[tiddler]

Introduction

I have noticed that there are many people, myself included, who try to improvise an interim screen when they first get a projector. In particular people who's situation requires a retractable screen. This is typically due to the desire to have a screen that will be in front of the existing TV and entertainment equipment or a fireplace etc. The common solution is a bed sheet such as . . .



I even entertained the idea of a slanted screen to accommodate the projector offset without using keystone correction . . .




I also tried some material from a local fabric store.

Sportlight Material & Bungy Cords:



In this photo there is a sample of Da-Lite High Power (left square) and High Contrast Matte White (right square) in front of the gray sport light screen.


Here we have a couple of screen shots on the gray Sportlight material. It was a bit too dark but not a bad material. It also comes in a white similar to BOC.

So you can see that I went through all the typical trials of very simple cheap DIY screen solutions.


Exploring Some Ideas:

Over the past couple of years or so that I have been tinkering with screen paints, I have often mused about how I might make an interim screen if I were to attack the problem now. Of course I have learned that the best screen material that is readily available to just about everyone everywhere is Blakout Cloth (BOC). The problem with BOC is it typically comes in a 54" width. If you build a frame and wrap it around the frame and staple it, you lose about 4" or more. I had often ponder a method to reduce that to an inch per side. Bringing these thoughts to this rollable interim screen question I came up with this design idea.



When I looked at the 1x2s I decided they were not stiff enough so I opted for the 1x3s. They come in 8' and 12' lengths. I also decided to go with the construction lumber because it is cheap and the edges are already round with about a 1/8" radius.

I bought 4 of the straightest 8' 1x3z I could find and 3 yards of BOC.

I marked a line on the 1x3 to align the BOC.



I had that wooden thing kicking around so I used it to align the ruler with the side of the 1x3. You could use anything square like a piece of 2x4. This was necessary due to the rounded edges.

I then used the fact that the BOC has parallel edges to mark the location to cut the cloth to size with a square edge.

This post has been edited by tiddler: 21 January 2009 - 03:03 PM

[tiddler]

I was trying to keep the tools required to a minimum, so I used a paper stapler to tack the BOC along the line drawn on the back of the 1x3.



Once the BOC was tacked in place I attached the second 8' 1x3 to the first with 1 1/4" drywall screws. I used these because they are cheap and small gauge #6 screws. I had hoped the smaller gauge would reduce the likelihood of splitting. For the most part the drywall screws worked well except near the ends. To repair and prevent the splitting I wrapped some hockey tape around the ends of the boards.

Once I had the top and bottom sandwich bars attached I rolled upt the screen with the bottom bar. I added a hook & eye to the end of each top bar and bottom bar. I looked for the hooks that have a spring loaded locking mechanism to ensure the hooks could not slip out of the eyes, allowing the screen to fall. I took the screen upstairs to hang under my own screen valance.



Mechanically I was quite pleased with this rough prototype. The materials had been very easily found and quite inexpensive. The tool requirements were also minimal. All the attributes you would want in an interim screen solution. But . . .



As bad as it looked I know this is a matte finish material so I decided to throw some images on it and see just how bad it looked in use.

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As a very short term solution this would be just OK. Certainly better than a bed sheet but the larger waves were quite noticeable and distracting. The smaller ripples were not noticeable in the image due to the wide light dispersion of a matte material.

I felt that there might be something that could be done to fix this without making things too complicated or expensive so I went back to the drawing board . . .

[tiddler]

Tab-Tensioning

I rebuilt the screen with longer top and bottom bars. I played around with the typical tab-tensioning with side cords and tabs. It is a delicate balancing act between tension and bottom bar weight. I could not get it to work using BOC.

I kept thinking it would be nice if there were side bars. They would have to be removable to allow the screen to roll up. At first I thought about side bars that would swing down and lock in place once the screen was lowered.



This idea has merit but not easily implemented just to try out the concept so I came up with this . . .



The side bars would be removable and simply sit between the top and bottom bars. There would need to be some sort of stop to hold the side bars in place. I had some waist band elastic kicking around so I stapled some looped to the side of the screen material and slipped the boards through the loops. Some screws were used to hold the bars in place and . . .



