Group 3 - Skil Circular Saw - Revision history

MAE277 03 09: /* Management Proposal */

2009-12-15T20:09:02Z

Management Proposal

MAE277 03 09: /* Executive Summary */

2009-12-15T14:18:05Z

Executive Summary

MAE277 03 09: /* Product Reassembly Plan */

2009-12-07T20:40:52Z

Product Reassembly Plan

MAE277 03 09: /* Product Reassembly Plan */

2009-12-07T20:28:55Z

Product Reassembly Plan

MAE277 03 09: /* Product Reassembly Plan */

2009-12-07T20:24:41Z

Product Reassembly Plan

MAE277 03 09: /* Product Reassembly Plan */

2009-12-07T20:14:37Z

Product Reassembly Plan

MAE277 03 09: /* Product Reassembly Plan */

2009-12-07T19:52:17Z

Product Reassembly Plan

MAE277 03 09 at 19:51, 7 December 2009

2009-12-07T19:51:29Z

MAE277 03 09 at 19:48, 7 December 2009

2009-12-07T19:48:06Z

MAE277 03 09: /* Component Summary */

2009-11-30T20:22:41Z

Component Summary

@@ Line 64: / Line 64: @@
 ==='''Management Proposal '''===
 ----
-Group meetings will take place immediately following class on Mondays. The group will commence in the lecture hall and move to an appropriate area depending on the task at hand. Group meetings will focus on completing portions of tasks, and adjusting the completion timeline accordingly. All group members will put forth equal contributions to any/all reports necessary for the duration of the project.
+Our Management proposal can be viewed [[Group_3_-_Skil_Circular_Saw/Management_Proposal|here]]
-−
-The following is an estimation of when tasks/sub-tasks will begin, and the amount of time each task will take. This allows the group to meet project deadlines, while providing a sensible duration.  The dates projected allow for reasonable adjustments when applicable.
-−
-[[Image:Gantt Chart.jpg | Table 3.2.1: Gantt Chart ]]
-Table 3.2.1 - Gantt Chart
-−
-{| {{table}}
-| align="center" style="background:#f0f0f0;"|'''Tasks'''
-| align="center" style="background:#f0f0f0;"|'''Sub-Tasks'''
-| align="center" style="background:#f0f0f0;"|'''Start Date'''
-| align="center" style="background:#f0f0f0;"|'''Duration (Days)'''
-|-
-| Request for Proposal||Initial Product Assessment||10/5/09||3
-|-
-| ||Work Proposal||10/5/09||2
-|-
-| ||Management Proposal||10/5/09||4
-|-
-| Preliminary Project Review||Product Dissection Plan||10/9/09||4
-|-
-| ||Product Dissection||10/13/09||3
-|-
-| ||Causes for Corrective Action||10/16/09||11
-|-
-| Coordination Review||Component Summary||10/29/09||8
-|-
-| ||Design Revisions||11/4/09||5
-|-
-| ||Solid Modeled Assembly||11/8/09||10
-|-
-| ||Engineering Analysis||11/12/09||9
-|-
-| Critical Project Review||Product Re-assembly Plan||11/21/09||8
-|-
-| ||Product Re-assembly||11/30/09||5
-|-
-| Delivery||Complete Revisions||12/4/09||7
-|-
-| ||Submit Final Report||12/11/09||N/A
-|}
-Table 3.2.2 - Timeline Estimates
 ==='''Initial Product Assessment '''===

← Older revision		Revision as of 14:18, 15 December 2009
Line 2:		Line 2:

	=='''Executive Summary'''==		=='''Executive Summary'''==
		+
		+	The task of our group is to reverse engineer a Circular Saw manufactured by Skil. To begin this process, we first analyzed how the saw performs its task, more specifically, how the energy is transferred from electrical energy from the wall, to the mechanical energy used to cut the material. After this, we then began to disassemble the saw, documenting the whole procedure and taking note of each component as it was removed. After the saw was completely broken down to the level of our ability, each of the components were distributed to team members and individually analyzed, to determine the process they were manufactured by, why that process was chosen, and the purpose of each part. This required each member to have a thorough understanding of manufacturing processes and the overall operation of the saw. After the in-depth analysis was performed, the saw was reassembled. Although all the components were put together in their respective places, the saw would not run again due to a faulty component that will have to be replaced. The Skil circular saw is a complex piece of machinery that can only be truly understood once it has been taken apart.

