Group 27 - Pressure Washer

There were many Alan bolts that we had to remove during the dissection. Unfortunately, a select few of these Alan bolts and Phillips heads stripped. The nature of the shape of the hexagonal Alan key makes it susceptible to stripping. The hexagon is close in shape to a circle, and it does not take much stripping before the Alan key is no longer able to “catch” inside the hex bolt. The stripping is caused by the high moment resistance the bolts give to being loosened, as they are tightly screwed into place.

A solution would be to replace the Alan bolts with square bolts. These square bolts can withstand much more torque before stripping, when compared to the hex bolt. The square bolt, however, can still be loosened with a square Alan key. They Alan key shape is ideal for counteracting a large moment resistance, as it creates distance from the pivot point. It would be difficult to create enough torque with a regular screwdriver.

II. Push start instead of pull start

When contemplating design revisions it is important to keep in mind that how easy a product is to use can be just as important as its functionality, as it helps market the product. The pressure washer we are using is mainly targeted towards the everyday household consumer. Therefore, it is important that the product is able to limit the frustration associated with accomplishing the task at hand. That is, to make it easier to remove dirt or oil from a specific surface. While the pressure washer greatly reduces the effort required to clean a surface, it adds different tasks in the process. One of these tasks is the pulling the pull chord to start the motor. This job can be difficult for someone who does not have the necessary strength to pull the chord fast enough.

A push start pressure washer would eliminate the need to pull a chord, and make pressure washing that much easier. With the most physically challenging part of pressure washing eliminated, it would be extremely easy to get started with the cleaning process. Adding a push start would target an consumer audience that appreciates a product that is easy to use, and has few steps between readying it and using it. Such consumers would pay a little bit more for a push start feature, as it is an additional component that must be manufactured and assembled.

III. Ability to access other water supplies

Unlike the electric versions, gas operated pressure washers are not limited to their electric chord length and its distance relative to an electrical outlet. This means the gas versions are certainly more versatile, and have more mobility. Yet, a gasoline powered still has one important factor which limits its mobility. A typical gas pressure washer must be connected to a hose that connects to a water spout. This usually not a problem, as most surfaces which require cleaning are close to a spout. There are certainly circumstances, however, where a surface not near a water spout needs cleaning. For example, a large cargo vessel has a very large deck surface, yet there is not adequate water supply for a conventional pressure washer to attach to.

If a pressure washer was able to draw water from other bodies of water, in addition to a garden hose, it would be more useful in certain situations. Instead of attaching to a water spout, the washer’s intake hose could be hung over the side of the cargo ship and submerged into the ocean. The pressure washer could then use ocean water as its water supply. The difficulty that arises in such a design is, simply put, pressure. A typical water spout on the side of a house already has pressure, as evidence from the function of a typical garden hose. Therefore, when a pressure washer connects to it, it only needs to add to the pressure that it already produced by standard water lines. If a pressure washer were to draw from a different body of water, it would need a more powerful pump to create a high water pressure. Such a pressure washer would also be beneficial in areas such as rural land or heavily wooded areas, where conventional waterlines are not available.

There might be a significant price increase if the washer were able to draw from different water sources, due to the cost of a more powerful pump. The target market for this type would most likely be professional contractors and large companies, as the average homeowner would have no use for such a device.

Gate 2

Causes for Corrective Action

Our group has tried it’s best to stick to our original work and management plans. It is extremely difficult, however, to predict - with a high degree of accuracy - what problems may be encountered. Many variables such as group member availability, exact difficulty, time requirements for project segments, and group member strengths and weaknesses can change over the course of time. Naturally we’ve varied slightly from our original work assessment. We do not view slight differentiation as a step backwards, but rather a step in the right direction. As we continue to work together we build a stronger understanding of who excels where in the various aspects of reverse engineering, and how to communicate more effectively with each other. This is the first reverse engineering project for all members of the group and we’re viewing it as an awesome learning experience.

The original layout for our timeline as well as who is proprietor for each task has been adjusted in order to increase the quality of work and group input. The original timeline, as shown by our gantt chart, has the majority of tasks delegated to one or two group members.

