Group 5 - Two Power Sanders

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Ryobi Corner Sander

Battery Powered Ryobi Corner Sander

Introduction

For the MAE 277 reverse engineering project, our group was given two electric powered RYOBI corner sanders (Model #’s P400 & CFS1502). One of the sanders is powered by an electric cord and the other is battery-powered. Throughout the semester, we will be dissecting and analyzing the components that make these two products work. We will then compare the different results for the two sanders to figure out which one is more efficient than the other.

Gate 1

Work proposal

Management proposal

Product assessment

Gate 2

Causes of Corrective Action

Product Dissection Plan

Analysis

Gate 3

Component Summary

Design Revisions

Recommend at least 3 design changes for the product at the component level, including features you would change or eliminate and components you would combine or eliminate. These changes should improve the product by reducing its cost/weight/maintenance or enhancing its functionality/ergonomics/reliability. Keep in mind the products target audience and price point when making changes. Publish these results to your group’s wiki.

Change the design of the outer shell - Since the sander will be pushed in a horizontal direction to the surface, the outer shell should be at an angle instead of going straight down on the plane. It would make it easier to maneuver and it would be more comfortable for long term use. It is the same reason that when a person is using a saw they hold it at a 45 degree angle when the direction of the cut is going straight down. It makes it easier and more comfortable to cut.
Change the location of the on/off switch on battery powered sander - When holding the battery powered sander the user’s thumb sometimes rubs up against on/off switch causing the sander to turn off during use. The switch can be placed an inch lower than where it is right now so it is still easy to access, but out of the way enough so it won’t accidentally get hit.
A longer cord for the AC sander - The cord that comes with the sander is about 9 feet long. If using this sander for large projects often times there are large pieces of wood. This can become a problem and extension cords would be needed. A 15 foot cord would be long enough because there are not many pieces of wood that are longer than that, and it would leave room for an outlet that is far away.

Solid Modeled Assembly

Assembly video

The CAD package I choose to use is Professional Engineer (Pro/E) by PTC. I choose this CAD package because it has simple modeling features and available tutorials.

[1]

When redesigning components for the solid modeling portion of the project we decided to create a hybrid of both sanders. Both sanders had features that we wanted to have in variant design. We liked the simplicity of the inner components (motor/switch/leads) of the P400 sander because they we neatly put together and more user friendly. The P400 also had a nice battery operated power system that we wanted include in our design which allows the sander to be more portable. We also liked the vacuum system in the CFS1502 which gives our sander a dust management capability. The CFS1502 also has better ergonomics with its “mouse” type control. When we put all these functions into one design we may have came up with a totally new product but in reality we only change a couple components:

Components #1 & #2:

[2] [3]

The right and left outer casings were redesigned to allow the addition of features such as the vacuum system.

Component #3

[4]

While dissecting the sanders we noticed that the sand paper Velcro pad and housing were separate components. We decided to combine these components into one which eliminates extra fasteners, and one manufacturing process. This will lower the cost of manufacturing the sander and keep it competitive in the market.

Assembly:

[5]

Aside from those components the rest of the sander is basically borrowed parts from the other two sanders. The battery/motor/switch system is borrowed from the P400, and the vacuum/ bearing spindle assembly is borrowed from the CFS1502. Altogether the consumer is getting the best of both worlds with our variant design.

Engineering Analysis

Problem Statement: If you use a 400 ft extension cord for the power sander, will that 400 foot extension cord be enough to power the Ryobi power sander.

Diagram: [6]

Assumptions:

For the sander to run it needs 120 volts
The sander will not be able to run with 60 volts supplied from the cord
The current for the sander to run is 1.2 A
The radius of the extension cord is 1.5 mm
The extension cord is made out of copper
The temperature is 20 degrees Celsius
The resistivity is 1.62 x 10-8
The cord is made out of copper

Governing Equations:

R = V/i
R = (resistivity) * (L/A)
A = π*r^2

Solution:

R = V/i R = 60/1.2 = 50 ohms R = (resistivity) * (L/A) A = 3.14 * .00152 50 = (1.62 x 10-8) *(L/7.07x10-6) L = 71,590 ft

400ft < 71,590ft So the 400 ft extension cord would be enough to power the Ryobi power sander.

