwdrivers|
|Torques Headed Screwdrivers|
|Channel Lock Pliers|
|Snap Ring Pliers|
|Sockets and Ratchets|
Table 1 Tools list
The tools listed have been determined from looking at the product and from anticipating possible needs once the product is split open. After taking some time examining the jigsaw, we determined that the first thing to be removed is the base plate, by removing the two screws holding it in place. Once that is removed, the saw should be ready for the body to be split. This is done by removing the 10 screws from the right side that is securing the two half’s together. Once the body is separated, the internal components should be ready to start disassembling.
If able, the head (linear actuator) will be removed first. Any linkages will be disconnected and screws or bolts will be removed. The gear train will be pulled next by removing any set screws or securing brackets that may be holding it in place. Once the gear train is out, we can remove the motor along with the cooling fan. The wires will be disconnected and any clamps or screws holding it will be removed. That should be the major components of the saw.
Once all of these components are removed, they will each be broken down and disassembled to their simplest state or until they can be disassembled no further without destroying the component, such as crimped end plates, etc. The assembly of this device will be conducted in the reverse order of the disassembly. Unlike a more complex unit, such as an Internal Combustion (IC) Engine, there will not be any need for extra steps when reassembling the product. In an engine, there are tolerances to be checked in all of the bearings and valves, as well as special instructions for gaskets and gasket sealer. In the case of this Jigsaw, due to its simplicity, there is no need for that much involvement while re-assembling. The components will be reinserted opposite of removal, reconnected, and secured. Once these are all back in place, the two half’s of the body will be joined and re-secured with the screws primarily removed. It should now be ready to plug in and be tested for operation.
After taking time to examine the product, it appears to be fairly straight forward as far as the complexity of the saw is concerned. The estimated time for complete disassembly including each component is approximately two to three hours. With the mechanical background of certain team members, this reverse engineering task does not appear to be too challenging. However, not every team member is familiar with disassembling a product to examine and/or make repair’s, so for these members, it will be a new learning experience to understand the full functionality of a device and all the different systems that combine to give the final outcome, which in this case is a linear actuating saw blade. Because of this inexperience within the group, these members will need to be more involved with the disassembly of the saw to gain some experience and to learn how components are assembled, while the members with more experience will assist and explain any questions that may arise during the disassembly.
All members will be involved with tearing down the product, it is just more beneficial for those less practiced in this type of action to have the opportunity for a hands on experience. The group as whole, even with the inexperience of some members, feels the disassembly of the saw should not be overbearing with its complexity and each member is confident in there abilities to be able to tear this product down to its simplest state and then return the product back to its original state in a working condition. There are a few challenges that have been discussed, such as plastic clips or snaps within the device that help hold the body or components in place. From experience, these snaps tend to break very easily even when being cautious. While this may not be completely avoidable, there will be the utmost attention paid to the disassembly of the saw to avoid breaking any possible securing devices.
Also, another challenge that was discussed was the possibility of a component coming apart during removal or disassembly and not allowing the members to know how this component reassembles correctly, such as a spring coming out that was under compression. To alleviate this problem, the members will be cautious to examine each competent before removal, note how the parts are assembled, and carefully remove and secure the parts accordingly.
Lastly, concerns of wires within the saw were discussed. There is a variable speed setting on the side of the saw that gives the user the capability of cutting different materials. It may be the case that the wires for this selector are soldered to another component instead of the wires utilizing quick disconnects. This may then give trouble in the dis-assembly of the saw if it does not allow the half’s of the unit to separate or it limits the saw to be broken down any further. This will most likely not be the case, but if it is encountered, then the wires will have to be unsoldered, or cut in the case that the solder points cannot be reached. This will not inhibit the saw from working again because the wires can be spliced back together during reassembly.