For the Request for Proposal, the Work Proposal was assigned to Matt Fasoldt and Chris Wojiechowski. The Management Proposal was assigned to Cody Boppert. The Gantt chart was assigned to Tom Matikainen. Finally, the Initial Product Assessment was completed by Chris Kujawinski. We tried to assign these tasks based on everyone’s talents, and we were successful overall. Most members stayed within their assigned tasks, and the Request for Proposal was completed with few drawbacks. We were able to stay within the time constrictions and were not forced to finish work after the proposed deadline. The original plan was successful due to the fact that we correctly accounted for each member’s strengths, and catered the task assignments accordingly.

Management Proposal

We received full credit on the Overview of Plan and Roles and Responsibilities portion of the Management Proposal. The drawbacks for the management proposal consisted of our inability to clearly understand and pay attention to the directions listed in the assignment, combined with group miscommunication. Originally the Management Proposal was assigned to Tom Matikainen and Cody Boppert. Cody Boppert was given the written portion. The gantt chart, which was believed to be part of the Management Proposal at the time, was assigned to Tom Matikainen. The written portion was completed by Cody Boppert and afterwards revised and edited by Chris Kujawinski. During this time we completely overlooked the Conflict Resolution requirement and Meeting Proposal. As a result, the Management Proposal was submitted incomplete and our group received no credit for those missing portions.

Not only have these missing portions directly affected our grade, they have affected group performance. Without a plan for conflict resolution and a meeting proposal, congregating and completing assignments have become, to some extent, chaotic. Without each group member’s class schedule and available times, it has been difficult to predict when we can meet together. Consequently, meeting times and locations have become somewhat of a last minute decision, decided on the same day. Although we have not ran into any major conflicts, as of now, it is critical that we lay out a plan for how to deal with any and all likely problems that will arise. Without a fall back plan our group could find itself stuck, behind schedule, or with subpar work being submitted.

To get ahead of this project, and to excel above the class average, it is imperative that we, as a group, generate a Conflict Resolution plan as well as a Meeting Proposal. The fact that these sections were missing from the Management Proposal is not a reflection on any one group member (this mentality would not help the group), but rather a reflection on the group as a whole. We need to read assignments more carefully, ensuring every aspect of the listed requirements is present in our submission. We need to communicate more effectively and speak up if we believe work is not being done properly or completely. Finally, our group needs to view every part of each gate as if it were entirely their responsibility. We cannot however all take the whole project as our responsibility, and then proceed to overlap, but forget. In gate 2, three members took pictures, but no one took pictures of the gun, or the host. This means we all need to overlook each other’s work. This way any problems, such as missing information, will be less likely to slip through the cracks and go unnoticed.

The last thing that has caused problems is the editing of the wiki. With the extension of the deadline, our wiki guy did not have quite the time needed to make sure everything would go as smoothly as one would hope. Troubles with various file formats, internet and server delays, and formatting everything for the wiki have caused more trouble than was expected. Next time, we're going to all need to make sure that everything is in a few days prior so the Wiki guy has time to edit, send the wiki to everyone for approval, and see what problems might occur. As such, four valuable movies that would have been placed on the wiki had to be omitted. Someone also erased all the information on how to edit the wiki and wrote "hey". This was not helpful.

Work Proposal

The disassembly of the power washer has gone reasonably smooth, with no major problems. This is due to the well-detailed Work Proposal submitted in gate one. We have been able to disassemble the power washer almost entirely with the tools listed, and have taken an extensive amount of photographs for documentation. Our group has stayed on schedule and has completed the task within the two to six hour time prediction stated in our Work Proposal (approximately two hours). As our work proposal predicted we ran into complications, however all but one was solved:

1. On the outside of the compressor shell one of the size 5 Allen bolts became slightly stripped due to extreme tightness. To solve this we used an overly large Allen wrench.

2. On the pressure gun two screws could not be removed initially. A new size 1 Phillips head screw had to be used.

3. Initially the group did not have the proper tools to remove the crank shaft. A bearing press was found and used to press out the shaft.

4. On the pneumatic system many of the bolts could not be removed. This is because our group does not have the professional equipment necessary.