I sprayed the material with warm water to see if the wrinkles would come out. That is why the material looks a bit blotchy. The material was perfectly flat so it was back upstairs to see how it looked . . .

This post has been edited by tiddler: 21 January 2009 - 03:17 PM

[tiddler]

Image Quality

In the end isn't that what really matters. This screen is very smooth and flat. The screen is absolutely invisible in the image. Even with some low ambient light, white walls, and white ceiling, the screen performed very well. Way beyond my expectations for a white screen.







Click here to see all the screen shots.

This post has been edited by tiddler: 19 January 2009 - 06:06 PM

[tiddler]

Where It Stands Now

This is a darn good way to make a "Slapco DIY Tab-Tensioned Rollable Screen". It only required the very basic tools shown in this photo:



I would suggest using a staple gun instead of the paper stapler. The paper staples worked ok if the wood was soft.

I posted the following question in another DIY screen forum with no response. Then it occurred to me the true die hard DIYers are probably here at Lumen Lab. While I think a DIY solution should be practical in terms of materials, fabrication, and cost, those are not always limiting factors to a die hard DIYer.


The BIG Question

Just out of curiosity, does anyone believe this basic design of a DIY Roll-able Tab-Tensioned BOC Screen could be made attractive enough to hang in the living room?



Of course there would be a little more cost for better quality lumber & fittings, a few more tools required, and naturally a bit more effort, but do you think it could be done in such a way that you would not mind it hanging in your living room when not in use?

[tiddler]

I should mention, that for some reason, I am eager to try to make a version of this that is attractive enough to hang in a recreation room, if not a living room, but I really have no need for it. I suspect there is a challenge in it for me, but I really can't justify the effort and cost if it will not get used. The concept has been proven to be practical, so now it is just a case of proving that it could be done with some elegance. Not only elegance but I have ideas of how to integrate 2.39:1 masking into the design.

If there is anyone in the Ottawa Canada area, that would be interested in taking this off my hands, if I do make it, please let me know. Of course this would all be dependent on the thing looking and working to your satisfaction. If you felt inclined to cover some of the cost of materials, that would be appreciated but not expected.

This post has been edited by tiddler: 21 January 2009 - 03:29 PM

[rengate]

I really like your idea I have been pondering the same. Why not use 2 pcs. of half round on the bottom, instead of the square corners it would be smooth.

[tiddler]

rengate, on Jan 21 2009, 01:03 PM, said:

I really like your idea I have been pondering the same. Why not use 2 pcs. of half round on the bottom, instead of the square corners it would be smooth.

If you can find a 2" dowel to split or 2" half round that would be ideal.

In a more finished version of the two 1x2s I would use a router with a 3/4" round over bit.



With the two boards screwed together you can use a full 3/4" bit because the bearing will be able to ride the edge of the other board. Or if you have a router table you can stand the boards on their edge and let the bearing ride the face of the board.

This post has been edited by tiddler: 21 January 2009 - 05:14 PM

[tiddler]

Update

The research & development side of my brain has overwhelmed the practical financial side and I have started work on a more elegant version of this roll-able BOC screen design.

So far I have acquired some select pine boards. I was happy to find you can get 1x3 select pine in 10 foot lengths. After picking through the entire stock at my local Home Depot I found 5 suitably straight boards. 4 of them for the top and bottom sandwich bars and one to cut in half to make the side bars from.

I discovered that the largest radius rounding bit I have is 1/2". I also discovered that to get a larger radius bit I would have to get a router that has a 1/2" collet. So I settled for the 1/2" radius for now.

So far I have cut the top and bottom bars down to 9' and put a 1/2" radius on the outside corners of the bottom bar. I also put the 1/2 radius on the bottom corners of the top bar even though they are not needed. I did not extend the 1/2 radius all the way to the ends of the bars. I wanted to leave an area at the ends with flat surfaces to accommodate the side bars.

