Group 4 - Toro Snowblower 1 - Gate 4

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Contents

Introduction

Below is group four’s gate four, product explaination. In this section of the project, we reassembled the Toro Snowblower and analazied the product as a whole. The report is detailed as follows: cause for corrective action (including problems we faced, solutions we proposed to those problems, and how those solutions played out), and a product archaeology (steps for reassembly). The product archaeology includes a scale of difficulty (an in-depth look at how we measured the difficulty of reassembly), the reassembly steps (a complete look at the reassembly), challenges faced (in the reassembly of the product), and design revisions (changes that would make the Toro Snowblower more marketable from our perspective). The objective of this gate is to outlay our analysis of our product in a more detailed manner, along with a reflection on problems that we faced and solutions to those problems.

Project Management

Cause For Corrective Action

As this is the final gate, our group worked well together as a whole. We encountered very little conflicts with our group. Most of our members pulled their own weight and everything was turned in on time. One of the biggest problems we faced was with meeting times. Normally for short meetings (problems we have encountered, deadlines that are approaching, and general concerns), we have found that meeting right after Introduction to Mechanical Engineering in the lecture hall, Knox 104, works quite well because everyone is in one place. For longer meetings, we have been meeting at night during lab times. The problem that arose was that members constantly had to miss meetings and lab times due to previous commitments or classes. One solution we proposed to solve this was to set up a Google Calendar so that every member knew we had a meeting and at what time we were meeting. This seemed like a good idea, but in practice most members did not check it often enough for it to be a reliable way to coordinate schedules. The easiest way was by meeting directly after MAE 277 in Knox 104 to discuss gates, problems, and Lab meeting times. Also, as a reminder, an hour before lab, everyone received a text message stating we had to be in the lab that night. Together these solutions seemed to work best, although there were a few occasions where a group member did not show up and did not tell us ahead of time they could not attend. To address this problem, since the member was not committed during lab time, they were assigned assignments that they could do outside of lab on their own time. Another challenge we faced previously was with the quality of the work submitted. We assigned one group member to re-read everything before the due date, and this worked very well for the last gate. We continued to do it for this gate. For past problems concerning posting to the wiki, we have been posting our information straight to the wiki after it is completed instead of waiting until the deadline. This has been very helpful because internal deadlines are met faster and there is limited waiting time between posting and getting documents that are meant to be posted. We do not have any current, unresolved problems. For the problems we had previously and during this gate, our solutions are stated above as to how we solved our problems.

Product Archaeology

Scale of Difficulty

Table 1: Explanation of Difficulty Scale.
Difficulty Color Meaning
Easy The reassembly step did not take any significant amount of time or effort to complete. Connecting components or subsystems was very straightforward and did not require a lot of deep thought on how to successfully complete the connection. There was minimal tool use, if any, and only required one person to complete.
Moderate For such steps, it may have been difficult to make a connection due to tight spaces or the awkward use of multiple tools. There was still no intense thought on how the components fit together, 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 put components or subsystems together. 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.

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 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.