Challenge 4 remains the only unsolved predicament. We do not have the time or money to get the equipment necessary to successfully remove those bolts. As such, we’ve left the pneumatic system intact.

Preliminary Project Review

For the Preliminary Project Review the Causes for Corrective Action was originally assigned to Cody Boppert, and the Product Dissection Plan was assigned to Chris Kujawinski. From the information we gathered about each other from Gate one, we adjusted who was assigned to each task. The Causes for Corrective action was reassigned to Tom Matikainen. Because Tom worked directly on the gantt chart, it was decided that he would best understand how true we have been to the original assignments and timeline. Chris Kujawinski was aided by Cody Boppert, Matt Fasoldt, and Chris Wojciechowski in his work for the Product Dissection Plan. These members worked most closely with the physical dissection of the power washer. The time restrictions set by our gantt chart were slightly modified due to scheduling conflicts. Both deadlines set were set back by two days, still multiple days before the class deadline.

Product Disection Plan

Video Links

[1] - The start of the removal of the front plate

[2] - The start of the removal of the right plate

[3] - The creation of more torque with the use of an open ended tool

[4] - The pistons moving from below

[5] - The pistons moving from above

Pressure Washer Gun Dissection

1. Removal of the Gun Handle:

a. Using a size 1 Phillips screwdriver, remove the 8 screws holding together the plastic to the gun handle.

b. After the screws are removed remove the plastic handle casing, exposing the water barrel system composed of 3 different barrel shafts through which the water was to be released.

2. Removal of Barrel Nozzle:

a. Using a 7/8” crescent wrench to hold the shaft so it doesn’t rotate, use a 7/8”s socket wrench to remove the nozzle from the water barrel system.

3. Removal of the first barrel Connector Piece:

a. Unscrew the shaft barrel connector from the water pressure adjuster piece.

4. Removal of the Middle Barrel:

a. Using a vice grip and an 11/16”crescent wrench we removed the barrel shaft from the trigger valve system which from which the plastic handle sheath slides off, and the pressure adjuster plastic to slide off the barrel shaft

5. Removal of the hose to Pneumatic Trigger Water Barrel:

a. We used two 11/16” crescent wrenches, one to prevent the barrel from rotating, and one to remove the hose to gun connecter shaft from the trigger valve system.

--For more information on the gun dissection please see Grp27: Appendix II--

Hose Dissection

1. End of Hose:

a. Using a vice grip to properly grip the hose and a 15/16” crescent wrench we removed the metal end of the hose, which the gun connected too.

b. The other end of the hose is inserted in to the hose and most likely glued and could not be removed.

--For more information on the Host dissection please see Grp27: Appendix II--

Pneumatic System Dissection

1. Removal of the Gaskets

a. Using your finger or a small dull screw river of any kind take out the gasket system in the cylinders located on the bottom face.

2. Removal of Left Face Bolts:

a. Using a 3/4” crescent wrench rotate the bolts counter clockwise and remove them.

3. Removal of the Air Filter:

a. Looking at the top face, approximately an inch from the black spin handle. Using a 1-1/4” crescent wrench, rotate the bolt counter clockwise to loosen.

b. Remove screen from top of nut and take apart nut and bolt threading.

--For more information on the pneumatic system dissection please see Grp27: Appendix III--

Compressor Dissection

1. Removal of the Compressor Fluid:

a. Using your hand rotate the top red and black plastic bolt, counter clockwise to loosen and remove.

b. Take the compressor in hands, and out of threaded hole where black and red bolt was, pour the fluid out into a desired container.

2. Removal of the Front Plate:

a. Using a metric, size 5, allen wrench, rotate the bolt counter clockwise, and remove the 6 bolts that hold the front plate to the compressor.

b. Take off the front plate and remove the gasket from the back.

c. Using 11/16", and 13/16" sockets respectively as well as a ratchet, remove both the metal and plastic bolts that are in the front plate of the compressor by rotating the ratchet counter clockwise.

d. Using your hand remove the gasket located underneath the plastic 13/16" bolt.

3. Removal of the Right Plate:

a. Using a metric size 5 allen wrench, remove the 4 bolts holding the right side plate on the compressor. Rotate the bolt counter clockwise to loosen the bolts.

b. Flip the right plate upside down and look at the part of the face that was inside the compressor. Using a flat head screw driver get underneath the gasket and remove it from the plate.