I also routered a small detail on all the other corners. It is my intention to paint the bars matte black and then paint the corner detail metallic gold. I will try to use all brass hardware and I am hoping the gold will go with the brass to give a more elegant look to the whole thing.

I had some vinyl material hanging from the strapping version of the top bar so I attached the rounded bottom bar. The vinyl was worse than the BOC at retaining lines from being rolled up, so I figured this would be a good test. The rounded corners definitely makes a big difference. There are no apparent lines in the material when rolled down.

So now I have to find an attractive way to seat the side bars, and hold the screen in the rolled up position. I am also looking for suitable material to use for the 2.39:1 masking, and figure out a way to hold it in position with a nice straight edge.


Before I Forget . . .

I have not abandoned the traditional idea of a roller to retract the screen. The idea of using a PVC plumbing pipe was suggested to me by Bud16425 (AVS member). I have looked at them and for some reason the white drainage pipes seem stiffer than the black plumbing pipe. You can get nice end caps for the pipe. I found the 4" pipe seems to be very stiff and that is what I would try using. You could drill a hole in the center of the caps and install a bold as the axle pins.

I say I have not abandoned this idea but I should point out that I have not found a readily available material that would be suitable for simple retractable screen design. I think this top roller design could be combined with the tab-tension side bar idea but I'm not sure what will be gained by using the top roller. In fact the whole thing would be bigger and probably less attractive. If you were going to hide it all in the ceiling there is some advantage to it though.

Better Tab Development

I stopped into a fabric store on the way home from work and found some interesting things to play with. First thing I noticed were those iron on patches. There were the usual blue jean type and some very thin nylon ones. They had some 2x3" packs of 10 in the blue jean type that I grabbed. I also found some nice black elastic that looked about the right width for stapling.



First I tried simply folding the elastic over the edge of the BOC and stapling it in place (right tab). Then I cut a slit in the center of one of the iron on patches and folded it over the edge with the elastic coming through the slit. This resulted in a very finished looking tab but proved to be very stiff. I think it would be problematic when the screen was rolled up.

I went back to the V shaped tab to spread the thickness of the elastic out, (left tab). I then covered the elastic only on one side with an iron on patch. This was strong and much more flexible but I did not like the exposed staples on the back (shown bellow).



I tried to staple from the other side so the folded staple ends would be covered by the patch. The problem is you can't see where the elastic is and I kept missing and making a mess.

Finally I tried the V tab with a patch on both sides (Lighter blue bellow). It looks much better but is starting to get pretty stiff again. I think I may get some of the thinner nylon type patches and try them.



I am trying to develop fabrication methods that do not require a sewing machine and the skill to use it. If you have one and know how to use it then attaching the tabs should be quite easy for you. I would cut out round patches of the BOC and use the center slit idea to wrap them around the edge. Then sew them in place. This will hide the ends of the elastic and help to spread the tension out.


Masking Material

There was very nice clerk that showed me a lot of different materials that might be suitable for masking. I was looking for something inexpensive, not stretchy, and not shinny. I settled on a cotton material ( I will have to get the exact name). It is quite flat as you can see in the photo bellow. Much better at absorbing light than the matte black border on my screen.



I also found a way to use double sided carpet tape to make a very smooth straight fold-over edged. I will try making up a full width mask and attach it to the prototype setup I am playing with in the basement. I am optimistic that this approach to masking just might work. Since the masking is done with flaps that are part of the screen they roll up with it. Much easier to handle then long masking panels. The difficulty I see now is in how to place the edge properly when assembling the screen.

This post has been edited by tiddler: 24 January 2009 - 07:40 AM

[tiddler]

Masking Flap Trials

I managed to use double sided carpet tape to fold over one of the masking flaps. Then I ran out of carpet tape. I attached the elastic tabs for holding the edge in place and then I rigged up some side bars to give it a try.

Of course the bottom flap is the one that will be the most difficult. The hard part will be getting enough tension on the upper edge for it to stay in place and straight. I was too lazy to attach the flap properly so I just clamped it to the bottom bar to try it out.