Capabilities and Shortcomings
Our group has a wide range of capabilities and shortcomings that will aid us and challenge us with respect to this project.Table 2 outlines these qualities.
|Team Members||Capabilities||Shortcomings||Skills Development|
Table 2 Group Capabilities
We have a set meeting time every Monday and Thursday from 5:00 pm to 7:00 pm; weather we stay for the whole period or go over depends on the amount of work we have left to do or have already completed. This way we will be able to assess what we have to do at the beginning of the week, and we can focus our goals for the weekend. Along with these meetings we will be able to check in with each other after class ends at 5 on Wednesday, and Friday. This set up allows us at least 8 hours of group work in between gates, if there are only two weeks in between gates. In addition into the work that will be completed during our group meetings, we will each be contributing at least three hours of individual work that will be assigned to us during our meetings. For our meeting places; The first meeting proceeding gate submission will be held in a library, where we will be outlining what needs to be done in following meetings and discussing everyone’s role for the new gate. The second meeting will be held in the lab for product handling, and the rest of the meetings will be held either in the library or in the lab, depending on what needs to get done. Everyone is expected to attend, unless they have provided a valid reason for being unable to attend the group meeting. If any decisions are made and finalized during a group meeting, there must be at least three of the members present, and the other member should be notified instantly after the decision has been finalized, to enable the group to be fully informed at all times during the project. Figure 3 provides a detailed explanation of the role and responsibilities expected from each group member.
|Brian Bergh||Project Manager||
|Ariel Regnier||Communication Liasion||
|Travis Burt||Technical Expert||
|Colin Lawson||Computer Expert||
Table 3 Roles and Responsibility
Group conflict will be resolved by addressing the problem in person. If there are issues in between to individual group members, then they should try to resolve their issues on their own. If someone is unhappy or has problems concerning the group, then they will be addressed at the next group meeting. If issues remain unresolved, the teacher will be notified and problems will be resolved from there.
The Black and Decker Variable Speed Orbital Jigsaw JS660 was designed in 2010 with the intention of providing an easy to use and cost effective product that was able to adjust its performance to different cutting materials according to the consumers preference. This was an improvement from the previous 2009 model, the JS515 model, which had no additional blade settings, and therefore was able to appeal to a larger range of consumers, since it could perform a wider range of functions. The decreased price and the ease of use of the product, due to the application of plastic throughout the device enabling a decrease in cost and weight, also appeals to a wide range of consumers, particularly among the middle class. The implementation of the “Smart Select” dial, variable speed switch, and saw blade locking lever enables a considerable amount of ease of use for the everyday consumer as well. The JS660 Jigsaw is listed at a modest retail price of approximately $50, which compared to other jigsaws of equivalent capability is at minimum $10 cheaper.
The tool was intended to be sold and distributed in industrialized countries worldwide. Although the power cord has a 3 conductor head, which is primarily used in North America; with a simple adaptors kit, this tool can be used in any country. In addition, the visual depictions within the “Smart Select” dial help to avoid issues resulting from a language barrier. The economic concerns at the time of development were in developing a cheap and affordable power tool. As previously discussed, this was addressed by using plastic for the outer body of the jigsaw, rather than metal which would result in a higher cost of production. Global concerns have also been previously discussed; the smart select dial settings are depicted through visuals rather than through words to avoid the language barrier of different regions, and although the power cord is manufactured for a specific region, it is easily altered to appeal to a wider audience. These product specifications detail that the Black and Decker Variable Speed Orbital Jigsaw JS660 incorporated a variety of global and economic concerns within its design.
The intended use of this product is to be able to saw through a variety of materials for construction purposes in a quick and easy manner. It can be used in either a home or professional setting, although this tool is typically used in a home setting. The simplicity of the product allows for an ease of use by anybody who has simple, do-it-yourself construction jobs around the house, without the hassle of a large, heavy duty machine. Also, the product can be packed up neatly and tucked away, which is appealing to a homeowner who most likely is not constantly using the product. Along with this, there is minimal maitenence required of the tool, making it very simple for home owners to use the tool at their own leisure without the complications of servicing it. The light weight and small size of the saw makes it easy to transport, which is appealing in the professional field, and the minimal maintenance makes it a convenient tool. This product is designed to easily cut through different materials to any shape or size, and in any pattern; it can cut straight or at an angle as well. This allows the tool to perform a wide variety of tasks, making it a very useful tool when working on a project.
There are four types of energy used in the product. The types of energy are: electrical energy, rotational mechanical energy, pneumatic, and linear mechanical energy. The electrical energy is brought into the system by the cord. The electrical energy is then converted into rotational mechanical energy by the motor. A gear train then reduces the rpm of the motor, which thus increases the torque. Finally, a cam converts the rotational mechanical energy into oscillating, linear mechanical energy. Also, due to friction, a portion of thermal energy is generated throughout the process. To prevent the thermal energy from building up in the product, a cooling fan is present. The fan receives electrical energy from the cord and converts it into rotational mechanical energy. The fan transfers this energy to the air, which is pneumatic energy, moving it out of the saw. Figure 3 provides a visual representation of the energy flow throughout the jigsaw.
The Jig Saw itself is a simple product, and it is make up of a combination of components. The complexity of the components is represented in parenthesis next to the components and is based on a scale from 1 - 5; 1 being very simple and 5 being very complicated. This scale takes into consideration the geometric shape, the manufacturing process, and the physical tasks that the component is expected to perform. The main components are:
- Motor (3)- A simple electric motor made up of copper winding and a magnet to convert the electrical energy to mechanical energy.
- Gears in the gear train (2)- Though the manufacturing process can be rather simple for creating a gear, the most common way being Hobbing, the geometric shape of a gear cause it to be slightly more complex.
- Saw head/actuator (2), which consists of
- Shaft(2)- This includes the CAM and the piston and the air valve.
- Blade guard (1)- Simply two bent steal rods
- Blade support (1)
- Blade (1)- a piece of steal with sharpened teeth cut into it.
- Body of the saw (1), which includes
- Screws and bolts (1)
- Casing (1)
- Plastic dial (1)
- Base plate (1)
- Chord (1)
The most complex interactions among these components would be the gear train, which we are assuming to be five or so gears acting simultaneously intermittently to transfer energy from one point to another, and the translational movement of the saw head shaft. Other interactions include the movement of electrical energy to the motor via the carbon brushes to convert into rotational energy, as well as the rotational energy being transformed into linear oscillating energy via the cam and the reciprocating shaft assembly.
As we examine our product physically, we can see a variety of materials. These materials are listed below.
- Plastic: Within the shell and dials
- Rubber: Present on the handle and the cord, as well as encasing the smart select dial
- Steel: Used for the base plate and the screws/bolts. It is also implemented in the blade and the blade guard
- Paper: Present in the label/instructions
- Vinyl: Present in the labels
- paper: The instructions that come along with the product
Along with these materials there are non-visible materials that are present inside the product. These materials are listed below.
- Copper: Inside the Electric Motor
- Brass: Inside the Electric Motor
- steel: Found in the gears, in the reciprocating shaft assembly.
- plastic: smart select dial assembly, base plate assembly, the fan on the shaft assembly, trigger assembly.
- Rubber: covering internal wires.
- Twine: string found on the motor, securing two wires in place.
- Graphite: Carbon Brushes
- Copper: Inside the Electric Motor
- Brass: Inside the Electric Motor
User Interaction Profile
The user directly interacts with the product in a simple manner. The user has to hold on to the handle of the product during use, and has to pull on the trigger while the saw is against some material in order for it to perform its duty. In order for this to happen though, the user must have selected a proper material in regards to the use of the saw; for example the user would not interact with the saw very well if the choice material for cutting is cement, or tree trunks. Once a proper material is selected, the user must set the smart select dial to its proper setting in regards to the material selected. To use the product, the user must plug in the power cord into a wall outlet, orient the base plate of the saw perpendicular to the selected cutting material, firmly grasp the handle on the top of the tool, compress the trigger on the handle of the saw to allow the electrical currents from the power cord to start the energy flow, and apply pressure to the saw to overcome the resistance force of the material. When the blade needs to be replaced, it is a simple process to open the blade lock, Remove the old blade, and replace it with the new one. There is also a convenient compartment located externally on the product to eliminate the hassle of storing the blades in a separate item.
