Complete
the Basic Front
Disassembly Procedure in preparation for beginning this
procedure.
(NOTE: You may click on any image
to pop up a larger version of the image with arrows indicating
action points.) |
Step 1 |
Step 2 |
Step 3 |
| Always
wear clean and dry latex gloves when handling the screen stack
elements. |
This
is a close-up of the top of the frame at the center. In this image
I am lifting at the center of the frame with about 5 lbs. of
force. Notice the extreme amount of frame flex present. There is
actually a gap between the frame and the screen stack! That gets
fixed in this procedure. This deficiency is what makes it
necessary to handle the screen exclusively by the corners. |
With
the Screen Assembly resting vertically, top rail on the floor,
remove ONLY the clamping strips. Top and bottom clamps have 5
screws each. Side clamps have 3 screws each. Note how I am
arraying the clamps/hardware. This insures that the clamps and
each piece of hardware goes back exactly from whence it came. Not
a critical point here, but a good habit to develop. |
Step 4 |
Step 5 |
Step 6 |
| Handling
screen elements by the outer 0.5" of the edges, remove entire
screen stack from the frame and lay it down flat on a 100% cotton
sheet (not brand new; washed several times at least) with the
Front Panel on top.
The screen elements have the
following thicknesses:
Front Panel = 0.079"
Lenticular = 0.039"
Fresnel = 0.078"
In addition, there is an
approximate 0.031" free gap between the stack and the frame
with the clamps fully seated.... NOT good.
|
Separate
the Front Panel element from the screen stack, making sure not to
slide the faces across one another. Set the Front Panel element
aside, or PREFERABLY, package and store it properly NOW.
I have mine stored inside two
large garbage bags, sandwiched between two heavy-weight pieces of
cardboard, and clamped between the wall and my DVD shelves. Just
make sure it stays flat and safe from impact/scratches.
|
Here
is the empty Front Mask frame resting upside down against the
wall. |
Step 7 |
Step 8 |
Step 9 |
| Corner
of the frame showing the joint between the corner fittings and the
sides. Note that there is only ONE screw on each leg of the
fitting.... I'm pretty sure the engineer knew what he was
doing when he put THREE holes in the fitting's design. I will
likely install the remaining 16 screws if I can find an exact
match to the stock hardware.
The other point I want you to
see is the screen element bearing surfaces. The front surface is
right at 9/16" wide. Thus, I chose 1/2" as the width of
the gaskets to maximize bearing surface, while insuring that the
gaskets will not protrude beyond the edge of the frame.
|
Knowing
the element thicknesses and the gap width, it was possible to
calculate the approximate total gasket thickness needed to insure
a static frame to screen stack installation with the clamps
installed. I know many folks have used basic weather stripping as
gasket/spacers, but I chose not to. Weather stripping is
intentionally compressible, and is very unstable in the shear
direction when compressed. This doesn't make for a very good
clamping gasket.
I chose to use a cloth
impregnated, hard rubber sheet in 1/16" and 1/8"
thicknesses. This sheet material is similar to pump diaphragm
material, is almost incompressible, and has very good shear
adhesion properties.
Source for mine was
Orchard Supply Hardware (OSH): 1/16" sheet (a12065639 @
1.96/sq. ft.) and 1/8" sheet (a12065647 @ 3.96/sq. ft.)
Using the square and numerous
single edged razor blades, I cut the sheet into 1/2" strips.
|
Before
installing the gaskets, make sure to clean and dry the mating
surfaces with something like alcohol prep pads (EXCEPT the screen
elements). The frame had a lot of chalk-like substance on it, and
the gasket material was dusty. Clean surfaces will
"stick" better. Make sure you dry all of the alcohol
residue away thoroughly. |
Step 10 |
Step 11 |
Step 12 |
| Tough
to see, but here you can see a section of the outer gasket in
place against the frame's screen element bearing surface. On the
outer gasket, I chose to completely line the entire perimeter with
the 1/16" gasket material. |
Here
you can see the end of the top bracket installed with the
1/8" inner gasket material in place. This combination gave me
just enough compression when the clamps were installed to secure
the screen stack, but still afforded the option to add another
1/16" in the back at a later time if necessary to compensate
for frame flexing over time.
Difficult to see here, but there
is a pronounced gap in both corners of the top rail. As the screen
elements have a very true edge, it is obvious that the frame is
"warped". It is critical that the screen stack be
mounted squarely against the top rail and that it be centered from
side to side. Not hard to fix, but necessary....
|
Center
the stack side-to-side in relation to the top rail by insuring
that there is equal space between the edges of the stack and the
top corners. Tighten the center screw ONLY insuring that the
screen stack is fully seated against the center of the top rail.
Then tighten the left-center, and right-center screws in order.
Gently lift the appropriate corner a bit if necessary to seat the
stack at the screw location. Finally, tighten the left and right
most screws. If there is a gap, you will have to lift the corners
sufficiently to close the gap while you tighten the screws. With
the top clamp completely installed, you should be able to turn the
screen assembly right side up and the screen stack will be
retained (hanging) by the top clamp. |
Step 13 |
Step 14 |
Step 15 |
| The
side and bottom brackets need not be completely lined with the
inner gasket. Long strips at each screw location is sufficient.
I
ran out of time in this session, and wasn't able to properly
set/tune the screen. I simply tightened the clamps from top to
bottom and center to corners to get everything back together.
|
OK,
don't freak out. I can see the "sag" too. Actually, it
only amounts to about a 1/16" separation between the elements
in the stack 2/3 down from the top.
I purposely used a very high
flash level on the camera to accentuate it. It's very hard to see
without a super bright light or looking at less than 5 degrees
from the parallel.
I needed this pic to analyze
what MY particular frame does to the stack when installed on the
chassis. The frame/stack tends to behave differently when
installed vs. free-standing or suspended in free-air.
|
Even
with the 1/16" separation, Matrix still looked
awesome... We are talking MAJOR improvement. I watched it in
daytime and in low-light. Both conditions showed marked
improvement in light level, elimination of front-lighting glare,
improved color saturation, and most importantly.... well, it's
hard to describe...
I've seen this movie many, many
times, but it was like I was seeing it again for the first time.
Every few seconds I picked up on a new image detail I had NEVER
SEEN BEFORE!
Hang with me... In Part II of
this procedure, I will work on eliminating
virtually all of the screen element separation and consequently
the visible lenticular distortion. 
|
)
)
)
)
)
)
)
)
)
)
)
)
)
)
)