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| | + | ==Executive Summary== |
| | + | |
| | + | Our group was given a Pioneer 1074 chainsaw to dissect and analyze. This chainsaw was top of the line during it's day, however it is now 29 years old. Technology has not changed to much on chainsaws since then, but newer models have much more power. There are no specs online of the chainsaw that could be found. |
| | + | |
| | == Group info == | | == Group info == |
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| | -Busy Schedule | | -Busy Schedule |
| | |} | | |} |
| | + | |
| | | | |
| | == Gate 1: Request for a Proposal == | | == Gate 1: Request for a Proposal == |
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| | Gate 1 can be found [[Group_32_Gate_1 | here]]. | | Gate 1 can be found [[Group_32_Gate_1 | here]]. |
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| − | This Includes our work proposal, management proposal, Gantt Chart, and Initial Product Assessment. | + | This Includes our work proposal, management proposal, Gantt Chart, and an initial product assessment. |
| | | | |
| | == Gate 2: Preliminary Project Review == | | == Gate 2: Preliminary Project Review == |
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| | This includes any causes for corrective action, an analysis of the disassembly, and a step by step process of the disassembly. | | This includes any causes for corrective action, an analysis of the disassembly, and a step by step process of the disassembly. |
| − |
| |
| − | Our work and management proposals were successful with a couple conflicts along the way. The challenges in the disassembly were limited to removing the centrifugal clutch. This required an enormous amount torque. To do this we used a vice grip to lock up the crankshaft. Also, we had to use a metal rod to extend our moment arm. This challenge in disassembly was not predicted and caught us off guard.
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| − |
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| − | Following our management proposal we had left time in our disassembly process to handle any situations like the clutch removal. However, our initial plan to meet twice a week was found to be unnecessary. The full disassembly was done in two meetings, and a trip to the lab to remove the clutch.
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| − | After the Request for the Proposal was due, Andrew went to the lab and signed out the chainsaw. He then took it with him and did a quick analysis disassembly. By removing the three outer covers over the flywheel, clutch and intake, a secondary analysis for tools and challenges was done. This took him 25 minutes at most. This is where we found the clutch removal problem. Our list of tools required was confirmed.
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| − |
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| − | Our next meeting was at Cam’s apartment, where everyone gathered on October 15th at 5pm. For two hours we worked on the disassembly. During the disassembly we took photos of the whole step process and recorded our progress in an Excel document (see attached). At the end of the two hours we had removed everything from the main component up to the intake (see Chart 1 for details).
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| − | Next we met October 20th at the same place and time (Cam’s apartment @ 5pm). During this time we finished our disassembly. The next day we went to the lab to remove the clutch.
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| − | Overall, we have to say our disassembly was a success and we plan on continuing our management proposal into the next gates.
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| − |
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| − |
| |
| − | === Disassembly Process===
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| − |
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| − | {| cellspacing="0" border="1" style="margin: 1em auto 1em auto"
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| − | ! align="center" style="background:#00aa00;"|'''Step'''
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| − | ! align="center" style="background:#00aa00;"|'''Tool Used'''
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| − | ! align="center" style="background:#00aa00;"|'''Part Removed'''
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| − | ! align="center" style="background:#00aa00;"|'''Location on Product'''
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| − | ! align="center" style="background:#00aa00;"|'''Time it Took'''
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| − | ! align="center" style="background:#00aa00;"|'''Ease Rating 1-5'''
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| − | ! align="center" style="background:#00aa00;"|'''Directions'''
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| − | |-
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| − | |align="center"|1||Straight Blade Screw Driver||Intake Cover||Exterior||5 sec||align="center"|2||Turn the bolt 90 degrees and pull plastic cover off.
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| − | |-
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| − | |align="center"|2||Straight Blade Screw Driver||Intake Cover Locking||Underneath the intake cover||5 sec||align="center"|2||Remove the bolt.
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| − | |-
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| − | |align="center"|3||14 mm Socket & 1/4" Drive||Clutch Cover||Exterior||30 sec||align="center"|2||Remove both nuts and washers, and slide the cover off of the protruding bolts.
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| − | |-
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| − | |align="center"|4||None||Chain Bar||In between clutch and body||1 sec||align="center"|1||Slide it off of protruding bolts that hold it in place.
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| − | |-
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| − | |align="center"|5||Straight Blade Screw Driver||Handle||Exterior||1 min||align="center"|2||Remove all four bolts holding it in place.
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| − | |-
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| − | |align="center"|6||Straight Blade Screw Driver||Flywheel Cover||Exterior||1 min||align="center"|2||Remove all 3 bolts.
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| − | |-
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| − | |align="center"|7||Straight Blade Screw Driver||Bottom Exterior Cover||Bottom||1 min||align="center"|2||Remove all 4 bolts.
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| − | |-
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| − | |align="center"|8||crescent wrench||On/Off Switch||Attached to the bottom cover||5 sec||align="center"|2||Remove the thin nut holding it in place.
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| − | |-
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| − | |align="center"|9||Straight Blade Screw Driver||Muffler/Exhaust Cover||On the side, next to the clutch||30 sec||align="center"|2||Remove all 3 bolts attaching it.
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| − | |-
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| − | |align="center"|10||Straight Blade Screw Driver||Exhaust Header||Under the muffler/exhaust Cover||30 sec||align="center"|2||Remove all 3 bolts holding it in place.
