Nine Foot Wide 21:9 AT Spandex Screen with Anamorphic Prism Lens - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 3Likes
  • 1 Post By scarabaeus
  • 1 Post By scarabaeus
  • 1 Post By scarabaeus
 
Thread Tools
post #1 of 9 Old 02-11-2019, 06:42 AM - Thread Starter
Advanced Member
 
scarabaeus's Avatar
 
Join Date: Nov 2006
Location: San Leandro, CA, USA
Posts: 862
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 431 Post(s)
Liked: 434
Nine Foot Wide 21:9 AT Spandex Screen with Anamorphic Prism Lens and Velvet Frame

For my basement movie room, I was looking to go with a good sized 21:9 screen, to complement my 55" OLED. Ideally, it would be hanging in front of the TV, and be able to be moved out of the way.

I had gotten a broken Optoma HD27HDR in return for some speaker installation and wire fishing help from a co-worker. Brand new, it didn't turn on anymore, and she had already gotten a replacement, so I gave fixing it a shot. Eventually, simply removing the lamp assembly and putting it back in resolved the issue. Yay, free projector! Let's put it to use for some immersive cinemascope experience.

I based my frame design on this one: https://www.avsforum.com/forum/110-d...een-build.html , where I had posted an earlier version of this report.

Thanks to @Aberk for the lead work. I based a 108" x 45" screen on his description, that's a 117" diagonal size at 2.40:1. The 16:9 center portion is 80" x 45", with a 92" diagonal.

Material:
I cut the wood to size (2 X 45", 2 X 38", 2X 101") and assembled it with 4 Kreg screws at each joint, adding wood glue. I started by making 2 "F"-shaped pieces, which makes squaring the final joints easier by allowing for a bit of sideways shift for the inside pieces.







Next, I glued the quarter round to the front, and then rounded the rear edges with 1/4" roundover bit on a hand router. This helps when spanning the spandex.





Above you can also see the small gap I had to patch with wood filler. This was due to my crappy job of keeping my circular saw cuts perpendicular, and the Kreg joints faithfully adhering to that crooked angle.



After that I sanded and stained the wood deep black, preparing with pre-stain for even absorption. This is super easy with a staining pad, but wear latex gloves! The smell goes away after a few days.



Then I attached the eyelet screws, pre-drilling with a 13/64" bit. I did both top and bottom, because I was planning on some elaborate rigging to hoist the screen to the ceiling, but that is still WIP. For normal hanging, just the top ones are needed, though that causes a slight slant forward of the screen. I positioned them at the edges of my 16:9 area, 14" in from the edge, for esthetic reasons.



For the ceiling, I had to go into the joists at 45 degrees, because they were continuing joist, and offset on the two sides of a beam. I then plastered the eyelets halfway in, making them barely noticeable.










bubbrik likes this.

Last edited by scarabaeus; 02-23-2019 at 12:18 PM.
scarabaeus is offline  
Sponsored Links
Advertisement
 
post #2 of 9 Old 02-11-2019, 06:43 AM - Thread Starter
Advanced Member
 
scarabaeus's Avatar
 
Join Date: Nov 2006
Location: San Leandro, CA, USA
Posts: 862
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 431 Post(s)
Liked: 434
Spandex

For the spandex, I followed the guidance here: https://mehlau.net/video/diy-spandex-projection-screen/

I went with a 5% stretch, so with a 108x45 screen, adding 1 1/2" for the edge and another 2" to cover the back of the frame, I cut the spandex to (108" + 2 * 1.5" + 2 * 2") * 0.95 = 115" * 0.95 = 109.25" by (45 + 2 * 1.5" + 2 * 2") * 0.95 = 52" * 0.95 = 49.4". I rounded it up to 110" x 50", because I can't cut spandex that precisely.

Attempting to do it like a professional and cutting it with a rotary knife on a cutting mat did not work so well. I ended up just marking the spandex with chalk, and simply cutting it with scissors.



Same with the white, but since that was just a yard and a half of 120" wide, I put that sideways.



Then I layered the black on top of the white, positioned the frame over it, and started stapling.








I started in the middle of a long edge, grabbed the edges of both layers tightly, and pulled them about 2 inches onto the back of the frame. For the first, main, points, I used three staples each, but only single staples for the later ones. Next I did the same on the middle of the other long edge, then the centers of the two shorther edges. After that I did the corners, alternating diagonally across. Try to tuck the fabric in neatly at the corners. At this point, the screen should already be free of wrinkles.




Then just continue at the halfway points between staples, always alternating opposite sides. I did a few rounds of that, ending up with 64 and 24 staple points at the long and short edges.