4. Removal of the Left Plate:

a. Using a metric size 5 allen wrench remove the four bolts holding on the left side plate (1).

b. Flip the plate over and remove the circular gasket around the circle on the back of the plate as well the gasket inside the circular shaft area.

c. Using a pair of pliers and a flat head screw driver, pry open the c clip on the end of the shaft sticking out of the left side of the compressor

5. Removal of the Pneumatic System on back side of compressor:

a. Locate the Pneumatic System (brass) on the back of the compressor

b. Locate the 8 black bolts located on the top face of the compressor in the middle of the top face.

c. Using a metric size 5 allen wrench turn the bolts clockwise and remove them as well as their washers from their places on the top face.

d. While holding the system so its top is facing to the side, not up towards the ceiling, pull the pneumatic system away from the compressor.

6. Removal of the Shaft:

a. Using a bearing press, take the plate of the press and align it with the screw holes on the left side of the compressor.

b. Install bolts going through the plate of the bearing press into the threaded holes of the left side of the compressor. Tighten the bolts until snug to the plate

c. Install the large threaded rod included in the bearing kit into its respected hole in the middle of the bearing plate. Hand screw the rod into the threaded hole making sure that it is correctly in place. When correctly in place screw until the rod becomes tight.

d. Take a socket that fits on the hexagon shaped end of the large rod (the unthreaded side that you did not screw in to the plate) and place the socket on the end of the rod. Using a ratchet attached to the socket rotate the rod clockwise and start to tighten the rod into the plate. This will cause the rod to push on the shaft and remove it from the shaft channel.

e. As the shaft is removed, the piston connecting rods are displaced from the crank journals. The connecting rods have to be aligned with the shape of the crank journals in order for the shaft to move through each of the connecting rods (2).

f. As the shaft is pushed through, the bearing on the right side will come out as well.

7. Removal of the Pistons:

a. With the shaft out of the compressor flip the compressor on its front side so the pistons are facing up.

b. Find a smaller size punch that fits in the divots on the tops of the pistons. Using the punch and a hammer, hold the punch on the divot of the piston, and using a downward swing of the hammer strike the punch and dislodge the piston from its white ceramic holder and piston channel it is held into.

c. With the piston out take the punch and punch out the middle pin holding the piston with the journal connector.

8. Removal of the Bearing on the Left Side:

a. Using the bearing plate and rod still in tact on the right side unscrew the rod so it is half way in the compressor shell. Take an object such as an item in your puller kit, if you have one or a socket big enough to lie around the hard metal outside of the bearing.

b. Take that item and place it on the inside of the compressor with the item laying on the hard outer edge of the bearing.

c. Using the ratchet and socket from Direction #6, begin to screw the rod back down clockwise so the rod pushes on the insert laying on the outer edge of the bearing.

d. As the rod pushes on the item insert, the insert will push on the bearing which, in turn will move out of the channel.

--For more information on the compressor dissection please see Grp27: Appendix I--

@@ Line 76: / Line 76: @@
 '''Design Revisions'''
-I. No Alan (hex) bolts. Easily removed
+'''I. No Alan (hex) bolts. Easily removed'''
 <nowiki>
         There were many Alan bolts that we had to remove during the dissection. Unfortunately, a select few of these Alan bolts and Phillips heads stripped. The nature of the shape of the hexagonal Alan key makes it susceptible to stripping. The hexagon is close in shape to a circle, and it does not take much stripping before the Alan key is no longer able to “catch” inside the hex bolt. The stripping is caused by the high moment resistance the bolts give to being loosened, as they are tightly screwed into place.
@@ Line 85: / Line 86: @@
 </nowiki>
-II. Push start instead of pull start
+'''II. Push start instead of pull start'''
 <nowiki>
@@ Line 95: / Line 96: @@
 </nowiki>
-III. Ability to access other water supplies
+'''III. Ability to access other water supplies'''
 <nowiki>

Group 27 - Pressure Washer

Revision as of 23:56, 7 December 2009

Gate 3

Gate 2

Product Disection Plan

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