American DJ Aftershock Party Light - Revision history

Mhaile at 05:49, 26 March 2007

2007-03-26T05:49:44Z

Mhaile at 05:46, 26 March 2007

2007-03-26T05:46:47Z

Mhaile at 05:44, 26 March 2007

2007-03-26T05:44:20Z

Mhaile at 05:43, 26 March 2007

2007-03-26T05:43:35Z

Mhaile at 05:43, 26 March 2007

2007-03-26T05:43:10Z

Mhaile at 05:42, 26 March 2007

2007-03-26T05:42:32Z

Mhaile at 05:39, 26 March 2007

2007-03-26T05:39:48Z

Mhaile at 05:38, 26 March 2007

2007-03-26T05:38:28Z

Mhaile at 05:37, 26 March 2007

2007-03-26T05:37:12Z

Mhaile at 05:36, 26 March 2007

2007-03-26T05:36:43Z

@@ Line 212: / Line 212: @@
 | align="center"|The diaphragm size and rubber stiffness could be changed, allowing for different diaphragm geometries.  However, it makes no sense to change the diaphragm given the robust nature of the design in resisting cyclic failure.  The diaphragm is extremely well suited to this particular application.
 |-
 |}
-{| align="center"
+{|
-|+[[Image:aftershock.png|right|thumb|300px|Figure 6: Front, Right, Isometric Views for the Shake Table Assembly]]
+|align="left"|[[Image:ForceVTime.JPG|right|thumb|300px|Figure 5: Force vs. Time Plot]]
 |}
 {| align="center"
 |+<embed src="http://www.youtube.com/v/b0yDSgmC6_w" type="application/x-shockwave-flash" width="425" height="350"></embed>
 [[media:Doin_the_Shake.avi|Right-click here and select "Save Link As" to download the video (.avi)]]
 |}

@@ Line 206: / Line 206: @@
 ! 6
 |align="center"|Quantitative Results (plots, calculations). How do these relate back to the engineering specifications? How do they verify the quality of the design?
-| align="center"|Equations could not be found to calculate the exact stress experienced by the diaphragm, but the use of s=F/A, where s is stress, F is the force, and A is the area of the diaphragm, predicts the stress to be on the order of 102 Pa.  Experimental data from Mars and Fatemi’s paper, Multiaxial Stress Effects on Fatigue Behavior of Filled Natural Rubber, indicates a 50 million cycle lifetime at a stress of 7.5*105 Pa.  Given that the stress in the diaphragm is three orders of magnitude smaller it is reasonable to say that failure due to fatigue will not happen.  The rubber will decay through simple aging far before sufficient cycles would be reached for fatigue failure.
+| align="center"|Equations could not be found to calculate the exact stress experienced by the diaphragm, but the use of s=F/A, where s is stress, F is the force, and A is the area of the diaphragm, predicts the stress to be on the order of 102 Pa.  Experimental data from Mars and Fatemi’s paper, Multiaxial Stress Effects on Fatigue Behavior of Filled Natural Rubber, indicates a 50 million cycle lifetime at a stress of 7.5*105 Pa.  Given that the stress in the diaphragm is three orders of magnitude smaller it is reasonable to say that failure due to fatigue will not happen.  (See figure 5 for a the Force vs. Time plot for one of the springs). The rubber will decay through simple aging far before sufficient cycles would be reached for fatigue failure.
 |-
 ! 7
@@ Line 214: / Line 214: @@
 |}
 {| align="center"
-|+[[Image:aftershock.png|right|thumb|300px|Figure 5: Front, Right, Isometric Views for the Shake Table Assembly]]
+|+[[Image:ForceVTime.JPG|right|thumb|300px|Figure 5: Force vs. Time Plot]]
 |}
 {| align="center"