Reassembly Steps

Table 2: List of reassembly steps.
Step # Picture Of Reassembly Reassembly Instructions Difficulty of Step Originally Assembled Same as Disassembly?
1
Chute
Figure 1: Inside of engine housing.
Reinsert the piston using flathead screwdrivers to compress the piston rings and a rubber mallet to hit it into the cylinder. Moderate: Difficult to keep rings compressed everywhere. The original manufacturer probably has a more specialized tool that makes this a lot easier to do. No, we just had to pull it out during disassembly.
2
Chute
Figure 2: Engine Housing.
Use a rubber mallet to reconnect the engine housing and then use 10 mm socket wrench and 10 mm open ended wrench to tighten the screws. Easy. Same. Yes.
3
Chute
Figure 3: Flywheel Assembly.
Mount the flywheel to the engine and then place the flywheel cup on top and screw the nut to the crankshaft with am 18 mm socket wrench. Easy. Same. Yes
4
Chute
Figure 4: Combustion Chamber Head.
Screw the combustion chamber head to the rest of the engine assembly with a 13 mm socket wrench. Easy. Same. Yes.
5
Chute
Figure 5: Armature-Magneto connected to the spark plug.
Screw the magneto-armature onto the engine with a 10 mm socket wrench and connect the lead to the spark plug. Easy. Same. Yes.
6
Chute
Figure 6: Muffler on left side of figure.
Screw the muffler to the engine using a 13 mm socket wrench. Easy. Same. Yes.
7
Chute
Figure 7: Plastic Primer Bracket.
Screw in the plastic bracket for the primer using a 5/16 socket wrench. Easy. Same. Yes.
8
Chute
Figure 8: Primer Pipe.
Screw the primer pipe to the engine using a Philips head screwdriver. Easy. Same. Yes.
9
Chute
Figure 9: Central Rotor Assembly.
Screw the rotor bracket to the rotor assembly using an 11 mm socket wrench and an 11 mm open ended wrench. Easy. Same. Yes.
10
Chute
Figure 10: Central Rotor Assembly.
Screw the rubber rotor blades to the center rotor bracket with an 11 mm socket wrench and 11 mm open ended wrench. Easy. Same. Yes.
11
Chute
Figure 11: Rotor Blades.
Screw the rubber rotor blades to the end of the rotor. Moderate: Difficult to get the screws through the rubber rotors. Same. Yes.
12
Chute
Figure 12: Choke Extractor.
Placed choke extractor on the user interface panel using a P1 screw driver. Easy. Same. Yes.
13
Chute
Figure 13: Manual Start Triangle Bracket.
Placed the manual start triangle on the manual start and using a 1/4 wrench to secure three .5 inch hexagon head screws to the manual start. Easy. Same. Yes.
14
Chute
Figure 14: Electric Start Motor.
Place the casing on the electric starter and secured six .5 inch hex head screws using a 10 mm wrench and 5/16 wrench. Easy. Same. Yes.
15
Chute
Figure 15: Electric Starter Box User Interface.
Place the electrical starter box into the user interface panel using a 1/4 wrench to secure three 1.25 inch hexagon head screws onto the user interface panel. Easy. Same. Yes.
16
Chute
Figure 16: Electric Starter Mounted to Engine Housing.
Place the electric starter casing to the engine housing and secure two .5 inch hexagon head bolts using a 10 mm socket. Easy. Same. Yes.
17
Chute
Figure 17: Key Ignition.
Place the key ignition on the user interface panel using hands to connect the key portion to the cable portion (sandwiching the user interface panel). Easy. Same. Yes.
18
Chute
Figure 18: Ice Scraper.
Place the ice scraper on the bottom frame and secure three .25 inch pan head bolt using an 11 mm socket wrench. Easy. Same. Yes.
19
Chute
Figure 19: Bottom Section of Frame.
Attach the bottom section frame to the bottom frame using an 11 mm socket wrench and an 11 mm open ended wrench to secure five .5 inch hexagon head screws. Easy. Same. Yes.
20
Chute
Figure 20: Mud Flap.