	=='''Group Members'''==		=='''Group Members'''==

@@ Line 339: / Line 339: @@
 Our group met to complete the reassembly process on Monday the 7th of December. Each member was tasked with the partial reassembly of  a section of the device. Once we were all finished with our individual parts, we proceeded to put them all together; naturally, some parts had to be left to be assembled individually. The final assembly process went as planned, with the entire event spanning about 40 minutes. During the later stages of the process, we identified a connection issue with the carbon brushes. We tried to the best of our effort to obtain a proper connection for the severed wires and the carbon piece; the machine was tested several times to no avail. Upon closer inspection of the issue, our group understood that obtaining a proper connection between the wires and the carbon block was beyond our abilities.
-Unfortunately, the saw does not work like it did when we received it at the beginning of the semester.  We have determined that the problem is that for the carbon brushes, there is a torn wire that should be embedded into the carbon block, and it is beyond our ability to repair.  A way to correct this would be to order part # 810 from Skil Tools, which you can do through their catalog, and to replace the broken components.
+Unfortunately, the saw does not work like it did when we received it at the beginning of the semester.  We have determined that the problem is that for the carbon brushes, there is a torn wire that should be embedded into the carbon block, and it is beyond our ability to repair.  We attempted to affix the wire to the carbon with electrical tape, however that proved to be futile.  A way to correct this would be to order part # 810 from Skil Tools, which you can do through their catalog, and to replace the broken components.
 The disassembly and reassembly processes were very similar. To reassemble the saw, pliers were not required because the components easily pushed into place, thus they did not pliers to remove.  We used the disassembly process as a guideline to follow in reverse order, which was very useful to us and cut down on the time required and lowered our frustration.  We were able to put the saw back together completely, even though the one set of components were broken, they still did not prevent themselves from fitting into their proper locations.

@@ Line 343: / Line 343: @@
 The disassembly and reassembly processes were very similar. To reassemble the saw, pliers were not required because the components easily pushed into place, thus they did not pliers to remove.  We used the disassembly process as a guideline to follow in reverse order, which was very useful to us and cut down on the time required and lowered our frustration.  We were able to put the saw back together completely, even though the one set of components were broken, they still did not prevent themselves from fitting into their proper locations.
-We would recommend to make the wires on the carbon brush set stronger, because they were broken when we took apart the saw, whether it was due to method we took it apart, or due to some malfunction while running the saw.  We also recommend that the wires leading from the trigger to the motor be longer, because during the reassembly process, it was fairly difficult to slide the stater all the way to the back of the plastic housing.
+We would recommend to make the wires on the carbon brush set stronger, because they were broken when we took apart the saw, whether it was due to method we took it apart, or due to some malfunction while running the saw, as it was sparking very bright when we ran it at the beginning of the semester, so it may have already been severed and was just jumping the gap.  We also recommend that the wires leading from the trigger to the motor be longer, because during the reassembly process, it was fairly difficult to slide the stater all the way to the back of the plastic housing.
 {| {{table frame=1}}

@@ Line 337: / Line 337: @@
 =='''Product Reassembly Plan'''==
-Our group met to complete the reassembly process on Monday the 7th of December. Each member was tasked with the partial reassembly of  a section of the device. Once we were all finished with our
+Our group met to complete the reassembly process on Monday the 7th of December. Each member was tasked with the partial reassembly of  a section of the device. Once we were all finished with our individual parts, we proceeded to put them all together; naturally, some parts had to be left to be assembled individually. The final assembly process went as planned, with the entire event spanning about 40 minutes. During the later stages of the process, we identified a connection issue with the carbon brushes. We tried to the best of our effort to obtain a proper connection for the severed wires and the carbon piece; the machine was tested several times to no avail. Upon closer inspection of the issue, our group understood that obtaining a proper connection between the wires and the carbon block was beyond our abilities.
-Unfortunately, the saw does not work like it did when we received it at the beginning of the semester.  We have determined that the problem is that for the carbon brushes, there is a torn wire that should be embedded into the carbon black, and it is beyond our ability to repair.  A way to correct this would be to order part # 810 from Skil Tools, which you can do through their catalog, and to replace the broken components.
+Unfortunately, the saw does not work like it did when we received it at the beginning of the semester.  We have determined that the problem is that for the carbon brushes, there is a torn wire that should be embedded into the carbon block, and it is beyond our ability to repair.  A way to correct this would be to order part # 810 from Skil Tools, which you can do through their catalog, and to replace the broken components.
 The disassembly and reassembly processes were very similar. To reassemble the saw, pliers were not required because the components easily pushed into place, thus they did not pliers to remove.  We used the disassembly process as a guideline to follow in reverse order, which was very useful to us and cut down on the time required and lowered our frustration.  We were able to put the saw back together completely, even though the one set of components were broken, they still did not prevent themselves from fitting into their proper locations.

