Group 4 - Toro Snowblower 1 - Gate 2

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Contents

Overview of the Gate

Gate 2 includes the dissection of the Toro snowblower, detailing the steps taken to remove each part and documenting the connections of the various subsystems. It also includes any revisions to the management plan from Gate 1.

Project Management

Cause for Corrective Action

Our work and management plans worked very well for this gate. Meeting directly after MAE277 in Knox 104 is convenient for all members because everyone is already in the same room and there are no scheduling conflicts. Every member has shown up each day we were in lab, with the exception of a scheduling conflict with a class and makeup test. No conflicts arose while we we in the lab. Work was received on time and no warnings were given out to any members.
A change should be made to the Gantt chart allowing more time to posting to the wiki as it is very time consuming and requires a large amount of trial and error to get the formatting correct. Also, the gates should not overlap as each gate has taken up until the due date to finish and post to the wiki. We may also want to designate a certain amount of time at the beginning of the next gate to post any corrections to the previous gates wiki page as opposed to waiting until the final due date to make these corrections.
We have avoided challenges during this gate by planning out who is doing what explicitly. Since everyone knew what part they played in the gate, we had no difficulties with any individuals in the group. We will continue to look ahead and assign work in advance so that there are never any challenges in getting work completed.

Product Archaeology

Scale of Difficulty

Table 1: Explanation of Difficulty Scale.
Difficulty Color Meaning
Easy This dissection step did not take a significant amount of time or effort to complete. Disconnecting components or subsystems was very straightforward and did not require a lot of deep thought on how to successfully complete the disassembly. There was minimal tool use, if any, and only required one person to complete.
Moderate For such steps, it may have been difficult to disconnect components or subsystems due to tight spaces or the awkward use of multiple tools. There was still no intense thought on how the components separated, but it may have taken more time to complete. In most cases, due to positioning of a fastener, two people were needed to complete the job.
Hard In these steps, profound thought had to be implemented in order to correctly separate

components or subsystems from each other. This required the majority of the group to figure out due to either the complexity of the reconnection or physical difficulty of putting the pieces together. The determination of proper tools took more time and thought than usual.

How This Scale Was Defined

In determining the difficulty of each step, factors such as thought, effort, time, tools, positioning of fasteners, and number of people needed were all taken into consideration. Setting a scale of easy, moderate, and hard makes a very straightforward statement in the actual difficulty of each step. In reading the definition of each subsequent level of difficulty, one can vividly see what makes the difficulty increase from easy to moderate to hard.

Disassembly

Table 2: List of disassembly steps.
Step # Picture Of Disassembly Disassembly Instructions Difficulty of Step Meant to be disassembled.
1
Chute
Figure 1: Exploded View of Chute.
Take off plastic chute using 13 mm socket wrench to unscrew the three .5 inch carriage screws to dislodge chute from the rest of the snow blower. Then using the 13 mm socket wrench, unscrew the two .5 inch carriage screws that connect the base and top portion of the chute together. Easy: Minimal tool use. This component is meant to be taken apart if needed. The chute is made of plastic and can potentially break. Therefore this part can be taken apart and repaired or replaced if needed.
2
Left Side Panel
Figure 2: Left Side Panel.
Take off the left side panel using a 10 mm socket wrench and pliers to unscrew the three hex head (.75 inches, 1.25 inches, and .5 inches) screws and their washers. Moderate: Hard to reach areas. This component was not meant to be taken apart. The bolts holding this part together are not in accessible locations.
3
Right Side Panel
Figure 3: Right side panel still on the snowblower.

Right Side Panel
Figure 4: Right side panel off of the snowblower.
At this point, we removed one hex socket button head screw from the right side panel using a 10 mm socket wrench and pliers to remove the attached nut, but as we quickly realized that it would be easier to revise our plan until we removed the outer casing to take a look inside the actual snow blower to see why the right side held so many more screws than the left. Easy: Minimal tool use. This component was not meant to be taken apart. There are many parts that are connected on this panel which must be disconnected before it can be removed.
4
Gas cap
Figure 5: Gas cap.