Place mud flap on bottom frame using an 11 mm socket wrench to secure three nuts to the screws that are attached to the bottom frame. Easy. Same. Yes.
21
Chute
Figure 21: Inner Left Side Panel.
Place the left side panel of the wheel frame on the engine housing and secure four .5 inch hexagon head screws using a 13 mm socket. Easy. Same. Yes.
22
Chute
Figure 22: Manual Start Pull Wheel.
Place manual start pull wheel on the motor mount and secure four .25 inch hexagon head screws using a 10 mm open ended wrench and a 5/16 socket. Easy. Same. Yes.
23
Chute
Figure 23: Engine.
Secure motor mount to engine casing using a 13 mm wrench to secure two nuts to the two screws of the combustion chamber/heat sink engine casing. Easy. Same. Yes.
24
Chute
Figure 24: Right Side Inner Panel.
Place the right panel of the wheel frame on the wheel frame and secure the two .5 inch hexagon head screws and one nut that connects to the center manual start triangle screw using an 11 mm socket wrench. Moderate: awkward angles and very tight working space. Same. Yes.
25
Chute
Figure 25: Inner Left Side Panel.
Place the inner left side panel on the main inner snow blower frame using hands and secure two .5 inch hexagon head using a 13 mm socket wrench and open ended wrench. Easy. Same. Yes.
26
Chute
Figure 26: Belt Drive Engine Pulley.
Place the belt drive engine pulley to the inner left side panel using a 1/4 craftsman open ended wrench, 3 mm Allen key and needle nose pliers to screw one .25 inch hex socket screw and one .25 inch square head screw. Difficult: Really tight spaces and small tools. Same. Yes.
27
Chute
Figure 27: Left Side Lever.
Place the left side lever mechanism on the left side inner panel and using a hex key (5/32) and 11 mm socket wrench to secure one .5 inch hex socket screw. Easy. Same. Yes.
28
Chute
Figure 28: Upper Handle.
Place the upper handle on top of the lower handle bar and secure eye bolt and three 1.25 button head screws using a 13 mm socket wrench and pliers. Easy. Same. Yes.
29
Chute
Figure 29: Throttle Bar Handle.
Place the throttle bar handle on the upper portion of the handle bar using hand force to lodge the throttle bar pegs in place. Easy. Same. Yes.
30
Chute
Figure 30: Top Portion of Chute.
Place top handle portion of the chute on the main chute portion and secure two .5 inch carriage screws using a 13 mm socket. Easy. Same. Yes.
31
Chute
Figure 31: Left Side Inner Bearing Housing.
Place left side inner bearing housing onto the left inner side panel and using an 8 mm socket and 10 mm socket to secure three .25 inch fillister head screws. Easy. Same. Yes.
32
Chute
Figure 32: Rotor.
Place rotor in the left side inner panel bearing housing hole using hands. Easy. Same. Yes.
33
Chute
Figure 33: Rotor Shaft Pulley.
Place the rotor shaft pulley on the inner left side panel on top of the rotor and secure using a hammer. Easy. Same. Yes.
34
Chute
Figure 34: Rotor Shaft Pulley.
Using a 11 mm socket, secure one .5 inch hexagon head screw from the rotor shaft pulley to the rotor. Easy. Same. Yes.
35
Chute
Figure 35: Left Side Panel Screws.
Place two .5 inch hexagon head screws on the left side panel connecting it to the wheel frame and secure with 13 mm socket wrench. Easy. Same. Yes.
36
Chute
Figure 36: Belt in Inner Left Side Panel.
Place belt on the gears in the inner left side panel using hands. Easy. Same. Yes.
37
Chute
Figure 37: Fuel Tank Line.
Connect the fuel tank line to the engine using pliers to secure the fuel line connections to the engine. Easy. Same. Yes.
38
Chute
Figure 38: Fuel Tank.
Place the fuel tank on the main frame and secure two .75 inch hexagon head screws using an 11 mm socket and open ended wrench. Easy. Same. Yes.
39
Chute
Figure 39: Fuel Tank.
Connect fuel tank line to the fuel tank using needle nose pliers to secure the fuel tank line connections to the fuel tank. Easy. Same. Yes.