@@ Line 160: / Line 160: @@
 ! 5
 |align="center"|Boundary Conditions and Loading
-| align="center"|The motion of the mirror is caused by a weight rotating at a variable speed at the base of the shake table assembly.  The motion produced as a reaction to this inertial loading is constrained by the diaphragm assembly.  The diaphragm is also responsible for connecting the shake table assembly to the frame of the light.The displacement observations showed that the aftershock mirror exhibited a maximum angular displacement of 20 degrees.  This displacement was subsequently used as a model criterion when the shake table and assembly and diaphragm were modeled in ADAMS. (See Figure 3 for a plot of the Angular Displacement vs. Time).
+| align="center"|The motion of the mirror is caused by a weight rotating at a variable speed at the base of the shake table assembly.  The motion produced as a reaction to this inertial loading is constrained by the diaphragm assembly.  The diaphragm is also responsible for connecting the shake table assembly to the frame of the light.
 |-
 ! 6
 |align="center"|Quantitative Results (plots, calculations). How do these relate back to the engineering specifications? How do they verify the quality of the design?
-| align="center"|
+| align="center"|The displacement observations showed that the aftershock mirror exhibited a maximum angular displacement of 20 degrees.  This displacement was subsequently used as a model criterion when the shake table and assembly and diaphragm were modeled in ADAMS. (See Figure 3 for a plot of the Angular Displacement vs. Time).
 |-
 ! 7

@@ Line 13: / Line 13: @@
 The Aftershock uses an internal microphone in order to capture low frequency sounds.  Using a circuit board it transfers and amplifies the signal to an electric motor at the opposite end of the light.  The motor is rigidly attached via a bracket assembly (see figure 2) to a mirror, and contains a weight on its axle to provide uneven interial loading to the assembly. The shake table assembly is then bound in a neoprene diaphragm that allows relatively limited motion of the shake table.
-[[Image:Bracket_Assembly.png|right|thumb|300px|Figure 2: Bracket Assembly]]'''
+{| align="center"
+|+[[Image:Bracket_Assembly.png|right|thumb|300px|Figure 2: Bracket Assembly]]'''
 ==Parts==

@@ Line 13: / Line 13: @@
 The Aftershock uses an internal microphone in order to capture low frequency sounds.  Using a circuit board it transfers and amplifies the signal to an electric motor at the opposite end of the light.  The motor is rigidly attached via a bracket assembly (see figure 2) to a mirror, and contains a weight on its axle to provide uneven interial loading to the assembly. The shake table assembly is then bound in a neoprene diaphragm that allows relatively limited motion of the shake table.
-{| align="center"
+[[Image:Bracket_Assembly.png|right|thumb|300px|Figure 2: Bracket Assembly]]'''
-|+[[Image:Bracket_Assembly.png|right|thumb|300px|Figure 2: Bracket Assembly]]'''
-|}
 ==Parts==

@@ Line 137: / Line 137: @@
-The table belows explains the caclation of the force on the gears:
+The table belows describes the maximum angular deflection of the mirror:
 {| border="1" align="center"
-|+ '''Table 2.2: Force on gears'''
+|+ '''Table 2.2: Maximum Angular Deflection of Mirror'''
 ! width="50"| !! width="200"| !! width="400"|
 |-
@@ Line 169: / Line 169: @@
 ! 7
 |align="center"|What changes could be made to improve the quality of this design with respect to this engineering specification? What trade-offs would this introduce?
-| align="center"|
+| align="center"|An actuator system could be used to control the mirror geometry instead of the weight and diaphragm system.  American DJ has produced several lights using this technology, including the Confusion sound sensitive light system.  This system is much more prone to damage in harsh environments but can produce far superior lighting patterns, both in terms of lighting area and pattern complexity.
 |-
 |}

@@ Line 174: / Line 174: @@
 {|
-[[Image:Mirror_Angular_Deflection.JPG|right|thumb|300px|Figure 3: Angular Deflection of the Mirror]]
+|align="left"|[[Image:Mirror_Angular_Deflection.JPG|right|thumb|300px|Figure 3: Angular Deflection of the Mirror]]
-[[Image:Diaphragm_Pro_E.png|right|thumb|300px|Figure 3: Pro/E Model of the Diaphragm]]
+|align="right"|[[Image:Diaphragm_Pro_E.png|right|thumb|300px|Figure 4: Pro/E Model of the Diaphragm]]
 |}