Gas cap removed
Figure 6: Opening where gas cap would be screwed on to.
Remove the gas cap from the outside of the red casing with a turning of hands. Easy: Simply unscrewing a gas cap. This component is meant to be taken apart. It is necessary to remove this component often in order to fill the fuel tank with fuel. The component easily screws on and off by hand.
5
Throttle Cable
Figure 7: Throttle cable end which connects to the handle.
Disconnect the throttle cable from the main handle using hands to dislodge the attachments from their holdings. Easy: No tools needed. This component is meant to be taken apart if needed. This part is easy to remove and can be replaced if broken or removed in order to fully remove the upper handle for storage.
6
Throttle Handle
Figure 8: Throttle handle.
Remove the throttle handle from the main handle bar using hands to dislodge the attachments from their holdings. Easy: No tools needed. This component is meant to be taken apart if needed. This component can be removed with two hands. It may be removed for compact storage or replacement.
7
Top Portion of Handle
Figure 9: Top portion of handle bar.
Remove the main top portion of the handle bar using a 13 mm socket wrench and pliers to remove the bolt eye and the three screws. Easy: One person, simple job. This component is meant to be taken apart. A few bolts allow this component to be removed for compact storage of the snowblower.
8
Throttle Cable
Figure 10: Throttle cable end which connects to the cable clutch.

Throttle Cable
Figure 11: Throttle cable.
Disconnect the throttle cable from the snow blower using hands to dislodge the cable clutch from the snow blower. Easy: No tools needed. This component is meant to be taken apart if needed. It can be easily removed or replaced if needed.
9
Instrument Panel
Figure 12: Instrument panel cover.
Remove the main instrument panel cover using an 8 mm socket wrench to unscrew the three hex washer head screws. At this point, we could not fully take the panel off due to the starter cable and other attachments that were connected to the engine. Easy: Minimal tool use. This component is meant to be taken apart if needed. It is easy to partially remove this component in order to access components in the instrument panel for repair or replacement.
10
Main Red Cover
Figure 13: Main red outside cover.
Remove the main red outside cover using a 12 mm socket wrench and Phillips head screwdriver to remove the two .75 inch Phillips pan head screws. Moderate: Hard to reach area for socket. This component is meant to be taken apart if needed. It is easy to remove in order to access the main components of the snow blower under it for repair or replacement.
11
Chute O-Ring Seal and Retainer
Figure 14: Chute o-ring seal and chute seal retainer.
Remove the chute o-ring seal and chute seal retainer from the under the red outside cover using a 9 mm socket wrench to remove the two plastile screws, and using finger nails to pry off the eight palnuts. Easy: Minimal tool use. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. It is difficult to access and the user should not need to perform service at this level.
12
Metal Heat Shield
Figure 15: Metal heat shield in place.

Metal Heat Shield
Figure 16: Metal heat shield.
Remove the metal shield heat engine vent using a flat head screwdriver, 10 mm socket wrench, and pliers to remove the three .25 inch slotted hex head screws. Moderate: Awkward to get to. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. The user is not meant to do service at this level so there is no reason for it to be easily accessible.
13
Spring Lock-Lever Still Connected
Figure 17: Spring and lock-lever still connected to the chute.

Spring Lock-Lever Removed
Figure 18: Spring and lock-lever removed.
Remove the spring and lock-lever from inside of the snow chute retainer using a 12 mm socket wrench and 12 mm open end wrench to unscrew four .75 inch hex head screws. Moderate: Bolt and nut were very rusty. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. There should be no reason to service this part of the snowblower.
14
Chute Collar Support Ring
Figure 19: Chute collar support ring still connected to the snowblower.