@@ Line 358: / Line 358: @@
+Note: Numbers in procedure correspond to part numbers on the schematic above in the Product Dissection Plan section.
 Note: Numbers in procedure correspond to part numbers on the schematic above.
 {| {{table  border=1}}
 |+ '''Procedure''':

← Older revision		Revision as of 19:51, 7 December 2009
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	Our group met to complete the reassembly process on Monday the 7th of December. Each member was tasked with the partial reassembly of a section of the device. Once we were all		Our group met to complete the reassembly process on Monday the 7th of December. Each member was tasked with the partial reassembly of a section of the device. Once we were all
		+
		+
		+	{\| {{table frame=1}}
		+	! align="left" style="background:#f0f0f0;"\|Tools Required:
		+	\|-
		+	\|T20 & T30 Torx bit
		+	\|-
		+	\|Provided blade wrench (#651)
		+	\|}
		+
		+
		+	Difficulty is defined by the following scale (1-5) where:
		+
		+	1 - Determining the approach and performing the action require little to no thought, and uses basic or no tools.
		+
		+	3 - Part may be reluctant to be reinserted or may require a specific procedure to be reinserted.
		+
		+	5 - Takes several minutes to develop a procedure to perform the action, the action takes some time, and complex tools may be required. The procedure to reattach the part may not be intuitive, or at times, frustrating.
		+

← Older revision		Revision as of 19:48, 7 December 2009
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	*Discussion:		*Discussion:
	**The amount of torque computed is the minimum amount that must be provided by the blade nut/bolt. The assumptions that were made were used to analyze a very strong piece of wood being cut by the saw, which would be operating at full output. Friction between the saw blade and bolt could be neglected because in comparison to the other forces acting on the blade, the friction would be small and therefore, the torque created would be negligible.		**The amount of torque computed is the minimum amount that must be provided by the blade nut/bolt. The assumptions that were made were used to analyze a very strong piece of wood being cut by the saw, which would be operating at full output. Friction between the saw blade and bolt could be neglected because in comparison to the other forces acting on the blade, the friction would be small and therefore, the torque created would be negligible.
		+
		+	=='''Product Reassembly Plan'''==
		+
		+	Our group met to complete the reassembly process on Monday the 7th of December. Each member was tasked with the partial reassembly of a section of the device. Once we were all
		+
		+
		+	Note: Numbers in procedure correspond to part numbers on the schematic above.
		+	{\| {{table border=1}}
		+	\|+ '''Procedure''':
		+	\| align="center" style="background:#f0f0f0;"\|'''Step #'''
		+	\| align="center" style="background:#f0f0f0;"\|'''Description'''
		+	\| align="center" style="background:#f0f0f0;"\|'''Difficulty'''
		+	\|-
		+	\| 1\|\| Insert gear (#825) into protective cover (#24)\|\|1
		+	\|-
		+	\| 2\|\| Thread trigger wires (#30 & #31) through hole in housing (#1) and attach to back of the field\|\|5
		+	\|-
		+	\| 3\|\| T20 Torx bit to attach outer section of electric motor field (#2) to motor housing (#1) using long screws (#39)\|\|1
		+	\|-
		+	\| 4\|\| Attach motor brushes (#810) to the field through the back of the housing\|\|3
		+	\|-
		+	\| 5\|\| Insert electric motor armature (#3) into the shaft in the back of the housing (#1)\|\|2
		+	\|-
		+	\| 6\|\| Reattach the safety cover (#32) and the protective cover (#24) by sliding slots into each other\|\|1
		+	\|-
		+	\| 7\|\| Screw back on depth switch nut by hand and slide on the depth switch (#846) and affix in place with snap ring\|\|1
		+	\|-
		+	\| 8\|\| Reattach blade guard spring (#33) to protective cover, making sure the hook on the spring is secure around the notch(#24)\|\|1
		+	\|-
		+	\| 9\|\| T30 Torx bit on final bolt (#51) to reattach blade cover stopper (#49)\|\|1
		+	\|-
		+	\| 10\|\| T20 Torx bit on 7 bolts (#27) to attach blade covers together (#24 & #32)\|\|3
		+	\|-
		+	\| 11\|\| Use provided Blade Wrench (#651) to screw in bolt (#52) that retains blade along with 2 washers (#28)\|\|2
		+	\|-
		+	\| 12\|\| Insert trigger assembly (#4) into plastic handle components (#837)\|\|1
		+	\|-
		+	\| 13\|\| Reattach plastic handle components (#837) to the housing (#1)\|\|2
		+	\|-
		+	\| 14\|\| 20 bit torque nut on 8 bolts (#19) to attach plastic cover (#29) to rear of the housing (#1)\|\|2
		+	\|-
		+	\| 15\|\| Reattach wing nut (#42) on side to prevent foot (#40) from rotating\|\|1
		+	\|-
		+	\|}