When the masking is not required it will be released and either hang down covering the bottom bar or it could be pulled back up behind the bottom bar. The top flap will be simply draped back over the top bar to get it out of the way.



As you can see the edge is fairly straight. I will have to use much stronger elastic for the bottom masking flap. The upper one should be easier because gravity will be pulling in the right direction.

I still need to devise a method of mounting the flaps. They need to be in front of the screen material and therefore must be stapled to the back of the front half of the bars before the screen material. That will obscure the line that I use to align the edge of the BOC when stapling it to the bars. I was thinking I could use a string as a guide line or even a chalk line.

The other problem is how to attach the flaps with the correct amount of material sticking out. I think I will try to leave a little ectra material. I would rather have a little wave in the masking material then not have enough to reach the proper location on the screen.

I am still optimistic that this will work. I need to get some stronger elastic and try attaching the flap properly to the bottom bar. If the bottom flap works the top one should be no problem.

One side benefit to these flaps is that the top and bottom bar don't actually act as screen borders. That means they could be painted any color that suits the decor of the room. In most cases white will help to make the rolled screen less obtrusive against the typical white ceiling. If the back of the screen is the same color as the bars then the whole think might not look too bad when rolled up.

[rengate]

So what kind of material is that black stuff? Is it felt?

[tiddler]

rengate, on Jan 25 2009, 03:41 AM, said:

So what kind of material is that black stuff? Is it felt?

It is a heavy cotton material that is not stretchy. I looked at the felt but it would pull apart under the tension I would be applying to it. The next time I am in the fabric store I will get the exact name of the fabric.

[rengate]

Great thanks

[tiddler]

Not All BOC Is Created Equal!

I have been to a couple of fabric stores lately and looked at BOC at each. Most stores have more than one type of BOC. The type that I used on the Slapco Rollable screen was quite white on both sides. There is a black inner layer, a woven fabric outer layer, and a matte rubbery outer layer. I was projecting on the matte side when I took the screen shots found here.

Today I noticed that the same store (Fabricland in Ottawa) had two different rolls of BOC with an inner black layer. This time I noticed the one that did not look very white actually has a very white matte side. The fabric side is off white and that made me chose the other roll last time. This time I accidentally folded the material back and realized the matte side is quite white. I also noticed there were some other rolls of BOC that did not have the inner black layer and they were not as thick and strong.

At Rockland Textiles, here in Ottawa, they had yet another type of BOC with the inner black layer, it had the usual fabric outer layer but the other side that is typically a rubbery matte white had a very fine nap to it. I have no idea how it would look as a screen.

The point is, that we talk about BOC on these DIY screen forums as if it is a known quantity. I don't think that is true. I have seen a half dozen different BOC fabrics in just two different stores lately.

For anyone looking to make a BOC screen, I would suggest looking for BOC with the inner black layer and one side that is smooth, rubbery, and quite white looking. It will probably be the more expensive of the selection available but I think the little extra you will pay is worth it.

[tiddler]

Working Drawings

Here are the drawings that I am currently working from:



Click the images to see the full size jpg.

I'm still not completely happy with the tab spacing. The hooks for the masking panels must be where they are and that creates a bit of an obstacle for the screen tension tabs. There just seems to be too much room between the top/bottom bars and the first tab location. It might look better, and still work fine with 4 tabs instead of the five I have shown. I'll have to mull this over a bit more.

I spent Sunday afternoon wandering through Home Depot, RONA, and Canadian Tire looking for hardware that would look nice and suit my purposes. The hardest thing to find was some sort of hook for the the side tension straps. I thought I could use the L shaped screw in hooks but they were way too long and the hook part was too short. I did find some little plastic parts used for drapes that will work.

I was looking for some of those rubber feet that use a screw to hold them in place but could not fins anything suitable. I finally settled on some of the nail on feet. These will be used as stops for the side bars.

I grabbed some of the nylon iron on patches from the fabric store. I picked up some staples and carpet tape at Canadian Tire. I could not find anything better than the hook and eyes that I already have, and I had a bunch of brass 1" hooks already. So I think I have all the hardware I need.