Chute Collar Support Ring
Figure 20: Chute collar support ring.
Remove the snow chute collar support ring using a 10 mm socket wrench to unscrew two 1.0 inch hex head screws. Easy: Minimal tool use. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. This is a durable part and should not need maintenance.
15
Right Side Panel
Figure 21: Right side panel still in place on the snowblower.

Right Side Panel
Figure 22: Right side panel.
Remove the right side panel using a 12 mm socket wrench to unscrew one .5 inch hex head screw, using a 14 mm socket wrench and 14 mm open ended wrench to unscrew one 1.5 inch hex head screw, using a 13 mm open ended wrench to unscrew one 1.5 inch hex head screw, using a 10 mm socket wrench and 12 mm wrench to unscrew two .5 inch hex head screws. Moderate: Many tools were used and took some time. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
16
Auger Connector
Figure 23: Auger connector.
Remove the underside of right side auger connection using hands. Easy: No tools needed. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. There is no reason for the user to ever remove this part.
17
Underside Red Cover
Figure 24: Underside red cover.

Underside Red Cover
Figure 25: Underside red cover.
Remove the underside of the red outside cover using a 10 mm socket wrench to unscrew two 1.5 inch hex head screws. Easy: Little effort. This component is meant to be taken apart if needed. It can be removed with a few steps in order to access components behind it for repair/replacement. There are numerous parts behind this piece that can be accessed once removed.
18
Lower Portion of Handle
Figure 26: Lower portion of the handle.
Remove the lower portion of the handle using a 13 mm socket wrench and 13 mm open ended wrench to remove the two .75 hex head screws. Hard: Very awkward to get to. This component is meant to be taken apart if needed. A few bolts allows this component to be removed for compact storage of the snowblower. Once removed the overall length of the snowblower decreases substantially.
19
Fuel Tank Line
Figure 27: Fuel tank line still connected to the fuel tank.
Disconnect the fuel tank line from the fuel tank using needle nose pliers to dislodge the connection. Easy: Minimal effort. This component is meant to be taken apart if needed. This component is easy to replace if it should fail. It is more likely to fail than other components because of its material.
20
Fuel Tank
Figure 28: Fuel tank.
Remove the fuel tank using an 11 mm socket wrench and 11 mm open ended wrench to remove four .75 inch hex head screws. Moderate: Tight quarters to work. This component was not meant to be accessed easily seeing that you must remove other parts and work in tight spaces, however it is possible to remove and replace if the fuel tank should fail.
21
Fuel Tank Line Connected to Engine
Figure 29: Fuel tank line still connected to the engine.
Disconnect the fuel tank line from the engine using pliers to dislodge the connection. Easy: Minimal effort. This component is meant to be taken apart if needed. This component is easy to replace if it should fail. It is more likely to fail than other components because of its material.
22
Belt
Figure 30: Belt.
Remove the belt from the gears under the left side panel using hands. Easy: No tools needed. This component is meant to be taken apart if needed. This component is easy to replace if it should fail. It is more likely to fail than other components because of its material and stress it endures. Accessing this component does require some work however.
23
Rotor Shaft Pulley
Figure 31: Rotor shaft pulley.
Remove the rotor shaft pulley from the inner left side panel using a 11 mm socket wrench five .5 inch hex head screws. Easy: Minimal Effort This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. The likelihood that this part become damaged and in need of repair is slim.
24
Rotor
Figure 32: Rotor removed from the snowblower.
Remove the rotor from the bottom of the left inner side frame using hands. Easy: No effort, gravity did the work. This component was not meant to be taken apart. In order to access this part one must first remove many other components that were not meant to be removed. This material is made of a material that should not become damaged and in need or repair.
25
Inner Left Side Panel
Figure 33: Inner left side panel with screws removed.
Remove the screws from the inner left side panel using 13 mm socket wrench and 13 mm open ended wrench to unscrew one .5 inch hex head screw, and an 11 mm socket wrench and 11 mm open ended wrench to unscrew two 1 inch hex head screws. Hard: Very tight quarters to work. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
26
Left Side Inner Bearing
Figure 34: Left side inner bearing housing and ball bearing.
Remove the left side inner bearing housing using an 8 mm socket wrench and a 3/5 inch open ended wrench to remove one .25 inch fillister head screw. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
27
Inner Rotor Housing
Figure 35: Inner rotor housing.
Remove the inner rotor housing using hands to remove from the left side panel. Easy: No tools needed. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
28
Spring
Figure 36: Pulley spring.
Remove the spring from the pulley system on the inner left side panel using needle nose pliers to pry the spring connection out of it’s connection hole. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
29
Lever Mechanism
Figure 37: Left side lever mechanism.
Remove the left side lever mechanism using a hex key (532) and 11 mm socket wrench to remove one .5 inch hex socket screw. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
30
Belt Drive Engine Pulley
Figure 38: Belt drive engine pulley.
Remove belt drive engine pulley from the left side panel using a ¼ craftsman open ended wrench, 3 mm Allen key and needle nose pliers to unscrew one .25 inch hex socket screw and one .25 inch square head screw. Hard: Various tools required. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
31
Inner Left Side Panel
Figure 39: Inner left side panel removed from the snowblower.
Remove the inner left side panel using hands to take it off the snow blower frame. Easy: No tools required. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
32
Wheel
Figure 40: Wheel removed from the snowblower.
Remove the nut push from the left side of the wheel and remove the wheel from the frame. Hard: Difficult to determine what tool to use and also took a good amount of man power. This component was not meant to be taken apart. The connection holding the wheel on is a permanent one that must be destroyed in order to be removed.
33
Wheel
Figure 41: Wheel and nut still attached to the snowblower.
Remove the nut push from the right side of the wheel and remove the wheel from the frame. Hard: Difficult to determine what tool to use and also took a good amount of man power. This component was not meant to be taken apart. The connection holding the wheel on is a permanent one that must be destroyed in order to be removed.
34
Motor Mount
Figure 42: Motor mount.
Take out the right side motor mount screws using 11 mm socket wrench and open ended wrench to unscrew four .5 inch hex head screws. Moderate: Required the use of multiple tools. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. Service at this level should not be done by the user.
35
Left Side Motor Mount
Figure 43: Left side motor mount without screws.
Remove the left side motor mount screws using a 13 mm socket wrench and hammer to unscrew two .5 inch hex head screws. Moderate: Required the use of multiple tools and a bit of manpower. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. Service at this level should not be done by the user.
36
Screw
Figure 44: Screw connecting the bottom frame and mudflap.