I spare you my misguided attempts at rigging the screen with pulleys, to make it fold up onto the ceiling, and just show you the simple rope to hang it in front of my 55" OLED.






Sorry about the mess.



First, I set up the projector (Optoma HD27HDR, with a 1.5 TR) to use the 16:9 center area.




Attached Thumbnails
Click image for larger version

Name:	021_Projector.jpg
Views:	242
Size:	75.4 KB
ID:	2524082   Click image for larger version

Name:	020_Test_Picture.jpg
Views:	241
Size:	97.1 KB
ID:	2524084   Click image for larger version

Name:	019_Hanging.jpg
Views:	245
Size:	88.0 KB
ID:	2524086   Click image for larger version

Name:	018_Rope.jpg
Views:	241
Size:	59.5 KB
ID:	2524088   Click image for larger version

Name:	017_stapled.jpg
Views:	237
Size:	80.6 KB
ID:	2524090  

Click image for larger version

Name:	016_first_eight_staplings.jpg
Views:	245
Size:	80.4 KB
ID:	2524092   Click image for larger version

Name:	015_frame_on_top.jpg
Views:	242
Size:	81.8 KB
ID:	2524094   Click image for larger version

Name:	014_spandex_layered.jpg
Views:	243
Size:	73.0 KB
ID:	2524096   Click image for larger version

Name:	013_spandex_white.jpg
Views:	244
Size:	69.9 KB
ID:	2524098   Click image for larger version

Name:	012_spandex_black_cut.jpg
Views:	246
Size:	87.4 KB
ID:	2524100  

bubbrik likes this.

Last edited by scarabaeus; 02-23-2019 at 12:15 PM.
scarabaeus is offline  
post #3 of 9 Old 02-11-2019, 06:43 AM - Thread Starter
Advanced Member
 
scarabaeus's Avatar
 
Join Date: Nov 2006
Location: San Leandro, CA, USA
Posts: 862
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 431 Post(s)
Liked: 434
Anamorphic Prism Lens

Then, I got the "french" prisms from Surplus Shed in Pennsilvania, and built a small wood holder, lined with black felt.

Prism threads:
https://www.avsforum.com/forum/174-d...m-article.html
https://www.avsforum.com/forum/174-d...ch-prisms.html

The essential drawings to construct a holder are these (full size attached below):



There are provisions in the measurements that allow for a lever to switch between pass-through and expansion, but I just did a fixed expansion version. (For the lever, attach a rod to the points marked along the center line of the prism, designated in the last diagram by the red distance measurements from the rotating points. That makes the prisms rotate in unison between the two end positions for pass-through and anamorphic)

They arrived nicely packaged:





I simply glued black felt with wood glue to some redwood I had left over, and placed the prisms according to the drawings. Just being held in place by the compression of the top cover, I can still shift them around slightly to fine-adjust. Just be careful not to tilt them when pushing, since that makes the pincushion distortion worse.





For now, I simply placed the box in front of the projector, but at some point I might do something more permanent.








To format the signal, I run all my video through the Oppo BDP-203, and set the output aspect ratio to 21:9. More on that later. That allows me to keep the prism in place for all cases, though I lose a bit of horizontal resolution in 16:9 mode. But I mainly watch cinemascope movies on this contraption anyways.



As for image quality, the screen is great! Acoustically transparent, and even my IR remote commands come through to the sensor in the rear. The Prism causes a bit of chromatic aberration on the sides, and some minor pin cushion distortion at the bottom, but that is not noticeable in normal content. The Rainbow effect of the projector, however... Might have to look for a 3 chip projector at some point.



Next, I added a black velvet frame around the screen, to capture some of those errant diffractions and crooked edges caused by the prisms.
Attached Thumbnails
Click image for larger version

Name:	PassthroughPrismholder.jpeg
Views:	32
Size:	74.3 KB
ID:	2524106   Click image for larger version

Name:	PassthroughCase.jpeg
Views:	31
Size:	45.1 KB
ID:	2524108   Click image for larger version

Name:	PassthroughPrisms.jpeg
Views:	38
Size:	77.6 KB
ID:	2524110  
bubbrik likes this.

Last edited by scarabaeus; 02-11-2019 at 11:36 AM.
scarabaeus is offline  
Sponsored Links
Advertisement
 
post #4 of 9 Old 02-11-2019, 06:45 AM - Thread Starter
Advanced Member
 
scarabaeus's Avatar
 
Join Date: Nov 2006
Location: San Leandro, CA, USA
Posts: 862
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 431 Post(s)
Liked: 434
Velvet Foam Frame

Since it's nearly impossible to match the projected image with the screen frame, in particular due to some pincushion distortion by the anamorphic lens, and the fact that the projector adds a very dim frame of about 50 pixels around the image area, I decided to add a frame to capture those errant photons. For that, black velvet is the ideal absorption material. I just needed a way to add about 4 inches of that around my spandex screen.