Discussion:

The 400 foot extension cord would be able to deliver enough power to the power sander. The 400 foot extension cord won’t be enough because it would take 71,590 feet of extension cord until the power sander wouldn’t be able to have enough power to run. This is true only under the assumption that the power sander would not work at 60 volts. However any higher voltage that the sander would not work at would mean the length of the cord would be less than 71,590 ft.

Gate 4

Assembly

RYOBI Battery-Powered Corner Sander

Step	Description	Easiness	Tools Used	Pictures
1	Place the electric motor and switch assembly into the housing so that the spindle is placed into the lube. This part is fitted into the casing. The wires should be tucked into the outer parts of the housing so they will not be pinched when it is put together.	1	Hands	Casing and Motor
2	Place the black switch in it\'s fitted housing next to the motor. Then place the yellow on/off switch over the black one.	1	Hands	Casing and Motor
3	Place the small metal clip against the yellow switch to stabalize the switch.	3	Hands	Metal Clip
4	Place the gears and bearing with counterweight into its fitted spot in the housing. The gears should be able to now spin the spindle.	1	Hands	Casing and Motor
5	Place the two white connectors into the housing. The smaller one fits in below the switch assembly. If looking at the sander with the motor to the top right, the larger connector will be placed about an inch to the left of the gears in it\'s fitted spot.	1	Hands	Casing and Motor
6	Slide the other casing onto the casing with the motor, gears, and switch assembly. It should match up so that connectors go into their fitted spots. The connectors should now be seen on the botton of the sander.	2	Hands	Casing and Motor
7	There are eleven Phillips head #2 screws that need to be screwed onto the outer casing. There are designated holes for the screws, and they are the only holes on the sander.	2	Phillips head #2 screw-driver	Casing and Motor
8	This is the orange piece that can be taken out by hand. It is located along the handle next to the rubber grip	1	Hands	Casing and Motor
9	Snap the velcro pad housing onto the bottom of the sander. It snaps on using the connectors.	1	Hands	Casing and Motor
10	There are five phillips head #2 screws that need to screw the sand-paper velcro pad onto the sander.	2	Phillips head #2 screw-driver	Casing and Motor

RYOBI Corner Sander

Step	Description	Easiness	Tools Used	Pictures
1	Slide the field assembly over the armeture. The wires for the switch should be on the opposite side of the vacuum fan as seen in the picture.	1	Hands
2	Attach the switch to the field assembly. This is done by connecting it to the fitted connector of the red wire.	1	Hands
3	Connect the black wire coming from the power supply cord to the switch.	1	Hands
4	Place one brush into the connector coming from the white cord of the power supply. Place the other brush into the connector coming from the black cord of the field assembly.	1	Hands
5	Place the two white connectors into the housing. The smaller one fits in below the switch assembly. If looking at the sander with the motor to the top right, the larger connector will be placed about an inch to the left of the gears in it\'s fitted spot.	1	Hands
6	Everything assembled thus far will fit onto the casing. The field assembly has a fitted spot in the center of the casing, everything else attached dwill fall into it\'s fitted spot.	1	Hands
7	The orange on/off switch lays in next to the switch assembly	1	Hands
8	The black fan baffle fits in over the sand vacuum. The curved edges will fit onto the housing properly.	1	Hands
9	Place the two white connectors into the housing. The smaller one fits in below the switch assembly. If looking at the sander with the motor to the top right, the larger connector will be placed about an half an inch to the left of the field assembly in it\'s fitted spot.	1	Hands
10	Place the second part of the housing onto the connectors. Wires must be placed in designated areas. There are teeth that will catch the wires to keep them in place.	4	Hands
11	Screw the two cord clamp screws over the cord where it meets the sander.	2	Phillips Head #2 screw-driver
12	Screw in both of the external screws to connect both casings. These screws are located underneath where the grip will be.	2	Phillips Head #2 screw-driver
13	Place the grip on top of the sander. Fasten the three top cover screws.	2	Phillips Head #2 screw-driver
14	Place the velcro pad housing onto the bottom of the sander and use the 4 velcro pad housing screws to fasten it.	2	Phillips Head #2 screw-driver
15	Place the velcro pad onto the velcro pad housing and use 5 of the velcro pad housing screws to fasten it onto the velcro pad housing.	2	Phillips Head #2 screw-driver
16	Fit the vacuum bag over the vacuum exhaust coming out the back of the sander as seen in the picture.	1	Hands