Mudflap
Figure 45: Mudflap removed from the snowblower.
Remove five .5 inch hex head screws from bottom frame using an 11 mm socket wrench and wrench to remove the mud flap. Moderate: Required the use of multiple tools. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. The mud flap does not encounter much stress and thus should not need to be repaired or replaced.
37
Motor Mount Bracket
Figure 46: Motor mount bracket removed from the snowthrower.
Take off the motor mount bracket using a 13 mm open ended wrench. Easy: Single tool and minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. Service at this level should not be done by the user.
38
Bottom Section of Bottom Frame
Figure 47: Bottom section of bottom frame.
Remove screws from bottom frame using 11 mm socket wrench and open ended wrench to take off bottom section of bottom frame. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
39
Gear
Figure 48: Gear removed from the engine.
Remove large gear from engine using a 13 mm socket wrench and open ended wrench. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. Service at this level should not be done by the user.
40
Bottom Frame Support
Figure 49: Bottom Frame Support.
Remove bottom frame support using an 11 mm socket wrench to unscrew one .25 inch hex head screw, one .10 inch button head screw, and two .10 inch hex head screws. Moderate: Took minimal amounts of tools and effort but two of the bolts broke off due to rust. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. In order to access this part a majority of the snowblower must first be removed.
41
Ice Scraper
Figure 50: Ice Scraper.
Remove the ice scraper from the bottom frame using an 11 mm socket wrench. Moderate: Made difficult due to rust. This component is meant to be taken apart if needed. This part can easy be worn down by extensive use and is easily accessed and replaced.
42
Muffler
Figure 51: Side view of muffler removed from the snowblower.