While I was driving around it occurred to me that you could add some drapery material to the top bar that would form a valance that would effectively hide the screen when rolled up. I had a look for some short valance curtains but did not like anything I saw. Then I remembered the last comforter we bought came with a bed skirt. I will use that to show how this could work. If we don't like it, it will be easy enough to remove.


The Building Plan

I think it would be best to paint the top and bottom bars before assembling the screen. I will have to wait until the screen is attached to the top and bottom bars to see how long to cut the side bars. Painting them will have to wait. I have decided to rip the side bars down to 2" to allow more room for the gap between the edge of the screen and the side bars, and to make the side borders a bit wider. Once the side bars are cut to length I will paint them. I was thinking I should consider making a sort of foot for the top and bottom of the side bars. This would be to make them wider where they come in contact with the top and bottom bars. The wider they are the stable they will be. The bottom bar has a tendency to twist and I am hoping this would stop that. I also think it would be wise to put some felt on the ends of the side bars so they don't scratch up the paint on the top and bottom bars.

I promised my wife that this little project would not include any painting in the house this winter. She is very allergic to latex and painting has quite an effect on her. Especially in the winter with the house sealed up tight. I was granted permission to use some space at work for the painting. So the top and bottom bars will have to come to work and wait until I have a weekend free for the painting.

Meanwhile I will start preparing the screen material. Attaching the tabs and documenting the process so it can be duplicated if the results are good. The same goes for the masking panels. Unfortunately I made that first mock up mask before I decide to widen the screen borders so I will have to get more material and get the exact name of the material also.

I have not decided if I will paint the screen yet. The odds are whoever ends up taking this off my hands will probably not be installing it in a dedicated theater so a white screen is really not ideal for a typical family or living room. I have a quart of Black Widow made up using the Behr 4850 and this would be a good use for it. On the other hand, I have never painted up a whole screen with a neutral gray + satin polycrylic mix. I am curious to see what it looks like on a full size screen. Oh well that is a couple of weeks away, lots of time to consider that decision.

[tiddler]

Alternate Tab Spacing Plan



I think this looks more reasonable. The original proof of concept version only had three tabs and it was very flat so 4 tabs should be plenty.

[tiddler]

rengate, on Jan 25 2009, 02:41 AM, said:

So what kind of material is that black stuff? Is it felt?

The material that I will be using for the masking flaps is called "Cotton Pique". The clerk said the Pique referes to the pattern in the weave. This material has a diamond patter in the weave. She said some have circles and other shapes. Here is a link to Wikipedia.

What really matters, is that it is not stretchy and there is very little sheen to it. I think the lack of sheen is due to the cotton. The weave is probably what makes it less stretchy. It is not likely that you would find this exact material at any given fabric store. Look for something similar in weight and strength to blue jean material but very black with as little sheen as you can find.

[tiddler]

DIY Rollable/Reversible/TabTension Screen Build

Symmetry == Reversible

I was thinking that my roll-able screen is symmetrical side-to-side, top-to-bottom, and front-to-back. That means you could use the matte side of the BOC for a white screen. Then paint the back side with a gray mix.

It would be easier to flip over because you would simply lift the current bottom bar up and attach it to the ceiling mount. Then unhook and lower the current top bar, thus flipping the screen over.

So what we have is a roll-able screen that is tab-tensioned, has integrated 2.39:1 masking, can be a dual white/gray screen, and so far the only special tool required is a router and a couple of bits.

I am using BOC but there is no reason why you could not use canvas or any other suitable material to get a much larger screen. The only limiting factor is lumber length.

This post has been edited by tiddler: 02 February 2009 - 01:25 PM

[tiddler]

DIY Rollable/Reversible/TabTension Screen Build

Preamble

I think I have worked out most of the building details for this design. I will be taking lots of photographs as I start to actually try to build this thing.

I will post these photos and some descriptions here in this thread. I will point out that this is the first time I have built this design so I would not say it is proven. I am confident from the various trials and experiments that it will turn out to be a reasonably attractive screen and that it will work very well. I just want to keep some record of my work and allow anyone who is eager to get started a chance to see what I am doing as I go.