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| − | |-
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| − | |align="center"|11||Spark Plug Wrench||Spark Plug||At the top of the cylinder||30 sec||align="center"|4||Remove the spark plug by twisting it.
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| − | |-
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| − | |align="center"|12||14 mm Socket & 1/4" Drive||Fly Wheel||Under the flywheel cover||30 sec||align="center"|3||Remove the bolt holding it onto the shaft protruding through the center of it.
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| − | |-
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| − | |align="center"|13||Straight Blade Screw Driver||Magneto and Spark Plug Wire||Beside the flywheel||15 sec||align="center"|2||Remove the 2 bolts holding it in place.
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| − | |-
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| − | |align="center"|14||Straight Blade Screw Driver||Spark Plug Timing Mechanism||Above the timing mechanism||3 sec||align="center"|2||Remove the clip/lock and pull plastic cover off.
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| − | |-
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| − | |align="center"|15||Straight Blade Screw Driver||Choke||Connected to the intake||15 sec||align="center"|3||Slide the choke out from intake.
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| − | |-
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| − | |align="center"|16||Straight Blade Screw Driver||Intake||On the top under the intake cover||10 sec||align="center"|2||Remove the bolt holding it in place and slide out.
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| − | |-
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| − | |align="center"|17||14 mm Crescent Wrench||Cylinder||Surrounding the piston and connecting rod, beneath the intake||5 min||align="center"|3||Remove all 4 of bolts and nuts.Then slide it off.
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| − | |-
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| − | |align="center"|18||Straight Blade Screw Driver||Battery||Next to the crankshaft, under the flywheel||10 sec||align="center"|2||Remove the 2 bolts holding it in place.
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| − | |-
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| − | |align="center"|19||None||Plastic Holder||Next to the crankshaft||.5 sec||align="center"|1||Pull it out.
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| − | |-
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| − | |align="center"|20||Straight Blade Screw Driver||Timing Mechanism||Surrounding the crankshaft outside of the crankcase.||5 sec||align="center"|2||Remove the bolt.
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| − | |-
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| − | |align="center"|21||Straight Blade Screw Driver||Left Half of Casing||Exterior||5 min||align="center"|2||Remove all 7 bolts attaching it to the other half of the body casing.
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| − | |-
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| − | |align="center"|22||None||Throttle and Cable||Inside the handle part of the external casing||1 sec||align="center"|1||Lift it out of place.
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| − | |-
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| − | |align="center"|23||Vice Grips, 15/16" Crescent Wrench, and Leverage Bar||Clutch Assembly||Attached to the crankshaft on the opposite side of the casing from the piston and connecting rod.||5 min||align="center"|5||Clamp the vice grips to the crank case in a position that will prevent the counter balance to pass it therefore keeping the crank shaft from spinning freely. Put the open end of the crescent wrench in the slots on the clutch and using a leverage bar in the other end of the wrench, twist in the direction of the arrow (reverse threaded) and pry it off.
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| − | |-
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| − | |align="center"|24||None||Crank Shaft, Piston, and Rod||Inside the crankcase and protruding from both sides||30 sec||align="center"|3||Twist and pull it out of place.
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| − | |}
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| − |
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| − | ''The Difficulty Scale is rated accordingly:''
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| − |
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| − | * 1 = No tool required
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| − | * 2 = One tool required with little force required
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| − | * 3 = One tool required with a large force required or an awkward positioning
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| − | * 4 = Multiple or specialized tools required with little force required
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| − | * 5 = Multiple or specialized tools required with a large force required
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| | | | |
| | == Gate 3: Coordination Review == | | == Gate 3: Coordination Review == |
| | | | |
| − | ===Component Summary===
| + | Gate 3 can be found [[Group_32_Gate_3 | here]]. |
| − | | + | |
| − | {| cellspacing="0" border="1" style="margin: 1em auto 1em auto"
| + | |
| − | ! width="120pt" align="center" style="background:#00aa00;"|'''Part'''
| + | |
| − | ! width="100pt" align="center" style="background:#00aa00;"|'''Material'''
| + | |