Muffler
Figure 52: Top view of muffler removed from the snowblower.
Remove the muffler using 13 mm socket wrench to unscrew two 3.5 inch hex head screws. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. The muffler should endure no damage while in operation.
43
Rotor
Figure 53: Rotor with bracket screws removed.

Rotor Blade
Figure 54: Rotor blade.

Rotor Bracket
Figure 55: Rotor bracket.

Center Console
Figure 56: Center console of the rotor assembly.
Disassemble the rotor assembly using an 11 mm socket wrench and 11 mm open ended wrench to unscrew four .5 inch hex head screws, and six .5 inch Phillips head screws (take off screws using 11 mm socket wrench and wrench holding the middle bracket that holds the two rotor blades together, using a Torx T25 to take off bolts and using 11 mm socket wrench to take off end bolts, remove the center console from rotor base using size 11 mm socket wrench and wrench). Moderate: Required the use of multiple tools and a bit of effort. This component was not meant to be taken apart. The rotor assembly needs to be removed before it can be disassembled easily. In order to access this part and remove it one must first remove other components that were not meant to be removed.
44
Key Ignition
Figure 57: Key ignition.
Remove the key ignition with hands. Easy: No tools required. This component was meant to be replaceable if need be. One must remove a few parts in order to access it. However, the difficulty level is low.
45
Battery
Figure 58: Battery.
Remove the battery using a 10 mm open ended wrench to unscrew two 1 inch hex head screws. Easy: Minimal effort. This component is meant to be taken apart if needed. The battery can die after time and it is possible to replace it. It is an easy part to access.
46
Manual Start Triangle
Figure 59: Manual start triangle and where it is attached to.

Manual Start Triangle
Figure 60: Manual start triangle.
Remove the manual start triangle using ¼ wrench to unscrew three .5 inch hexagon head screws and then unscrewing the pressed head screw by hand from the console. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
47
Electric Starter
Figure 61: Electric starter.
Remove the electric starter using a 1/8 Phillips head screw driver to unscrew two 3 inch Phillips pan head screws, and two .5 inch hexagon head screws. Easy: Minimal effort. This component is meant to be taken apart if needed. This component can be taken off and replaced if necessary. However, it does require other minor disassembly in order to access.
48
Electric Start
Figure 62: Electric start with casing half removed.

Electric Start
Figure 63: Electric start with the casing fully removed.
Remove the casing from the manual start wheel using a 10 mm wrench and a 5/16 wrench to remove six .5 inch hex head screws. Moderate: Required multiple tools and a bit of effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
49
Electric Start
Figure 64: Electric start and electric starter box.