Any posts containing information about the build will be titled as this one is. That way you can use the find feature in your browser to jump to the relevant posts. If it turns out to be a good DIY screen I will clean up all the documentation and present a thread that is much more coherent.

NOTE: The materials, parts, and methods I will use are not necessarily the best possible. I wanted to come up with parts that were easily found at a Lowes or Home Depot. I also wanted to avoid construction techniques that require a full blown wood shop. The only exception to that is the use of a router. Rounding corners uniformly with a radius of 1/2" to 3/4" is only really possible with a router. Otherwise I will try to use nothing more than a hand drill.


Elastic Tab Clips

I had envisioned using those right angle screw in hooks but found them to be too long in the shaft and too short in the hook for my purposes. I wandered around Home Depot for quite awhile before finding something I felt was suitable. What I found was Levelor Traverse Rod Carriers.


Click thumbnails to see full size.

When you combine this plastic gismo with a 1" drywall screw it makes for a nice low profile hook for the elastic loops to slip over.

This post has been edited by tiddler: 02 February 2009 - 01:24 PM

[tiddler]

DIY Rollable/Reversible/TabTension Screen Build

Side Bar Ends

I have mulled over several ways to anchor the side bars to the top and bottom bars. One way would be to cut a slot in the top and bottom bars that the side bars would slip into. Another more stable idea came from kramg. He suggested cutting a slot all the way through the end of the top and bottom bars. This slot would be 3/4" wide and 1 1/4" deep. The end of the side bars would then have a notch cut out leaving a piece 1 1/2" long and 1 1/4" wide. This would fit into the slotted end of the top and bottom bars. The notch of the end bars would still provide pressure separating the top and bottom bars while the longer piece in the slot would stabilize the top and bottom bars so they would not rotate. This is a superior design idea but it requires more than very basic tools and skills.

The idea I settled on was to have one or two pins that stick out of the ends of the side bars. The top and bottom bars would then have holes that these pins would fit into.

Once again I had to wander around Home depot for quite awhile looking for very common parts to use. I settled on some faucet washers. These are 1/2" outside diameter. When you stack two flat washers and one beveled washer you get a nice 1/2" diameter pin. The first photo shows the tools and parts I used. The other photos show how I assembled them.







The joint is reasonably stable and the rubber washers allow for less than perfect alignment. In the first photo you may have noticed a shorter screw with only one flat washer and one beveled washer. That may be long enough but I grabbed enough washers to go with the three washer stack.


Rounding Fabric Exit

I wanted to show that the edges where the screen fabric and masking flap fabric exit the sandwich bars should be rounded. The material will be repeatedly folded against this edge and therefore it should not be sharp.

Before Sanding Inside Edges:


After Sanding Inside Edges:


These photos do not show this very well though. It is the edge of each sandwich bar where they come together. This is where the screen fabric will be. As you roll the bar the fabric will be folded 90 degrees over that edge and if left sharp it could wear the material.

This post has been edited by tiddler: 02 February 2009 - 01:24 PM

[tiddler]

DIY Rollable/Reversible/TabTension Screen Build

Bar Preparation

I finished routering the pieces that make up the top, bottom, and side bars. I then sanded them and applied a thinned primer coat. This will make all the fibers of the wood stand up so I can sand them smooth. Another way to do this is to wipe down the wood with a damp cloth. The water will cause the fibers to stand up. Once the wood dries you then do a finish sanding.



I will wet sand with a fine sanding sponge as soon as I get a chance. Then I will apply a couple of coats of white paint to about 8" on the ends of each of the top and bottom bar halves. The center area will get painted with a matte black paint later. I will also paint the side bars white. Then I will paint the routered detail along the edges with a nice bright metallic gold to go with the brass hooks I will use to hang the screen.

The hard part is finding the time to get this done. I doubt I will be ready to assemble the screen this weekend. However I can start getting the masking flaps ready and cut the BOC in preparation for mounting it to the top and bottom bars.