The product has been designed so that it is easy for just about anyone, of any (appropriate) age to use. The ease of the interaction is primarily based on practice with the jigsaw. The more times a consumer is using the jigsaw, the more comfortable they are with maneuvering and controlling the jigsaw, and the easier it is for them to accomplish the desired task. No majorly difficult concepts are introduced while using the saw; many of the actions are equivalent to household tasks, such as a mechanical cake beater, or ironing, or vacuuming. It is fairly easy to use as well; as stated above it is equivalent to many house hold tasks. Since the tool does not weigh much, it does not require a user of above average strength to control it, and when the blade is turned on, after some practice, the method of steering while cutting is a fairly easy task. Though there is some resistance, it is still maneuverable by the average person.
Maintenance is not required on a day to day basis; the blade is made out of steel so it does not dull after one use, there for requiring the user to change the blade infrequently. The exchanging of a blade, As previously stated, is a simple process of releasing the blade lock, removing the old blade, inserting a new blade, and relocking it. The blade needs to be oriented properly so that the teeth of the blade is facing away from the body of the product, so as to allow the cutting process to happen when the product is moving forward through the material. Also there is a small air vent right next to the blade that blows away the material dust as it is being cut, so no cleaning is required.
Product Alternative Profile
|Hand Saw||The origin all saws, there are many types of and saws such as, a crosscutting saw, ripsaw, and hacksaw just to name a few, but they are all utilized in the same way. They are just used for different purposes. ||
|Reciprocating Saw||Like the jig saw in that it linearly actuates a blade but a different design. This saw uses a blade that runs parallel to the length of the device. ||
|Band Saw||Usually a stationary machine. It utilizes a continuous blade that is formed like a belt. They come in two variations, vertical and horizontal. ||
|Band Saw||A smaller stationary machine usually used for small projects. It has a linear actuating blade. ||
|Dremel Trio||A rotary tool much like a small drill. It is set up much like a jigsaw with a base plate. This device has multiple bits for cutting many types of materials. It uses high speeds for making cutting quick and easy. ||
Table 4 Product alternatives
The above table provides a visual representation of the comparisons detailed below.
- Comparing the jigsaw to these alternate products gives the user a further understanding of this product and whether or not this product is the correct choice for the user and its intended use. First looking at the hand saw, there are many downfalls in comparison. The hand saw takes much more energy to use and is more intended for straight cuts from one point to the other. A jigsaw on the other hand can be used with much less effort and is capable of getting into tighter spaces. It also has the ability to cut curved paths or around objects. For most cases, the hand saw is outdated and is used only in certain circumstances.
- The reciprocating saw on the other hand is fairly similar to the jigsaw, but is larger in size. Unlike the jigsaw this is designed for heavier duty use such as in construction. It is used to get things done quickly and effectively. These saws come corded or cordless for easier mobility and are widely used. The real difference between these two is not which one is better, but what is the intended purpose. If cutting through walls and pipes is what the saw will be used for, a reciprocating saw will handle that nicely. On the other hand, if a more meticulous cut is preferred for cutting electrical outlet holes in drywall for example, a jigsaw will meet those criteria much better.
- If portability is not a concern and heavy usage as well as heavy cutting is needed, then a band saw may be a better choice. The band saw comes in very many different sizes to meet the needs of a large demographic. They have bench top sizes through saws as big as a car. For this article, the focus will be on the bench top style due to the fact that this project relates to the average user and not for industrial use. Bench top band saws are very good for cutting many types of materials as long the material can be placed on the saw itself. It provides a very rigid blade and cuts though materials very easily. While many things could be cut with a jig saw, having the blade stationary and moving the material around gives many benefits, such as no vibration and the blade walking creating a non-straight cut. On the other hand, there are many limitations to a band saw because of its size and non-portability. It is usually used for making straight cuts and cannot be used to cut anything that can’t be placed on the machine directly.