References

Ryobi Corner Cat Power Sander Parts (model #CFS1502)

@@ Line 31: / Line 31: @@
+=== [[Design Revisions]] ===
-For both sanders, different materials were selected for different components. ABS plastics were used to provide durability and strength for internal components such as the on/off switch and the Velcro pad housing for the sanders. Various amounts of steel and metal were used for different purposes. Metal associated with electrical flow within the sanders helped to distribute electricity from the power source. This mainly involves the switch/motor assembly where electrical power is centralized. The composition of this assembly includes metal for the leads, metal for the motor, and a mixture of ABS plastic, copper and metal. Different types of steels were used for various screws to help retain the assembly of both sanders. Rubber-based materials were used mainly around areas of electrical power. The power cord was encased in a rubber-based material to provide safety from dangers such as electrical shock. Rubber was also used on the handle so that when using the sanders, there was proper control toward tasks at hand. Malleable plastics were used for the cushion supports which helped keep the Velcro pad housing attached to the base of the sanders. As for the Velcro pad, Velcro helps to ensure necessary adhesiveness to keep the sand paper firmly attached to the sander. Finally, Polystyrene Plastic was used for the body casings of both sanders. This type of plastic is needed to provide necessary durability and strength. This is needed so that the sanders can withstand excessive force as well as keeping a boundary between the user and the internal components.
-The forces that are involved in this system are electrical forces and applied forces. The applied forces include compressive force from the force applied from the user and tensile force from the screws holding the casing together. There is also a frictional force acting on the system mainly at the base of the sander between the Velcro and the sand paper. Finally there is a centripetal force acting on counterweight that provides for the oscillating motion.
-Material choice does affect the manufacturing process. Since different types of materials are used for different components, there is not just one simple manufacturing process. For example, various plastics of these sanders are processed through injection molding whereas thread rolling is used for screws. Each process is designed specifically to fit the needs of each part. While ABS plastics were used for internal components for each sander for slight flexibility, the Polystyrene Plastic was used for the outer body casing for no flexibility. Different types of manufacturing processes are necessary to build these sanders.
-Shape is also affects the manufacturing processes of each sander. Each part needs to be able to fit within both sanders. The outer body casing needs to encase all the internal components as well as provide a handle and grip for each sander. The parts are made the way they are primarily because of size constraints. Parts can be functional but if they can’t fit into the product then the whole product is not functional. Shape is an important aspect for both of these sanders.
-Basically, each internal component mainly serves a functional purpose. Only components that can be seen externally provide both functional and cosmetic purposes. The reason for these cosmetic purposes is most likely due to appeal to the consumer.
-When considering different materials manufactured by different processes, shape and size constraints, and other actions involved, the complexity of each component is relatively difficult. Each component’s level of difficulty involves basically the same procedures. Obtaining the material leads to the planning and manufacturing of the material where size and shape constraints are taken into consideration.
-=== Design Revisions ===
 Recommend at least 3 design changes for the product at the component level, including features you
@@ Line 95: / Line 80: @@
 Aside from those components the rest of the sander is basically borrowed parts from the other two sanders. The battery/motor/switch system is borrowed from the P400, and the vacuum/ bearing spindle assembly is borrowed from the CFS1502. Altogether the consumer is getting the best of both worlds with our variant design.
-=== Engineering Analysis ===
+=== [[Engineering Analysis]] ===
 Problem Statement: