Axiom Home Page Forums General Discussion The Water Cooler Looking for black cord

I am working on my projection screen masking system (to cover up the top and bottom "gray" bars on the screen).

Anyway, I found a really simple system that uses 2 pulleys (one on the left, and one on the right) that allows for the top and bottom "masks" to move together, so if I lower the top mask, it pulls on the cord, over the pulley, and pulls up the bottom mask as well.

Anyway, I picked up the smallest pulleys I could find, but they still aren't really small. Now I need some cord, rope, string, whatever, in black to connect everything up. I am having a hard time finding anything. I would think that it would need to be 3mm - 5mm in width, and I need about 20 feet of it to make sure that I have enough.

I've seen various types of materials used, but does anyone know what would be strong yet fall within the 3mm-5mm width, and of course be black, and fairly cheap? I know it is a crazy request, but Dr. Google is helping me find stuff, but I am not sure what materials would work best.

You could try black parachute cord for about $4 for 50 feet.

http://www.vtarmynavy.com/parachute_cord.htm

Not sure if the diameter would work.

Nick you may want to try using braided fishing line, something like PowerPro ... it is extremely thin, flexible, comes in various colors and is readily available at just about any store that sells fishing supplies.
PowerPro

If you go to a marine supply store, you should find all kinds of choices.

Of course, I just realized you are in Iowa and there are probably not many Marine Supply stores around in a landlocked state. Online maybe?

I'm sure you will find something but if not, just let me know what you want and how long and I can pick it up for you and ship it to you. My buddy runs a marine shop so pricing should be decent.

The parachute cord is pretty good, but it will run me about $15 for something that might not work due to its size and the web site claims that it may be "flat" which might "jam" in the pulley.

The braided fishing linemay work, but I am concerned that the color would come off as noted in the "cons" section of the bottom of the page. It would run about $15-$20 once factoring in shipping.

These do give me a few other ideas to look in to. Murph, I'll let you know if I need something. Do you have any links to the type of stuff you are talking about?

Nick,

Find some white cotton rope in the exact size you need.

Then dye it black with RIT dye...

Just my .02...

WhatFurrer

I was thinking of some 3 strand Marlow line or some 3 strand polyester rope. It often comes as small as 4mm. Any 3 strand line actually. You could even just go get some at a hardware store. Although, I might avoid nylon unless you like splinters. Color might be the only issue at a hardware store.

I say three strand because then you can do a 3 strand eye splice so you don't have a big knot running through the pulleys all the time.

I had a second thought about the marine supply stores though. They tend to sell in bulk by the reel so it would be costly and you would end up with 300' plus. Maybe you could go into the screen retractor business???

I'll fire my buddy off an email to see if he has 20' scraps of 4 to 6 mm black line laying around, just in case.

Slightly off-topic here, but do you mean you found a plan online for building a screen masking system?

Nick

If there is a web site associated with the pulley system you found could you post the link. I don’t have a projector yet but a DIY masking system is one less reason not get one.


@ Amie

Screen masks are usually black material that covers the top, bottom and or sides of your HT screen so that only the reflective area that is exactly the same size as the picture you are projecting is uncovered. Without the mask the unused part of the screen will likely show up as gray bars above, below or to the sides of the picture rather than a nice sharp black boarder as I the pictures in the link below.

http://www.projectorcentral.com/235_home_theater.htm

Sort of. It took a lot of searching, and it could be tweaked to be better, but for a start, it is pretty simple...

Now for my "master" MSPaint skills...
Basically, the screen is gray, the "masks" are black (I made them a little larger for the diagram to differentiate them more, the pulleys are blue at the top, and the "string" or cord is also blue.

The top and bottom should be fairly evenly weighed out. When the top moved down, it makes the bottom move up and vice versa.

Ok that is so simple I feel stupid.

If the masks are cloth is there something like a wooden/metal dowel at the top and bottom of each mask to hold them straight or do they just ride against the screen to keep them flat, or are the masks solid?

I’m guessing you could also make a similar rig for the sides for 1.33:1 material. I watch lots of Anime most of which is 1.33:1.

Nick I've used the camo PowerPro for years and have never seen or heard of the color coming off, in fishing applications that stuff will cut your fingers though.

Also...