| − | ! width="200pt" align="center" style="background:#00aa00;"|'''Reason the Material Was Used'''
| + | |
| − | ! width="200pt" align="center" style="background:#00aa00;"|'''Manufacturing Process'''
| + | |
| − | ! width="200pt" align="center" style="background:#00aa00;"|'''Reason for the Shape of the Part'''
| + | |
| − | ! width="50pt" align="center" style="background:#00aa00;"|'''Quantity'''
| + | |
| − | ! width="250pt" align="center" style="background:#00aa00;"|'''Function'''
| + | |
| − | ! width="200pt" align="center" style="background:#00aa00;"|'''Forces Applied'''
| + | |
| − | ! width="50pt" align="center" style="background:#00aa00;"|'''Complexity'''
| + | |
| − | ! width="300pt" align="center" style="background:#00aa00;"|'''Photo'''
| + | |
| − | |-
| + | |
| − | | Main Casing||Aluminum Alloy||Aluminum is a light and cheap material and the alloy used is very durable||Molded and then tapping was used to create threaded holes||The part contours the hidden components while minimizing the total size of the chainsaw.||align="center"|2 parts||It houses all of the rest of the components.||The casing will endure any forces from dropping or misuse. Also, it supports the chainsaw's weight in the user's hands.||align="center"|1||[[Image:Chainsaw_Casing.jpeg|200px]]
| + | |
| − | |-
| + | |
| − | | Clutch Cover||Aluminum Alloy||Aluminum is a light and cheap material and the alloy used is very durable||Molded and then tapping was used to create threaded holes||The part contours the hidden components while minimizing the total size of the chainsaw.||align="center"|1||It covers and protects the clutch.||There should only be the force of the screws holding the cover on. However, the cover may endure forces from dropping or misuse.||align="center"|1||[[Image:Chainsaw_Clutch_Cover.jpeg|200px]]
| + | |
| − | |-
| + | |
| − | | Fly Wheel Cover||Aluminum Alloy||Aluminum is a light and cheap material and the alloy used is very durable||Molded and then tapping was used to create threaded holes||The part contours the hidden components while minimizing the total size of the chainsaw.||align="center"|1||It covers and protects the flywheel, and it also houses the starter unit which is a pull cord on a spring.||There should only be the force of the screws holding the case on. However, the cover may endure forces from dropping or misuse.||align="center"|1||[[Image:Flywheel_Cover.jpeg|200px]]
| + | |
| − | |-
| + | |
| − | | Bottom Cover||Aluminum Alloy||Aluminum is a light and cheap material and the alloy used is very durable||Molded||The part contours the hidden components while minimizing the total size of the chainsaw.||align="center"|1||It covers bottom of chainsaw.||There should only be the force of the screws holding the case on. However, the cover may endure forces from dropping or misuse.||align="center"|1||[[Image:Bottom_Cover.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Intake Cover||Plastic||Plastic is lightweight and the case should not undergo any strong forces.||Molded||The square shape maximizes the cross-sectional area available to the filter to allow for the largest intake volume.||align="center"|1||It covers intake and protects the filter from large debris.||There should only be the force of the screws holding the case on. However, the cover may endure forces from dropping or misuse.||align="center"|1||[[Image:Intake_Cover.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Fuel Lines||Rubber||Rubber is safe to use with oil and gasoline without contamination, and it can be easily moved to fit in many places.||Molded||A hose is the simplest method of transporting fluids and lightweight.||align="center"|3||It carries fuel from the tank to the intake and the cylinder. Also it carries excess gas out of the system.||The only forces acting on the fuel lines are negligible.||align="center"|1||[[Image:Fuel_Lines.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Pull Cord||Plastic handle and rope connected to a steel spring and plastic cover and plastic gear||The materials were selected to reduce weight||The handle was molded. The rope was wound, then knotted at one end and connected to handle. The plastic cover and gear wear also molded. The spring was extruded and bended.||The handle was made to fit in an average hand comfortably, while the other parts were shaped to perform their assigned tasks. The rope and spring are standard shapes, and the gears were made to allow the cord to engage the flywheel.||align="center"|1||The pull cord and assembly, start the rotation of the crankshaft and allow the chainsaw to start running.|| The forces applied are the external pull from the user, and the counter-torque from the flywheel, when it is engaged.||align="center"|3||[[Image:Pull_Cord.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Bar||Iron||Iron is a very strong material, and this part undergoes the main force of the chainsaw.||Pressed||The shape holds the chain in tension.||align="center"|1||It holds the chain in place, and transfers the driving force from the user to the wood.||This part undergoes the largest force, when the chainsaw is pushed into the wood.||align="center"|1||[[Image:Bar.jpg|200px]]
| + | |
| − | |-
| + | |
| − | | Cylinder ||Aluminum Alloy||The alloy used was chosen to reduce weight but still be strong enough to withstand the forces of general use. ||Molded and then milled||The cylindrical bore is the common shape for an engine to have for the chemical reaction to occur. There are two notches at the bottom of the cylinder to allow the oil and fuel to move in and out of the crankcase. The outside has spaces to allow air cooling of the cylinder during operation. ||align="center"|1||It houses the piston, and it is the location of the main source of energy, which is combustion.|| The cylinder undergoes a continuous change in forces as the chainsaw is used. The forces result from the expansion, heating, and compression of gases inside of it.||align="center"|1||[[Image:Cylinder.jpeg|200px]]