This post has been edited by tiddler: 02 February 2009 - 01:23 PM

[tiddler]

DIY Rollable/Reversible/TabTension Screen Build

Metallic Gold Trim Painting

I finally finished the metallic gold trim painting on the bars.


Click thumbnail to see full size.

I used Folkart Metallic Inca Gold #676. It was the lightest brightest metallic gold I could find at Michaels. I wanted something that would be similar to the brass hooks I will be using.

It took two coats to get the gold to look uniform. I used a small artist's brush. Any excess paint that went outside the concave area was easy to wipe off with a damp rag. It took longer than I had imagined and I did not anticipate having to apply two coats.

I don't know if it was something in the paint or the eye strain from doing this fine painting but I ended up with a splitting headache by the time I finished each coat.

Tomorrow night I will start the assembly process. The first thing I will do is put the masking flaps together. I will also have to do some measuring and try to determine the length of the flaps. This is not quite as straight forward as you may think. I will have to take some guesstimates of material stretching into account. It would be best if the flaps were a bit longer than required but not too long. I will just have to make the best estimate I can and hope that I don't cut them too short.


Thoughts On Masking Flaps

I have decided that trying to guess the amount of stretch there will be in the BOC when tensioned is just that, guessing. Therefore I will fully assemble the screen without the masking flaps. I can tell from this photo of the slapco version that there could be quite a bit of lateral stretch. I also think there was 1/4 - 1/2" vertical stretch.



It looks like there could easily be as much as 1/2" of stretch on either side. Therefore I will cut the BOC 97" wide to allow for up to an inch of stretch laterally. If the BOC stretches to 98" wide then I will only have a maximum of 3" of space between the edge of the BOC material and the side bars. If it does not stretch that much then I will have less room for the image area. I am already thinking I should reduce the image area to 92"x54.75" to make the painting a little easier along the sandwich bars. It would still be slightly larger than 105" diagonal.

The point is that I am guessing and the only way to really know is to assemble the screen. Then I can see exactly how big the 16x9 image area should be to allow for reasonable borders on the sides. This will set the width which will dictate the height and also establish the length of the masking flaps.

The danger with guessing is that I will cut the masking flaps too short and then they will be useless and I will have wasted a lot of money and time on them. It will be better to take the time to assemble the screen without them and then get accurate measurements.

This post has been edited by tiddler: 08 February 2009 - 09:56 PM

[tiddler]

DIY Rollable/Reversible/TabTension Screen Build

BOC Material Preparation & Mounting

I was looking for a long piece of shelf or MDF to use for cutting material etc. I found 1/2" x 12" x 97" pieces at Home Depot for something like $4. You can see it under the top edge of the BOC in this first photo:



As you can see the roll of BOC I had was way too long to work with, so I first did a rough cut to get it down to a size I could manipulate easier.

The piece of MDF I purchased was 97" long so it made a good guide for cutting the BOC. By folding the BOC over so that the top and bottom edge are perfectly aligned you can mark the exact place to cut top and bottom to get a square edge.



Once you have a starting cut top and bottom you can use a straight edge and knife to cut the sides.

[tiddler]

DIY Rollable/Reversible/TabTension Screen Build

BOC Material Preparation & Mounting

The next thing was to mark the center of the top and bottom edge for alignment to the mounting bars. I also wanted to mark the center of the sides to locate the tension tabs.



To locate the center of the top and bottom I folded the BOC so the side were aligned. The fold was then the center which I marked with a pencil.



The procedure is the same for the sides except you fold the BOC so that the top and bottom edge are aligned. Once again I marked the center with a pencil.

[tiddler]

DIY Rollable/Reversible/TabTension Screen Build

Elastic Tension Tabs

From the center mark on the sides of the BOC I marked 8.5" intervals. This is where the 5 tabs will be attached.



The next step was to prepare the elastic to make the tabs. I cut the elastic into 6" pieces. That allowed an overlap of 1" on each end 2" of elastic extending into the gap between the side of the BOC and the side bar.

I used the lighter to seal the threads after I cut the elastic. You just have to pass the flame over the end of the cut elastic to melt all the threads together.