I use the 130# 'DACRON TROLLING LINE' (second product down) for our down riggers, it does come in black and I've never seen nor heard of the color rubbing off either. This is strong stuff, earlier in the year we were trolling for grouper on a shallow reef with the down riggers and I was running one of the weights a little low and caught the reef, rather than breaking the Dacron it twisted the down rigger and tore the built-in rod holder out of the boat. I believe it would be perfect for your application.

Dacron Trolling Line

I'm guessing you're not going to use that stuff again for fishing. I think I'd rather lose the fish than the rod and rod holder...

Ken luckily I didn't lose anything, the gimble mounted down rigger was pointed at a 90* angle from the back/front of the boat, whenever the ball caught the reef it twisted and broke the gimble bar inside the flush mounted rod holder on the boat and spun the rod holder on the boat.

I've learned my lesson regarding the loss of rods on the boat, whenever we are running or trolling I fasten the rod and reels along with the down riggers via cable and quick connects to the boat ... from experience, of course.

I was originally going to try something more "solid" at first before I found the pulley idea. But then, with the way my VP150 is right under the screen, and a lack of height above the screen due to it being under duct work, something more "pliable" was needed.

I have two 10' tubes of 1/2" conduit. The stuff stays rigid enough for this application. I will cut them down to the correct sizes as well. Then I have a piece of black velvet cut to make the two "masks". One end was folded over and sewn to make a place for the metal conduit to go in to. The fabric will be adhered to the conduit to make it a nice secure, and ultra smooth fit. The bottom will have the fabric "hanging" from the conduit, and the top will have a wider strip of fabric with the top secured to the ceiling (to hide the pulleys and for the next reason) with the conduit end hanging down. This again will provide the straightest and smoothest edge where it matters most, along the screen image. I didn't quite depict that difference in the top with my diagram, but basically, the diagram would only need the cord, line, rope, whatever for the top mask to be drawn to the bottom of that mask where the conduit is.

My biggest thing to experiment with is how much "slack" will be in the top mask. I don't want it to start looping down too much.
I may just add something a little more rigid behind the top mask to hold it flat a little, but not all of the way up so that I won't be running into the ceiling with the rigid part. Another option would be to put metal conduit at both the tops and bottoms of both masks, and then just attach to the tops like I DO have in the diagram. Then it is still a flexible mask, but I can pull the top mask from its top, and still have a smooth surface on the bottom. Then I would just add some sort of small hanging "curtain" above the masks and screen to hide the pulley system. Heck, I could even probably just attach the line (rope, string, etc) directly to the top of the top mask without any additional horizontal support. As long as the pulleys were "pulling" it outward, it should stay pretty flat. I would have my daughter (who knows how to sew) put in some "button holes" so that the fabric doesn't tear.

Lots to work out, but it is very doable and should be great when it is done.... Even if it is a "poor man's" solution and not as sophisticated as the powered professional units ($2500 to get one from Carada to match my screen). Then again, my cost for this is currently less than $20 with the fabric, conduit, and pulleys. Now for the line....

Glad to hear it, Rick. I live in terror that I'm going to lose one of my father in law's rods/reels whenever I go fishing with him. He likes mentioning how expensive they are...

Ken it sounds as though you like offshore fishing as much as I do ... if you ever find yourself in Florida give me a shout, we'll get out and do a little fishing, I promise you'll never hear about how much all that stuff cost.

Now to get back on topic.

Nick, you really need to get some fishing line to hang your screen, anything less just wouldn't be right.

Heh... I appreciate the offer Rick. I actually stink at fishing, but it's the name of the game on my wife's family's Baja vacation. They go for the dorado, but the times I've been, we've mostly ended up with rock fish. Can't imagine what fighting a grouper is like!

I've actually earned a reputation in the family for catching weird things. The first time I went, all I caught was a scorpion fish, an eel, something red with big glassy eyes (tasted terrible), one trigger, and the bottom. A whole lot.

Last time I caught a scorpion fish, a needlefish...

Sorry, no luck. Several choices to choose from in black 4, or 6 mm, various braid options too but he only sells by the reel.

I did a quick google for "Black rope" and "Black Shock cord" and found a ton of inexpensive options. Even ebay. Most is a tight braid but there are lots of ways to splice without a knot, depending on the material you go with.

Really? Whodathunkit?