- A scroll saw is actually very similar to a jig saw in its operation. Their blade sizes are relatively the same as well as their basic operation. One could argue that the scroll saw is the stationary version of the jigsaw. It is actually a combination of a jig saw and a band saw. These are usually used for hobby purposes, in that they allow shapes to be cut very easily due to there narrow and short width blades, but are very rigid and do not bounce the material around as a cut is being made. They are great for making detailed cuts and do not fatigue the user because the vibration is transferred through the device and not the user. Unlike the jigsaw, this machines downfall is very similar to the band saw in that the material must be placed on the machine where as a jigsaw can be taken to the material and can be used in small spaces as well as any direction.
- The Dremel Trio is a very versatile tool. With all of the different tool bits, it has the ability to do anything from sanding, drilling, and cutting just to name a few. The dremel is small and gives the freedom to make quick cuts, and because it uses rotational bits, it is not limited to any shape that needs to be made. But the jig saw still has its advantages in comparison. The Dremel is very limited with the thickness of materials it can cut through and is very difficult to cut smooth lines. The jig saw has a flat saw blade giving the user much more control and the ability to cut through thicker materials. Ultimately, between these two products, it comes down to what is more appealing to the customer, the freedom of the multiple uses of the dremel, or a jigsaw which provides a more stable cutting experience and is capable of cutting through thicker materials.
Table 5 provides a cost comparison for the various product alternatives.
|Hand Saw||Craftsman 20 in. Coarse 9 Pt. Carpenter Handsaw with Wood Handle||$15.99|
|Reciprocating Saw||DEWALT DW304PK 10 Amp Reciprocating Saw ||$99.00|
|Band Saw||Powertec 9" Band Saw ||$129.99|
|Scroll Saw||Rockwell RK7315 16-Inch Scroll Saw ||$115.76|
|Dremel||Dremel Trio Tool Kit ||$99.00|
|Jigsaw||Black and Decker Variable Speed Orbital Jigsaw JS660 ||$50.00|
Table 5 Cost Comparison
The Black and Decker Variable Speed Orbital Jigsaw JS660 is thus the cheapest electrically based tool within the list of alternatives.
 Black and Decker variable speed orbital jigsaw . (2011). Retrieved from http://www.blackanddecker.com/power-tools/JS660.aspx
 Black and Decker variable speed orbital saw instruction Manuel. (2010, March). Retrieved from http://servicenet.blackanddecker.com/documents/English/InstructionManual/90553228,JS660.pdf
 Craftsman 20 in. coarse 9 pt. carpenter handsaw with wood handle. (2011). Retrieved from http://www.sears.com/shc/s/p_10153_12605_00936264000P?blockNo=4&blockType=G4&prdNo=4&i_cntr=1318221524784
 Dewalt dw304pk 10 amp reciprocating saw . (2011). Retrieved from http://www.homedepot.com/Tools-Hardware-Power-Tools-Saws/DEWALT/h_d1/N-5yc1vZas2tZ4j2/R-100021472/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053
 Powertec 9" band saw. (2011). Retrieved from http://www.sears.com/shc/s/p_10153_12605_00926023000P?mv=rr
 Rockwell rk7315 16-inch scroll saw. (2011). Retrieved from http://www.amazon.com/Rockwell-RK7315-16-Inch-Scroll-Saw/dp/B002CJLUYW
 Dremel triotool kit. (2011). Retrieved from http://www.lowes.com/pd_148844-353-6800-01_4294857502_4294937087_?productId=3265393&Ns=p_product_prd_lis_ord_nbr%7C0%7C%7Cp_product_qty_sales_dollar%7C1&pl=1¤tURL=/pl_Rotary+Tools_4294857502_4294937087_?Ns=p_product_prd_lis_ord_nbr%7C0%7C%7Cp_product_qty_sales_dollar%7C1&facetInfo=