@@ Line 261: / Line 261: @@
 |26 (Bearing Assembly)||Aluminum - Easy to shape. Light weight. Durable enough for intended use.||No external forces applied as component is purely manufactured by casting.|| Manufactured by casting. Outer cylindrical shell and inner cylindrical shell cast separately. Lubrication applied to reduce friction and increase longevity.|| Cylindrical shape necessary to house shaft assembly.||Component is purely functional. Due to the location of the component, no cosmetic manufacturing need be done.  Assembly manufactured purely to satisfy the functional requirement.||Establishing a scale of 1 -5; 1 corresponding to a component with no moving parts and possessing a very simple shape, and 5 corresponding to a component with multiple moving parts that interact with each other, and possessing a very complex shape, the bearing would attain a value of 3.5 due to the integration of the ball bearings, and the precision required during manufacturing.||[http://www.flickr.com/photos/45079311@N04/4145848509/in/photostream/ Bearing1] [http://www.flickr.com/photos/45079311@N04/4146608014/in/photostream/ Bearing2]
 |-
-|3 (Motor)||Shaft, stator and fan are made of Steel, because it is strong enough to serve as a secure shaft, and cheap enough to keep prices low. Wires are made of copper, a cheap and efficient material to conduct electricity.||Significant torque is applied to the shaft from the magnetic field created by the stators. The shaft is able to convert this magnetic field force into shaft work in the order of 2.3 HP. It is possible that there are also shearing forces from the bearings and the connections at the front end of the shaft.||The shaft was cut down on a lathe and the star shape on the front end is forged, The wires are drawn through wire drawing. The fan was stamped out of sheet metal and bent into the desired place.||The part is made the way it is because it is the most efficient way to transmit torque from the magnetic field forces created by the stators.||Functional: Converts magnetic field forces into shaft work to rotate the blade.||Very complex since the coil must have a certain number of wires in it and shaped in a specific way. The placement of the stator and the fan as well as their dimensions are important to the proper functioning of the device.||[http://i82.photobucket.com/albums/j255/siegfried11/P0911301713457.jpg?t=1259602574 Part 3]
+|3 (Motor)||Shaft, stator and fan are made of Steel, because it is strong enough to serve as a secure shaft, and cheap enough to keep prices low. Wires are made of copper, a cheap and efficient material to conduct electricity.||Significant torque is applied to the shaft from the magnetic field created by the stators. The shaft is able to convert this magnetic field force into shaft work in the order of 2.3 HP. It is possible that there are also shearing forces from the bearings and the connections at the front end of the shaft.||The shaft was cut down on a lathe and the star shape on the front end is forged, The wires are drawn through wire drawing. The fan was stamped out of sheet metal and bent into the desired place.||The part is made the way it is because it is the most efficient way to transmit torque from the magnetic field forces created by the stators.||Functional: The shaft and stator work together to convert magnetic field forces into shaft work to rotate the blade. The copper coil serves to provide this magnetic field and the fan cools the housing to prevent overheating from long service times.||Very complex since the coil must have a certain number of wires in it and shaped in a specific way. The placement of the stator and the fan as well as their dimensions are important to the proper functioning of the device.||[http://i82.photobucket.com/albums/j255/siegfried11/P0911301713457.jpg?t=1259602574 Part 3]
 |-
 |825(Pinion Shaft)||Steel, because it is strong enough to hold parts securely, and cheap enough to keep prices low.||The force required to keep the forge and extrude the shaft.||Steel extruded, threaded on a lathe, and having both ends cut and head forged.||Part has a Torx and a flathead socket to allow it to be removed easily.||Functional: Holds the blade onto place.||Simple as it is basically a shaft with an end made as a gear to receive the blade torque.||[http://i82.photobucket.com/albums/j255/siegfried11/P0911301714584.jpg?t=1259604572 Part 825]