40
Chute
Figure 40: Wheel.
Place left and right wheel on either side of the wheel frame shaft and pound button head fasteners into place to secure the wheels onto the shaft. Easy. Same. Yes.
41
Chute
Figure 41: Chute O-Rings.
Place chute O-rings on the main red frame using hands and secure mini bolts using hands. Easy. Same. Yes.
42
Chute
Figure 42: Metal Heat Shield.
Place metal shield heat engine vent using a flat head screwdriver, 10 mm socket and pliers to secure three .25 inch slotted hexagon head screws. Easy. Same. Yes.
43
Chute
Figure 43: Rotor Housing.
Place the inner rotor housing unit on the left side panel using a 11 mm socket wrench. Easy. Same. Yes.
44
Chute
Figure 44: Left Side Cover.
Place left side cover over the left side inner panel and secure five hex head screws (.75 inch, 1.25 inch, and .5 inch (three)) and their washers using a 10 mm socket. Easy. Same. Yes.
45
Chute
Figure 45: Snow Chute Collar Support Ring.
Place the snow chute collar support ring on the inner rotor housing unit and secure two 1 inch hexagon head screws using a 10 mm socket. Easy. Same. Yes.
46
Chute
Figure 46: Right Side Panel.
Place right side panel on chute casing and secure right side auger connection (three .5 inch hexagon head bolts) using an 11 mm socket wrench. Easy. Same. Yes.
47
Chute
Figure 47: Chute Casing.
Place snow chute collar support ring on the chute casing and secure using a 10 mm socket wrench to secure two 1-inch hex head screws. Easy. Same. Yes.
48
Chute
Figure 48: Chute Spring and Seals.
Attach chute o-ring seal and chute seal retainer that attaches to the outer red cover using a 9 mm socket wrench to secure two plastile screws. Then secure the spring lock-lever to the inside of the snow chute retainer using an 11 mm socket wrench and open ended wrench to secure four .75 inch hex head screws. Easy. Same. Yes.
49
Chute
Figure 49: Gas Cap.
Replace gas cap on fuel tank and secure using a turning of the hands. Easy. Same. Yes.
50
Chute
Figure 50: User Interface Panel.
Place the outside red coverings on the outside of the machine, and sandwich the outer covering with the user interface panel (the top and bottom) top and bottom. Secure the user interface panel using an 8 mm socket wrench to secure three hex washer head screws. Easy. Same. No, we had to connect the outer casing at the same time that we did the user interface panel.
51
Chute
Figure 51: Underside Red Casing.
Secure the underside of the red outside casing using a 10 mm socket wrench to secure two 1.5 inch hex head screws. Easy. Same. Yes.
52
Chute
Figure 52: Main Red Outside Cover.
Replace the main red outside cover screws and secure the two .75 Phillips pan head screws using a Phillips head screwdriver and 11 mm socket wrench. Easy. Same. Yes.
53
Chute
Figure 53: Chute.
Attach the base part and upper chute to the main red outside case and secure the three .5 inch carriage screw to using a 13 mm socket wrench. Easy. Same. Yes.
54
Chute
Figure 54: Bottom of Handle.
Secure bottom portion of handle using a 13 mm socket wrench and 13 mm open ended wrench to secure two .75 hex head screws to the main snow blower frame. Easy. Same. Yes.
55
Chute
Figure 55: Right Side Panel.
Secure right side panel using a 12 mm socket wrench to secure the remaining screws connecting the right panel to the main frame of the snowblower (some screws could not be secured at this time due to holes not matching up correctly or holes being in places we could not reach). Moderate: cramped corners. Same. Yes.
56
Chute
Figure 56: Throttle Cable.
Connect the throttle cable to the handle bars and the main snowblower frame using hands to lodge the cable clutch into the appropriate holes. Easy. Same. Yes.