I decided on using some foam material, and wrap that with the velvet. A durable material presented itself in Low-Density Poly-Ethylene (LDPE) foam, as used for packaging delicate electronics and such. I found a rather large sheet, 1" thick, at a local packing supply place.

Materials:
Next, I had to figure out how to wrap velvet about the foam. To figure out the shape of such a wrap, I made a small paper model:





Then I started on the foam, by cutting 4 inch wide strips. For that, I used a simple kitchen knife, and level as a guide for the blade, to keep it perpendicular. This wasn't ideal, but worked for the most part.





Polyethylene (PE, HDPE, LDPE) and Polypropylene (PP) are a b*tch to glue, as I learned when I built kites with Tyvek when I was a teen. Hot Glue seems to work, as does any form of heat welding, and (expensive) specialty glues. I decided on a mechanical solution, good old dove tails. First I made a template out of a plastic sheet, and then used that to make the cuts with the kitchen knife.






That got me a frame with a nice fit around my screen. The bottom was hanging down a bit, but that was a solvable problem.



Then I created a more detailed pattern for the velvet. I needed about 10 inches of velvet to wrap around the 4" x 1" foam beams, leaving about a 2" gap in the back for tensioning. Here's a PDF scan of the pattern, printing in "actual size" should maintain the scale.



The velvet is very prone to fraying. To avoid that, I used pinking shears, where the zig-zag pattern prevents fraying. I cut 4 strips, 10 inches wide, and about 10 inches longer than the edges of my screen.








The velvet is very delicate. You can see the dents I left on one strip when I kneeled on it during cutting. This has been a learning experience for me, please try to avoid my mistakes.


Then I marked the nominal length on the strips. I did one line about 5 inches from one end, then measured the exact length of each screen edge and marked the second line. For marking, I used a chalk wheel pen; fortunately my wife is into sewing and has all of these cool tools. Then I folded the strips in half, back to back, and pinned the two marked lines together.








Next, I traced a couple of cut patterns from the original, and stapled those to the velvet. I set two stacked ends on top of each other, so 4 layers of velvet alltogether. Make sure to align the length markers of the pattern with the marked line on the fabric. Also, don't staple through the part of the fabric that will be used, only what gets cut away. The staples help to keep the slippery fabric layers aligned. Then cut around the lines, again with pinking shears.









For the next step, I made a sewing template out of a long piece of card board. This helps to keep the pattern straight, and the corner at 90 degrees.



Now the seam. This is a lot of work, as it goes all the way around the edge, and on both sides. Fold in half an inch, then fold it again, and put a pin in the center every 3 to 4 inches. Sew as close to the inner fold as possible, about 1/16" in.






Now for the actual corners. Put one end of a long edge piece of velved face-to-face onto one end of a short edge piece. Align the length markers precisely, and pin them together. Use the cardboard template to mark the sew line, notice where the pattern aligns with the length marker. Pin the seam allowance, but also leave the pins in the length line for extra stability. (slippery velvet!)









Sew along the marked sew line, then trim the seam allowance, and clip the corners. If you want to go overboard (and who here wouldn't...), you can turn the corners with thread, See "Getting sharp corners using a thread tail" on this page:
https://closetcasepatterns.com/sewin...alle-sewalong/










Removing the pins from the length line and turning the fabric right-side out shows how the corners will look.






Then repeat with the other three corners, but make sure at the last corner that there is no twist in the overall frame wrap!
Attached Thumbnails
Click image for larger version

Name:	031_frame_teaser_large.jpg
Views:	84
Size:	817.4 KB
ID:	2524112   Click image for larger version

Name:	033_paper_model.jpg
Views:	161
Size:	90.1 KB
ID:	2529826   Click image for larger version

Name:	034_paper_unfold.jpg
Views:	161
Size:	101.2 KB
ID:	2529828   Click image for larger version

Name:	035_foam_sheet.jpg
Views:	164
Size:	84.1 KB
ID:	2529832   Click image for larger version

Name:	036_foam_cut.jpg
Views:	169
Size:	88.3 KB
ID:	2529834  

Click image for larger version

Name:	037_dove_tail_template.jpg
Views:	161
Size:	73.5 KB
ID:	2529836   Click image for larger version

Name:	038_dove_tail.jpg
Views:	158
Size:	88.9 KB
ID:	2529838   Click image for larger version