| + | |
| − | |-
| + | |
| − | | Spark Plug||copper, ceramic, and plastic||The copper is used to transfer the electric charge. The ceramic and plastic are used as insulators to prevent any shorting within the spark plug.||Molded, then threaded with a die||Spark plugs are always the same shape, to reduce size and allow the movement of charge easily.||align="center"|1||It provides a spark for the combustion.||The spark plug should only undergo the force from the gases.||align="center"|2||[[Image:Spark Plug.jpeg|200px]]
| + | |
| − | |-
| + | |
| − | | Handle & Grip||Steel and Rubber||The steel handle is very stiff and sturdy preventing any damage that may occur from the misuse of the chainsaw. The rubber grip reduces vibrations in the handle and makes it more comfortable to hold.||Molded and bent||The large handle allows for a wide variety of hand positions and gives you a sturdy grip.||align="center"|1||It allows the chainsaw to be held and manuevered accurately and comfortably.||The handle undergoes all of the forces the user applies to the chainsaw and the weight of the chainsaw acting on it.|| align="center"|1||[[Image:Handle1.jpeg|200px]]
| + | |
| − | |-
| + | |
| − | | Exhuast||Steel and Aluminum||Steel is used on the exterior of the exhaust to withstand any misuse and damage. Aluminum is used in the interior parts of the exhaust to save weight, and to absorb the vibrations from the engine.||Molded||The exhaust is shaped to maximize the noise reduction from the engine while still not getting in the way of the user. Also, the gases are directed away from the user off to the side to prevent inhalation or burns.||align="center"|3 pieces, 1 unit||It directs exhuast fumes out of the cylinder into the air and also muffles sound of the engine.||There should only be the force of the screws holding the exhaust on. However, the exhaust cover may endure forces from dropping or misuse.||align="center"|1||[[Image:Chainsaw_Exhaust.jpeg|200px]]
| + | |
| − | |-
| + | |
| − | | Heat Shield||Aluminum||Aluminum is a lightweight material that can deflect a decent amount of heat.||Bent and Pressed||The heat shield contours the cylinder around the edges facing the user. This causes the heat to be deflected away from the user.||align="center"|1||It guards the operator from the heat coming off of the cylinder||The only force exerted on this part is the compression force holding it in place.||align="center"|1||[[Image:Heat Shield.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Air Filter||Foam and Plastic||The foam is porous, allowing air to flow and dirt particles to be blocked.||Not Machined||The shape maximizes surface area to allow for a larger amount of filtering.||align="center"|1||It filters the air and protects the intake from taking in debris.||The only force on the filter is the flow of air entering the chainsaw.||align="center"|1||[[Image:Air_Filter.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Flywheel||Aluminum and Magnet||The magnet is necessary to trigger the magneto. The heavy aluminum creates a high rotational inertia keeping the crankshaft moving.||Molded||The fins on the flywheel allow air to be drawn in, cooling the system. The cylindrical shape has a radial symmetry, which is necessary for high rpms.||align="center"|1||It keeps the crankshaft spinning and triggers the magneto.||There is a torque applied to the flywheel from the crankshaft, and from the pull cord gear.||align="center"|1||[[Image:Flywheel1.JPG]]
| + | |
| − | |-
| + | |
| − | | Magneto||Iron, copper and rubber||Iron is necessary because it is highly affected by a magnetic field. The rubber insulates the signal and the copper transfers the signal with a low resistance.||Milled||The iron has two curved parts that match the curve and location of the magnets on the flywheel. The rubber casing and hosing is shaped to transfer the signal to the spark plug.||align="center"|1||It send signal from the flywheel to the spark plug.||There is a magnetic force exerted on the magneto from the flywheel.||align="center"|3||[[Image:Magneto1.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Ignition switch/cables||aluminum and copper wire||The aluminum is lightweight, and the copper has a low resistance for transferring current.||Lathed||The switch is small, but still large enough to easily be used.||align="center"|1||It allows the engine to start.||There is a force exerted on the switch whenever the chainsaw is turned on or off.||align="center"|2||[[Image:On_off_switch.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Battery and cables||Alkaline Battery and copper wire||N/A||N/A||The battery is a cylinder to maximize capacitance.||align="center"|1||It is the energy source for the electrical system.||N/A||align="center"|2||[[Image:Chainsaw Battery.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Fuel and oil caps||Plastic||Plastic is lightweight and fuel safe. Also it is easily molded.||Molded||The cap provides a large enough surface for the user to easily remove, and the thread holds the caps in tight.||align="center"|2||They help contain the contents of fluids in the tanks.||There is a torque applied by the user to remove and attach the caps. ||align="center"|1||[[Image:Fuel_Caps.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Spring loaded timing mechanism||plastic and aluminum||The aluminum is flexible allowing pressure to be provided to the cam and pin. The plastic is lightweight.||Molded and Bent||align="center"|N/A||align="center"|1||It controls the timing of the spark plug.||There is a force on the aluminum strip that holds it against the pin. A force is exerted against the plastic piece from the cam.||align="center"|2||[[Image:Cam_Timing_Mechanism.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Trigger and connecting wire||plastic and aluminum||The materials are used to reduce weight.||Molded and Bent||Plastic can be easily molded. The metal is a stock aluminum rod bent into the desired shape.||align="center"|1||It converts user input into mechanical system.||||align="center"|1||[[Image:Trigger1.jpg|200px]]