Challenges Faced

Step 11 - Screwing in the Rubber Rotor Blades

The rotor blades are very hard to put back into place. The screws barely fit through the rubber rotor and took us about half an hour to screw in 8 screws. We overcame this challenge by screwing the rotor screws only to the rubber rotor which allowed the screw to get through the rubber rotor and then we could get the screws through the metal bracket at the end of the rotor.

Step 40 - Replacing the Wheels

During the disassembly, the fasteners got warped do to the difficulty in removing them from the axel. During the reassembly, they do not have the same holding power that they did, and came off very easily. We did our best to not move the snowblower, but even leaning it to the side would cause the fasteners to fall off. We tried to squeeze the fasteners to make them tighter to the axel, but nothing helped to make them tighter to the axel.

Step 55 - Screwing in the Right Side Panel

Several of the holes for the screws did not line up and we were therefore unable to screw all of the bolts into the right side panel. We also had trouble screwing in the bolts that actually fit because it was very tight behind the right side panel to use an open ended wrench.

Design Revisions

Increase Rotor Width and Height

Design Description: An increased rotor size and housing to accommodate it would increase the performance of the snowblower and allow it to be used in harsher winter conditions. An increase width would mean the snowblower could clear a wider area of snow at a given time. Increased rotor height would allow the snowblower to clear taller snow levels without the snow going over the rotor intake and potentially jamming the chute.

Societal Impact: The wider rotor would mean that the user would have to make less passes in order to clear an area of snow. This not only would make the act of using this machine easier because the user does not have to make as many turns, but it would also decrease the amount of time needed. Increased rotor height would mean that the user wouldn’t have to periodically clear the snow from the surface in order to keep it from building up. Thus, this revision helps make the product more user friendly, while also improving the performance of the product.

Global Impact: By increasing the rotor height the snowblower would be able to be used in regions that have a larger amount of snowfall. The snowblower would no longer be limited to a 2 foot snow height limit.

Economic Impact: Increasing the rotor size could cause a dramatic price increase in the product. Not only would the housing for the rotor, which is the body of the snowblower, and the rotor itself have to be redesigned, the engine and systems linking the engine to the rotor may have to be redesigned also. The rotor would encounter greater resistive forces thus requiring more power. Clearing this amount of snow would also require more forward force and thus, the snowblower might require a greater self propulsion system.

Gas Gauge Located on User Interface Panel

Design Description: Currently there is no way to tell how much gas is in the machine. This poses a problem because the user may run out of gas while operating the machine. A gas gauge located on the user interface panel would allow the user to tell if the machine has enough gas for their snowblowing needs before they start to use it.

Societal Impact: A gas gauge would increase the products ease of use. It is a hassle for the user to refuel the machine during the middle of using it, especially if they do not have extra fuel on hand. A gas gauge would allow the user to determine if it needed to be refueled ahead of time or if they needed to get more fuel before the snowblower needed to be used again and thus avoid this hassle all together.

Economic Impact: A gas gauge would slightly increase the production cost. Not only would the gauge itself have to be incorporated into the product, some type of sensor would also be needed in order to provide this gauge with fuel level information. A lower cost option would be a low fuel indicator light. A much simpler system would alert the user when there is not enough fuel left for a standard job.

Adjustable Handle

Design Description: Replacing the current handle with an adjustable handle would allow the user to choose their desired handle height. This could be done by replacing the bolts that hold the top section of the handle to the lower section with easy to remove bolts with handles on them and providing various holes to place these bolts through on the lower handle section.

Societal Impact: This product is intended to be operated by a variety of users and making the handle adjustable would provide better accommodations to users of different heights. This not only would make using the machine easier because the handle is at the correct height. It would also make it safer.

Economical Impact: Adding an adjustable handle would have very little price impact. Existing bolts would have to be swapped out for more user friendly ones and a few more holes would have to be drilled in the lower handle. This would have a marginal cost of production increase which could be countered by raising the price slightly due to this new feature.

Snow De-Jammer Located on Machine

Design Description: It is dangerous to remove a clog in the chute of the snowblower due to snow buildup because of the chutes proximity to the rotor. Removing this build-up should never be done by hand, however it is sometimes done because the user cannot find another object around in order to do the job. By attaching a tool to the machine that allows the user to unclog the chute, decreases this risk. The unclogging tool would be a molded plastic scraper that is attached with plastic clips to the top of the snow blower’s plastic casing.

Societal Impact: Including the correct tool to remove clogs would increase the products ease of use and safety. The user would no longer have to stop using the product and go in search of an object to remove the jam because it would be located directly in front of them. Providing the correct tool would also decrease the likelihood of the operator using their hand or other potentially dangerous objects to clear the jam. This would increase the safety of the product dramatically.

Economic impact: This addition would cause a slight increase in production cost. A plastic tool would have to be injection molded and plastic clips/screws to hold them on would have to be purchased. This however is a very low cost addition and the price of the product could be increased due to this new feature.