Electric Start Box
Figure 65: Electric start box next to where it was mounted.
Remove the electrical starter box from the user interface panel using a ¼ wrench to unscrew three 1.25 inch hexagon head screws. Easy: Minimal effort. This component is meant to be taken apart if needed. This component can be taken off and replaced if necessary. However, it does require other minor disassembly in order to access.
50
Engine Primer
Figure 66: Inside of engine primer.
Remove the engine primer using a P2 screw driver to unscrew two 2.5 inch Phillips pan head screws, and four .5 inch Phillips pan head screws. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. Service at this level should not be done by the user.
51
Primer Engine Pipe
Figure 67: Primer engine pipe removed from the engine.
Remove the connector that connects the to primer and to the engine pipe using a P2 screw driver to unscrew two .5 inch Phillips pan head screws. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. In order to access this, a large amount of parts must be removed.
52
Choke Extractor
Figure 68: Choke extractor removed from the snowblower.
Remove the choke extractor using a 1/8 flat head screw driver. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. Service at this level should not be done by the user.
53
Combustion Chamber Screws
Figure 69: Outside of combustion chamber with screws removed.
Remove the screws from the combustion chamber head using a hammer and a 13 mm open ended wrench to unscrew two hex head 2 inch screws, two 2.75 inch cylinder head screws. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. The engine was not meant to be disassembled by the user.
54
Spark Plug
Figure 70: Spark plug and combustion chamber.
Remove the spark plug from the combustion chamber using a ¾ inch wrench. Easy: Minimal effort. This component was meant to be taken apart. It can deteriorate and possibly need to be replaced every year.
55
Plastic Primer Bracket
Figure 71: Plastic primer bracket.
Remove the plastic bracket for the primer using a 5/16 inch nut driver to remove one .5 inch hexagon head screw. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed.
56
Engine Cup Removal
Figure 72: Engine cup being removed.

Engine Cup
Figure 73: Top view of engine cup after removal from snowblower.

Engine Cup
Figure 74: Side view of engine cup after removal from snowblower.
Remove the engine cup using a hammer, vice grips and 18 mm socket wrench. Moderate: Required the use of multiple tools including a clamp and a good amount of effort. This step is on the verge of being "hard" on the difficulty scale. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. Any service of the engine should be done by a professional.
57
Engine Casing
Figure 75: Half of the engine casing removed to give a side view of the engine.
Remove engine casing using 10 mm socket wrench, 10 mm nut driver, and hammer to remove six 1.5 inch hex head screws, two 1.75 inch Phillips pan head screws. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. Any service of the engine should be done by a professional.
58
Piston
Figure 76: Piston removed from the chamber.
Remove the piston from the casing using a hammer to push the piston out of the casing. Easy: Minimal effort. This component was not meant to be taken apart. In order to access this part one must first remove other components that were not meant to be removed. Any service of the engine should be done by a professional.

Documentation of Subsystems

How Connections are Implemented

Connections of components and subsystems are based on a few key factors. First of all, the connection must make sense in the physical world. It would by physically impossible for the rotor blades to be connected by mass to the fuel tank. Components must come together in ways that they can work together without effecting another components operation. Connections must also be implemented in such a way that the system as a whole is as compact and user-friendly as possible. The snow blower is put together the way it is so that a wide variety of consumers can easily use and maneuver it while performing their job. The parts and subsystems are connected in such a way that the performance of the overall system is enhanced to its peak point. Performance in the case of the snow blower would come in the context of usability, maneuverability, power, and overall quality of relocating snow. Lastly, the four factors of engineering design are certainly considered before manufacturing a final product that is ready to be placed for sale. Societal, economic, global, and environmental factors all play a significant role in determining the set up of the snowblower.

Connections of Subsystems

There are several subsystems that make up the Toro snow blower and allow it to achieve its primary function of displacing snow. The subsystems can be broken down into functions and then further into components that act as subsystems. The main functions are moving the snowblower, picking up the snow, directing the snow, a user interface and powering the snowblower. These are further broken down into components in which include the chute, handle, rotor drive, choke, wheels, rotor housing, rotor, fuel tank and engine. Lastly, the user interface is made up of the electric start, key ignition, primer and manual start.

Physical Connections

The engine is connected to several subsystems physically, and they are the key ignition, primer, manual and electric starts, choke, rotor, rotor drive and the gas tank. The rotor drive is connected physically to the handle as well. The engine is connected to the primer by a tube, the manual start by a flywheel, the electric start by the drive starter, the choke by the linkage, the rotor by a belt, the rotor drive by a cable and lastly to the gas tank by a fuel line. The rotor drive is connected to the handle by being inserted in a hole in the handle on each side.

