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When I bought my Panasonic PT-L200U in June it came bundled with a 67x38" 16:9 Da-Lite Model B matte white pull down screen. I have the screen ceiling mounted in front of my RPTV. I have used mattes on my 4:3 RPTV for years to mask for 16:9 and 2.35:1 aspect ratios. I tried to figure out a good solution for masking the pull down screen. I used some black velvet but could not come up with a good way to attach the bottom mask to the screen, as the fabric when clipped to the sides does not lay flat against the screen and causes the screen material to bow out. As a temporary solution I started using the screen only partially rolled down for 2.35:1 films, so that only the top needed to be masked. Draping the black velvet over the top of the screen case and clipping it on the sides worked OK but still caused minor distortions in the screen. Then I had a brainstorm -- instead of masking the 16:9 screen for a "small" 2.35:1 image, why not build a larger DIY 2.35:1 aspect ratio screen, so that is what I did. The whole point of framing films at the wider aspect ratio is to make more of a visual impact -- to get the most out of the format a 2.35:1 film should be much wider than a 16:9 film. Keeping them the same width but making the 16:9 film taller defeats the purpose of the "scope" format. I have the 2.35:1 screen mounted about 1.5 feet farther from the PJ and about 6 inches lower so that I can use the PJs optical zoom to fill either screen as needed. Now I can watch 16:9 films and HDTV on the 67-inch-wide screen and 2.35:1 films on the 94-inch-wide screen.
 

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Discussion Starter · #5 ·
Unfortunately, adding a second screen isn't an option in my house BMAG. Besides, I'm already working with 4:3 screen so adding a 2.35:1 screen wouldn't help with 1.85:1 material. :(


Anyone else have any suggestions?
 

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Experimenting with fabric attached above&below pic with velcro tabs.

So far,so good.

Price=rock bottom

speed=very good.
 

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Quote:
Originally posted by REW
Experimenting with fabric attached above&below pic with velcro tabs.

So far,so good.

Price=rock bottom

speed=very good.
How do you get the fabric to stay flush against the screen material. You obviously can't put velcro in the middle of the screen, so how can the fabric stay flat against the screen? That is why I gave up on the idea of using "mattes" on my 16:9 pull-down screen.
 

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I diy a roll-up masking of simply a piece of black cloth across the top of the screen.


It's powered by a 24v gear-motor of size of an AA battery. It turns a rod of 1" in diameter. The whole assembly was secured onto the bottom of the screen case; just change the 2 screws at bottom ends of my Steward to a longer ones; in my case.


All parts cost
 

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Frank,


Your masking sounds good. Where did you find the gear-motor and what is the material of the rod (wood, metal, etc)?


To post a picture/file: hit the post reply button at the bottom of the last reply; then go to the bottom of the reply screen and hit the button for attach file; then attach your pic file from your PC.
 

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MIKeTC,


It's a aluminium tube. You need an end cap to bring the tube and the shaft of the motor together. I order several from a mechanic. $30 for ten.


He makes it out of a aluminium rod. Piece of cake for him.


The motor is from flea market.


Frank

 

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Frank,


This is what I've been looking for. Thanks for the photos but I have a couple questions:


1. I'm sorry, but I'm little confuse with your end cap photo (plug.jpg). Are you using this end cap in a different application (pulling out a ceiling mask) than just moving the masking up or down? If it is, do you have a photo of an endcap that is being used in the masking up/down assembly?


2. What is the RPM of your motor? How fast is your motor going when lower/pulling up your masking? How does it reverse?


3. What do you think of the 40RPM 115VAC gear motor from the site you gave me (Cat# ACM-108)? Does this do reverse?


4. How do you couple the other side of the tube? End cap w/ Ball bearing or other method? Photo please, if you have it.


5. How do you finish the bottom of your masking while keeping it straight and weighted down?


5. Are you really in Hong Kong?
 

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TPL,

Nice effort,thought provoking.Cheap.The Sultan of Cheap.The Marquis of Scrounge(Tm).


Manual method,use rod of wood or metal with fabric attached and position it with velcro.Could work with constant height,variable width screens as well.
 

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MIKeTC,


1, I ordered 10 caps and use them in both situation; at ends and winch. The screw on the cap serve 2 purposes; it goes right down to the center to lock the motor shaft and also grasp the tube also. You could make it from wooden rod if you can¡¦t find mechanics around. A screwdriver, cordless drill and a handsaw are the tools needed for the entire job.


2, Around 30 RPM.. It travels at 10 ft per minute and it¡¦s perfect. It would be difficult to control if it travels too fast. It is a DC motor. You just reverse the wires to change directions. I use a RF control ( @US$5 ,and works with 12v dc as the motor¡Kpefect!!!) on it, but an ordinary 2 ways switch will do.


3, I¡¦m not familiar with AC but my friend told me it will reverse by wiring differently on the capacitor. However, it's safer and easier to work on low voltage DC for novice.


4, I put a bearing at the other end as I came across a suitable one at @ $1. You could use end cap here also. Just put grease on it for lubrication.


5, You can fold the bottom of the cloth either by sewing or adhesive tape to a sleeve. Insert anything straight with weight. I put screw rod in it.


6, I live in HKG but I bought all the gears of my HT from US; BG1209, Faroudja¡K.to horns. One sent me his Faroudja 400 before taking any money from me. You have great guys here. Just ask if you want me to help.


This is my first attempt so it is far from perfect though it works. It is longer than it needs and looks ugly.


I recommend to use a bigger tube ; 1.5 ¡§ in diameter . It bends easily at the middle if it is not strong enough. Use a metal strip as the weight is better; 0.75¡¨ tall X 0.125¡¨ thick aluminium strip.


Regards


Frank
 
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