| + | |
| − | |-
| + | |
| − | | Piston ring||Steel||Steel has a higher boiling point then the aluminum parts around it, resulting in less expansion from heat. Also steel is a stronger material than aluminum.||Pressed||The ring has a gap to allow it to be slightly stretched and compressed to fit on the piston.||align="center"|1||It seals the wall of the cylinder to the piston and creates a ring of oil around the piston for lubrication.||The force from the expanding gases and friction from the cylinder are acting on the piston ring. Also, the piston ring moves along with the piston causing a transfer in forces between them.||align="center"|1||[[Image:Piston_Ring.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Timing mechanism cover||Plastic||The plastic is lightweight and flexible.||Molded||The cover is shaped to reduce the space it takes up, while fully covering the parts below.||align="center"|1||It prevents damage to timing mechanism.||N/A||align="center"|2||[[Image:Timing_Mechanism_Cover.jpg|200px]]
| + | |
| − | |-
| + | |
| − | | Timing mechanism switch||Aluminum||||Pressed||||align="center"|1||It completes the circuit with the battery.||||align="center"|2||[[Image:Timing Mechanism Switch.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Fuel ratio adjuster||Rubber and Iron||||||||align="center"|1||It Regulates fuel to air mixture.||||align="center"|2||align="center"|N/A
| + | |
| − | |-
| + | |
| − | | Air intake lock||Steel||||Pressed||||align="center"|1||It locks the air intake cover over the intake.||||align="center"|1||[[Image:Air_Intake_Lock.jpg|200px]]
| + | |
| − | |-
| + | |
| − | | Choke switch||Plastic||||Molded||||align="center"|1||It triggers the choke in the intake.||||align="center"|1||[[Image:Choke.JPG|200px]]
| + | |
| − | |-
| + | |
| − | | Intake||Aluminum, Plastic and Rubber Gaskets||||Die Cast||||align="center"|1||It regulates the air intake and mixes the air with the fuel.||||align="center"|5||[[Image:Intake1.JPG|200px]]
| + | |
| − | |-
| + | |
| − | |Piston||Aluminum Alloy||Aluminum is lightweight, machined with a low coefficient of friction.||Die Cast||The piston contours the cylinder with a slot cut into it for the piston ring. The shape is designed to minimize weight while maintaining strength.||align="center"|1||It transfers the pressure force from the expanding gases to the connecting rod.||The forces from combustion and expanding gas are acted on the piston. Also, the crankshaft exerts an initial force on the piston when the chainsaw is first started.||align="center"|1||[[Image:Piston2.JPG|200px]]
| + | |
| − | |-
| + | |
| − | |Connecting Rod||Aluminum Alloy||A high strength aluminum alloy was used, because it is easily machined, and has a high tensile strength.||Pressed||A single piece connecting rod was used to reduce weight, and there is no need for it to be disassembled many times.||align="center"|1||It transfers the mechanical force from the piston to the crankshaft.||Forces are transferred between the piston and the crankshaft via the connecting rod.||align="center"|1||align="center"|N/A
| + | |
| − | |-
| + | |
| − | |Crankshaft||Iron||Iron is used to endure the high stress, and to transfer high torque to the clutch.||Die Cast and cut in a lathe||a three part crankshaft was used because they are stronger and easier to machine.||align="center"|1||It transfers rotational motion between the clutch, flywheel, and piston.||High torque is transferred between the flywheel, piston and clutch.||align="center"|2||[[Image:Crankshaft4.JPG|200px]]
| + | |
| − | |-
| + | |
| − | |Clutch||Iron||Steel is very strong and the weight is needed to balance the flywheel.||Die Cast||Since the clutch is constantly rotating, it must be round. Also, the two springs cause the clutch to engage/disengage at a certain rotational velocity.||align="center"|1||It engages and disengages the gear connected to the bar at different rpm speeds.||A torque is applied from the crankshaft to engage/disengage the clutch.||align="center"|3||[[Image:Chainsaw Clutch.jpeg|200px]]
| + | |
| − | |-
| + | |
| − | |Bolts||Steel||Steel is a common material used for Bolts.||Molded and extruded through a die||||align="center"|40 (The different sizes are listed below)||They hold the parts together.||A torque is applied to attach/remove the bolt.||align="center"|1||[[Image:Bolts.JPG|200px]]
| + | |
| − | |-
| + | |
| − | |Nuts||Steel||Steel is a common material used for nuts.||Molded and tapped||Steel is strong, and a common material for nuts.||align="center"|11 (The different sizes are listed below)|| They help the bolts attach to the parts.||A torque is applied to attach/remove the nuts.||align="center"|1||[[Image:Nuts.JPG|200px]]
| + | |
| − | |}
| + | |
| − | | + | |
| − | ''The complexity scale is rated as listed below.
| + | |
| − | *1 = One or two parts that easily fit together
| + | |
| − | *2 = Three to seven parts that require some knowledge to assemble
| + | |
| − | *3 = Seven to twelve parts that require accuracy, and full knowledge of the products use, to assemble.
| + | |
| − | *4 = More than twelve parts that require full knowledge of the mechanical system.
| + | |
| − | *5 = It has many parts that require machines and careful examination to assemble.