Energy Connections

The rotor drive is connected to the rotor by the distribution of energy as when pulled back it acts as a throttle allowing the engine to distribute power to the rotor. Also, the rotor is connected by energy to the wheels because it propels the machine forward and as it does this, the wheels follow in turn by rotating forward with the rotor. The engine is also connected to the rotor through energy distribution because it uses kinetic energy to rotate the belt that connects the rotor to the engine therefore rotating the rotor.

Mass Connections

The chute is connected to the rotor by mass distribution because when the rotor picks up snow it propels it through the chute.

Signal Connections

The key ignition and the two separate starting methods, manual and electric, are connected through signals. The key must be turned to the on position for either of the start methods to work. It sends a signal unlocking the ability to start the engine.

All of these subsystems are connected to create an overall system whose goal is to displace snow. The engine is connected to the ignition to allow it to be started, to the manual and electric starts along with the primer and the choke so it can be started, the fuel tank so it has a way to produce power, and to the rotor and rotor drive so it can distribute power. The rotor drive is connected to the handle so it is accessible to the user and it is connected to the rotor so it can act as a throttle. The chute is connected to the rotor so that the snow can be lifted and displaced and the rotor is connected to the wheels so the machine can easily self propel itself.

Influence of Subsystem Arrangement

Societal
  • A muffler is physically connected to the engine assembly in order to reduce the resonation of sound. This makes for a bearable noise output while snow blowing in neighborhoods or other highly public places.
  • An electric start is physically and signally connected to the engine so that if a person is too weak, old, or just does not want to utilize the pull start, they can simply press a button to start the snowblower.
Economic
  • Generally inexpensive metal and plastic is used to physically connect many of the subsystems.
  • Many of the same type and size nuts and bolts are used which makes them less expensive to mass produce since a small variety is utilized.
Environmental
  • A plastic scraper is physically connected to the bottom of the snow blower, which is unaffected by potential oxidation unlike a metal scraper.
  • A physical connection between the primer and engine allows for easier start up in a cold environment.
Global
  • The use of many metric nuts and bolts to physically connect the majority of the subsystems makes the snow blower’s disassembly or routine maintenance possible on an international level. All of these fasteners can be produced and/or purchased all around the world.
Performance
  • Performance is a key factor that influences the design and compilation of the overall subsystem arrangement. Subsystems are connected by a mean that will yield the most positive results. Optimal performance needs to be calculated, thus determining the way a subsystem will be connected. Performance within the context of a snow blower comes in terms of usability, maneuverability, and the overall quality in snow removal from the desired area. The performance of the snow blower must be most advantageous in order to meet the needs of the consumer, while also benefitting the company’s reputation.

Arrangement of Subsystems

  • The subsystem arrangement is designed so that the snow blower is as compact as possible, while each subsystem can efficiently interact with another in an organized fashion.
  • The handle assembly is connected to the rotor drive assembly for optimal control of the machine.
  • Among the top of the handle assembly lays the manual throttle bar which is connected to the engine by means of wire. This arrangement allows the user to effectively make the engine turn the rotor. This in turn provides the system the ability to achieve forward motion; all with the user safely walking behind the machine.
  • The fuel tank, muffler, and engine are all arranged together very closely for they must interact directly in order to perform as optimally as possible.
  • The engine gives the rotor the ability to turn the blades which are positioned in such a fashion that snow is able to be successfully forced up and out of the overall system through the chute.
Subsystems That Cannot Be Adjacent
  • The handle assembly cannot be adjacent to the snow chute for the snow being projected from the chute will interfere with the person using the snow blower.
  • The blade assembly cannot neighbor the majority of the other subsystems such as the engine and handle assembly for the rotating blades would cause damage to other components or the person physically attached (holding on) to the handle. Hence, the rotor and blades are housed in an enclosed body which physically confines its rapid motion from the rest of the machine.

Functional Model

Functional Model
Figure 77 : Functional Model of the Toro Snowblower