| + | |
| − | | + | |
| − | {| cellspacing="0" border="1" style="margin: 1em auto 1em auto"
| + | |
| − | |+'''Flat Head Bolts'''
| + | |
| − | ! align="center" style="background:#00aa00;"|Length!!align="center" style="background:#00aa00;"|Thread Width!!align="center" style="background:#00aa00;"|Quantity
| + | |
| − | |-
| + | |
| − | | align="center"| 3/8"||align="center"| 1/8"||align="center"| 1
| + | |
| − | |-
| + | |
| − | | align="center"| 3/8"||align="center"| 3/16"||align="center"| 1
| + | |
| − | |-
| + | |
| − | | align="center"| 7/16"||align="center"| 3/16"||align="center"| 1
| + | |
| − | |-
| + | |
| − | | align="center"| 3/8"||align="center"| 3/16"||align="center"| 1
| + | |
| − | |-
| + | |
| − | | align="center"| 1 1/8"||align="center"| 3/16"||align="center"| 1
| + | |
| − | |-
| + | |
| − | |align="center"| 15/16"||align="center"| 3/16"||align="center"| 2
| + | |
| − | |-
| + | |
| − | |align="center"| 5/8"||align="center"| 1/8"||align="center"| 5
| + | |
| − | |-
| + | |
| − | |align="center"| 2 3/16"||align="center"| 3/16"||align="center"| 2
| + | |
| − | |-
| + | |
| − | |align="center"| 2 9/16"||align="center"| 3/16"||align="center"| 2
| + | |
| − | |-
| + | |
| − | |align="center"| 1 3/8"||align="center"| 3/16"||align="center"| 12
| + | |
| − | |-
| + | |
| − | |align="center"| 1 1/16"||align="center"| 3/16"||align="center"| 4
| + | |
| − | |-
| + | |
| − | |align="center"| 2 1/8"||align="center"| 3/16"||align="center"| 1
| + | |
| − | |-
| + | |
| − | |align="center"| 1/2"||align="center"| 5/32"||align="center"| 3
| + | |
| − | |}
| + | |
| − | | + | |
| − | {| cellspacing="0" border="1" style="margin: 1em auto 1em auto"
| + | |
| − | |+ '''Hex Head Bolts'''
| + | |
| − | ! align="center" style="background:#00aa00;"|Length!!align="center" style="background:#00aa00;"|Thread Width!!align="center" style="background:#00aa00;"|Head Size!!align="center" style="background:#00aa00;"|Quantity
| + | |
| − | |-
| + | |
| − | | align="center"| 1 3/16"||align="center"| 1/4"||align="center"| 7/16"||4 with lock washers
| + | |
| − | |}
| + | |
| − | | + | |
| − | {| cellspacing="0" border="1" style="margin: 1em auto 1em auto"
| + | |
| − | |+ '''Nuts'''
| + | |
| − | |-
| + | |
| − | ! align="center" style="background:#00aa00;"|Shape!!align="center" style="background:#00aa00;"|Size!!align="center" style="background:#00aa00;"|Hole Diameter!!align="center" style="background:#00aa00;"|Thickness!!align="center" style="background:#00aa00;"|Quantity
| + | |
| − | |-
| + | |
| − | | Square||align="center"| 7/16" x 7/16"||align="center"| 2/8"||align="center"| 3/16"||align="center"| 4
| + | |
| − | |-
| + | |
| − | | Square||align="center"| 3/8" x 3/8"||align="center"| 3/16"||align="center"| 1/8"||align="center"| 2
| + | |
| − | |-
| + | |
| − | | Hex||align="center"| 1/2" x 1/2"||align="center"| 5/16"||align="center"| 5/16"||align="center"| 2
| + | |
| − | |-
| + | |
| − | | Hex||align="center"| 9/16" x 9/16"||align="center"| 5/8"||align="center"| 3/16"||align="center"| 1
| + | |
| − | |-
| + | |
| − | | Hex||align="center"| 9/16" x 9/16"||align="center"| 7/16"||align="center"| 1/16"||align="center"| 1
| + | |
| − | |-
| + | |
| − | | Hex||align="center"| 3/8" x 3/8"||align="center"| 1/8"||align="center"| 1/8"||align="center"| 1
| + | |
| − | |-
| + | |
| − | |}
| + | |
| − | | + | |
| − | === Design Revisions ===
| + | |
| − | | + | |
| − | The design of the chainsaw is relatively obsolete because of its age. With it being 29 years old, there have been many advances in technology that we have today that could make the chainsaw significantly better.
| + | |
| − | | + | |
| − | :*One of these new design methods would be to put 2 piston rings around the piston head instead of the single one that is on our chainsaw now. This is not a very technologically advanced design but, it is very cheap to do and will help the consumer greatly. This ensures that if the primary piston ring breaks or wears down and releases the seal to the cylinder wall, there is a back up that will keep the chainsaw working properly without the need of emergency repair.
| + | |
| − | | + | |
| − | :*Another simple add on to the chainsaw would be a temperature gauge that reads the heat inside the cylinder. This is a simple way of making the consumer aware of lack of oil in the gas/oil mixture which is needed for the piston to work properly. This would be a much more expensive addition than the piston ring but it could save the chainsaw from complete uselessness. If a user knew that the chainsaw was becoming over heated, he could let it cool before the engine seized or fix the ratio of oil and gas.
| + | |
| − | | + | |
| − | :*One thing that is common with chainsaws today, which would be a great improvement on the chainsaw we have is an external fuel tank made of plastic. This tank would be cheaper to produce than its aluminum counterpart in our chainsaw. The disadvantages of the aluminum fuel tank is that the aluminum is heavier than the plastic the external tank would be made out of and that the fuel tank could have a larger volume if it was placed outside the body of the chainsaw instead of being crammed into the body. This would greatly benefit the consumer while also benefitting the company. The company would save a great amount of money switching from aluminum or an aluminum alloy to a cheaply mass produced plastic tank while the customer enjoys a lighter and longer lasting, in terms of refueling, chainsaw.
| + | |
| − | | + | |
| − | === Solid Model Assembly ===
| + | |
| − | | + | |
| − | We chose Autodesk Inventor 2010 for our solid modeling program. We did this because our solid modeling expert has been working with this program for 5 years, and he would not have to learn another programs' mechanics. We chose to model the piston assembly because it provides the main power for our system to work.
| + | |
| − | | + | |
| − | A video of our assembly can be found [http://www.youtube.com/watch?v=Y5-MoUDoq1A here]
| + | |
| − | | + | |
| − | The part and assembly files can be downloaded by clicking ->
| + | |
| − | [[Media:Chainsaw.zip]]
| + | |
| − | | + | |
| − | ''Also, a free 30-day trial of Autodesk Inventor can be downloaded [http://usa.autodesk.com/adsk/servlet/pc/index?siteID=123112&id=13723623 here]''
| + | |
| − | | + | |
| − | === Engineering Analysis ===
| + | |
| − | | + | |
| − | '''Problem Statement:
| + | |
| − | | + | |
| − | What is the frictional force needed for a 2-stroke engine to cease?
| + | |
| − | | + | |
| − | '''Diagram:'''
| + | |
| − |
| + | |
| − | '''Assumptions:'''
| + | |
| − | | + | |
| − | *Friction is constant around the entire cylinder
| + | |
| − | *Coefficient of friction between the piston and cylinder is .03
| + | |
| − | *The normal force at cease is 110N
| + | |
| − | *Temperature is constant
| + | |
| − | *Piston and cylinder made of Aluminum
| + | |
| − | | + | |
| − | '''General Equations:'''
| + | |
| − | | + | |
| − | Ff =u*N
| + | |
| − | | + | |
| − | '''Calculations:'''
| + | |
| − | | + | |
| − | Ff = .03*110N= 3.3N
| + | |
| − | | + | |
| − | '''Solution Check:'''
| + | |
| − | | + | |
| − | The values for the coefficient of friction and the normal force were obtained from [http://www.vtt.fi/inf/pdf/tiedotteet/2002/T2178.pdf VTT research] notes on the friction inside of a 2-stroke engine. This helps to confirm that the force I obtained is close to the actual force.
| + | |
| | | | |
| | + | This includes a component summary, some suggested design revisions, solid modeling of a main system, and an analysis of engine seizure. |
| | | | |
| | ==Gate 4: Critical Design Review== | | ==Gate 4: Critical Design Review== |
| | | | |
| − | ===Reassembly Process===
| + | Gate 4 can be found [[Group_32_Gate_4 |here]]. |
| − | | + | |
| − | {| cellspacing="0" border="1" style="margin: 1em auto 1em auto"
| + | |
| − | | align="center" style="background:#00aa00;"|'''Step'''
| + | |
| − | | align="center" style="background:#00aa00;"|'''Tool Used'''
| + | |
| − | | align="center" style="background:#00aa00;"|'''Part Removed'''
| + | |
| − | | align="center" style="background:#00aa00;"|'''Location on Product'''
| + | |
| − | | align="center" style="background:#00aa00;"|'''Time it Took'''
| + | |
| − | | align="center" style="background:#00aa00;"|'''Ease Rating 1-5'''
| + | |
| − | | align="center" style="background:#00aa00;"|'''Directions'''
| + | |
| − | |-
| + | |
| − | | 1||None||Crank Shaft, Piston, and Rod||Inside Crank Casing and Protruding from Both Sides||30 sec||align="center"| 2||Insert the parts back into the crankcase.
| + | |
| − | |-
| + | |
| − | | 2||Vice Grips, 15/16" Crescent Wrench, and Leverage Bar||Clutch Assembly||Attached to Crank Shaft on Opposite Side of Casing From Piston and Rod||5 min||align="center"| 5||Clamp the vice grips to the crank case in a position that will prevent the counter balance to pass it therefore keeping the crank shaft from spinning freely. Put the open end of the crescent wrench in the slots on the clutch and using a leverage bar in the other end of the wrench,twist in the direction opposite of the arrow (reverse threaded) and tighten the clutch on.
| + | |
| − | |-
| + | |
| − | | 3||None||Throttle and "Cable"||Inside the handle part of the casing||1 sec||align="center"| 1||Set the trigger onto shaft according to the picture.
| + | |
| − | |-
| + | |
| − | | 4||Straight Blade Screw Driver||Left Half of the Casing||Exterior||5 min||align="center"| 2||Screw in all 7 bolts holding the two sides of the casing together.
| + | |
| − | |-
| + | |
| − | | 5||Straight Blade Screw Driver||Timing Mechanism||Under the timing mechanism cover||5 sec||align="center"| 2||Bolt the timing mechanism back on. (*Make sure the contact trigger barely makes contact with the sensor to result in the right timing.)
| + | |
| − | |-
| + | |
| − | | 6||None||Plastic Holder||Next to Crank Shaft||.5 sec||align="center"| 1||Insert the plastic holder back in it's slot.
| + | |
| − | |-
| + | |
| − | | 7||Straight Blade Screw Driver||Battery||Next to Crank Shaft, Under Flywheel||10 sec||align="center"| 2||Screw the battery back in with the two bolts.
| + | |
| − | |-
| + | |
| − | | 8||14 mm Crescent Wrench||Cylinder||Surrounding Piston and Rod, Beneath Intake||5 min||align="center"| 3||Bolt the cylinder back on. Make sure the piston ring is compressed and the piston goes in straight. Also, check to make sure the intake port lines up with the casing.
| + | |
| − | |-
| + | |
| − | | 9||Straight Blade Screw Driver||Intake||Top, Under Intake Cover||10 sec||align="center"| 2||Slide the intake in, bolt it on, and connect the fuel line.
| + | |
| − | |-
| + | |
| − | | 10||Straight Blade Screw Driver||Choke||Connected to Intake||15 sec||align="center"|3||Insert the tab on the end of the choke onto the intake.
| + | |
| − | |-
| + | |
| − | | 11||Straight Blade Screw Driver||Spark Plug Timing Mechanism Cover||Above Timing Mechanism||3 sec||align="center"| 2||Place the cover back on and insert the clip onto the copper shaft.
| + | |
| − | |-
| + | |
| − | | 12||14 mm Socket & 1/4" Drive||Fly Wheel||Under Fly Wheel Cover||30 sec||align="center"| 2||Bolt the flywheel back on to the crankshaft.
| + | |
| − | |-
| + | |
| − | | 13||Straight Blade Screw Driver||Magneto and Spark Plug Wire||Beside the Fly Wheel||15 sec||align="center"| 3||Bolt the magneto back on. Make sure the magneto is as close to the flywheel as possible, but not touching it. Spin the flywheel a couple times to test the clearance.
| + | |
| − | |-
| + | |
| − | | 14||Straight Blade Screw Driver||Exhaust Header||Under Muffler/Exhaust Cover||30 sec||align="center"| 2||Screw the three bolts back on.
| + | |
| − | |-
| + | |
| − | | 15||Straight Blade Screw Driver||Muffler/Exhaust Cover||Side, Next to Clutch||30 sec||align="center"| 2||Reattach the exhaust using the three bolts removed.
| + | |
| − | |-
| + | |
| − | | 16||crescent wrench||On/Off Switch||Attached to Bottom Cover||5 sec||align="center"| 2||Slide the switch back into the bottom casing, and screw the thin hex nut back on.
| + | |
| − | |-
| + | |
| − | | 17||Straight Blade Screw Driver||Bottom Exterior Cover||Bottom||1 min||align="center"| 2||Bolt the cover back on using the four bolts. Leave the lower left (looking at the chainsaw from the user's view) bolt off.
| + | |
| − | |-
| + | |
| − | | 18||Straight Blade Screw Driver||Flywheel Cover||Exterior||1 min||align="center"| 2||Bolt the cover back on using 3 bolts.
| + | |
| − | |-
| + | |
| − | | 19||Straight Blade Screw Driver||Handle||Exterior||1 min||align="center"| 2||Bolt the handle back on using the four bolts, nuts and washers.
| + | |
| − | |-
| + | |
| − | | 20||None||Chain Bar||In between Clutch and Body||1 sec||align="center"| 1||Slide the bar back onto the bolts and the bolt that adjusts the chain tension.
| + | |
| − | |-
| + | |
| − | | 21||14 mm Socket & 1/4" Drive||Clutch Cover||Exterior||30 sec||align="center"| 2||Bolt the cover back on with the two washers and nuts.
| + | |
| − | |-
| + | |
| − | | 22||Straight Blade Screw Driver||Intake Cover Locking||Underneath Intake Cover||5 sec||align="center"| 2||Attach it using a single bolt.
| + | |
| − | |-
| + | |
| − | | 23||Straight Blade Screw Driver||Intake Cover||Exterior||5 sec||align="center"| 2||Place the cover over the intake, push the screw in and turn it 90 degrees.
| + | |
| − | |}
| + | |
| − | | + | |
| − | ''The Difficulty Scale is rated accordingly:''
| + | |
| − | | + | |
| − | * 1 = No tool required
| + | |
| − | * 2 = One tool required with little force required
| + | |
| − | * 3 = One tool required with a large force or accuracy required
| + | |
| − | * 4 = Multiple or specialized tools required with little force required
| + | |
| − | * 5 = Multiple or specialized tools required with a large force or accuracy required
| + | |
| − | | + | |
| − | ===Final Assessment===
| + | |
| − | | + | |
| − | ''Does your product run the same as it did before you disassembled it?''
| + | |
| − | | + | |
| − | The product still does not work. The pull start still gets jammed and slowly recoils, and the engine needs replacement parts in order to be repaired. Also, there is a hole in the crankcase preventing the chainsaw from ever working.
| + | |
| | | | |
| | + | This includes a step by step reassembly process, and a final assessment of the chainsaw. |
| | | | |
| | | | |
| − | ''What were the differences between the disassembly and the reassembly processes?''
| |
| | | | |
| − | During reassembly the same tools were used, however there is more detailed work required to make the chainsaw work. This includes a miniscule distance between the magneto and the flywheel, The timing of the spark plug must be accurately positioned, and the carberator must be tuned according to the manual. Overall we were able to reassembly the chainsaw with no problems.
| + | ==References== |
| | | | |
| − | <!-- add pictures | + | [1] "How Stuff Works: Chainsaws". How Stuff Works. 10 Oct 09. <http://home.howstuffworks.com/chainsaw.htm>. |
Our group was given a Pioneer 1074 chainsaw to dissect and analyze. This chainsaw was top of the line during it's day, however it is now 29 years old. Technology has not changed to much on chainsaws since then, but newer models have much more power. There are no specs online of the chainsaw that could be found.
This Includes our work proposal, management proposal, Gantt Chart, and an initial product assessment.
This includes any causes for corrective action, an analysis of the disassembly, and a step by step process of the disassembly.
This includes a component summary, some suggested design revisions, solid modeling of a main system, and an analysis of engine seizure.
This includes a step by step reassembly process, and a final assessment of the chainsaw.