Name:	039_first_fit_check.jpg
Views:	159
Size:	82.8 KB
ID:	2529840   Click image for larger version

Name:	040_pattern.jpg
Views:	161
Size:	98.1 KB
ID:	2529842   Click image for larger version

Name:	041_velvet_cut_pinking_shears.jpg
Views:	152
Size:	64.6 KB
ID:	2529852  

Click image for larger version

Name:	042_velvet_strips.jpg
Views:	158
Size:	65.3 KB
ID:	2529854   Click image for larger version

Name:	043_velvet_length_mark.jpg
Views:	157
Size:	99.7 KB
ID:	2529856   Click image for larger version

Name:	044_pinned_back_to_back_folded.jpg
Views:	159
Size:	89.2 KB
ID:	2529858   Click image for larger version

Name:	045_staple_cut_pattern.jpg
Views:	156
Size:	101.3 KB
ID:	2529864   Click image for larger version

Name:	046_cutting.jpg
Views:	157
Size:	99.8 KB
ID:	2529866  

Click image for larger version

Name:	047_finished_cut.jpg
Views:	160
Size:	80.7 KB
ID:	2529868   Click image for larger version

Name:	048_sewing_template.jpg
Views:	155
Size:	86.0 KB
ID:	2529870   Click image for larger version

Name:	049_fold_pin_seam.jpg
Views:	159
Size:	93.7 KB
ID:	2529872   Click image for larger version

Name:	050_seam_stitch.jpg
Views:	157
Size:	83.2 KB
ID:	2529878   Click image for larger version

Name:	051_sewing_marking.jpg
Views:	155
Size:	75.6 KB
ID:	2529880  

Click image for larger version

Name:	052_template_alignment.jpg
Views:	153
Size:	49.8 KB
ID:	2529882   Click image for larger version

Name:	053_marked_and_pinned.jpg
Views:	156
Size:	82.8 KB
ID:	2529884   Click image for larger version

Name:	054_sewn.jpg
Views:	162
Size:	118.3 KB
ID:	2529886   Click image for larger version

Name:	055_trimmed.jpg
Views:	162
Size:	114.4 KB
ID:	2529888   Click image for larger version

Name:	056_trim_detail.jpg
Views:	156
Size:	153.0 KB
ID:	2529890  

Click image for larger version

Name:	057_corner_right_side_out.jpg
Views:	157
Size:	105.8 KB
ID:	2529898   Click image for larger version

Name:	058_corner_rear_side.jpg
Views:	156
Size:	107.6 KB
ID:	2529900   Click image for larger version

Name:	059_wrap_around_foam.jpg
Views:	148
Size:	81.5 KB
ID:	2529902   Click image for larger version

Name:	060_misguided_attempt_one.jpg
Views:	151
Size:	96.4 KB
ID:	2529904   Click image for larger version

Name:	061_misguided_attempt_two.jpg
Views:	156
Size:	94.9 KB
ID:	2529906  

Click image for larger version

Name:	062_lacing_concept.jpg
Views:	155
Size:	105.5 KB
ID:	2529908   Click image for larger version

Name:	066_cutting_notches.jpg
Views:	152
Size:	112.2 KB
ID:	2529910   Click image for larger version

Name:	067_pulling_thread_through_seam.jpg
Views:	155
Size:	94.5 KB
ID:	2529912   Click image for larger version

Name:	068_securing_corners.jpg
Views:	154
Size:	99.4 KB
ID:	2529914   Click image for larger version

Name:	069_lacing.jpg
Views:	152
Size:	97.4 KB
ID:	2529916  

Click image for larger version

Name:	070_kitty_help.jpg
Views:	157
Size:	59.4 KB
ID:	2529918   Click image for larger version

Name:	071_lacing_continued.jpg
Views:	154
Size:	105.9 KB
ID:	2529920   Click image for larger version

Name:	062_mind_the_gap.jpg
Views:	155
Size:	93.7 KB
ID:	2529942   Click image for larger version

Name:	064_foam_attempt_two.jpg
Views:	152
Size:	97.8 KB
ID:	2529944   Click image for larger version

Name:	065_foam_frame_pieces.jpg
Views:	152
Size:	81.6 KB
ID:	2529948  

Click image for larger version

Name:	063_corner_over_exposed.jpg
Views:	155
Size:	113.6 KB
ID:	2529952   Click image for larger version

Name:	072_frame_fitting.jpg
Views:	155
Size:	66.4 KB
ID:	2529954   Click image for larger version

Name:	073_rear.jpg
Views:	156
Size:	75.1 KB
ID:	2529956   Click image for larger version

Name:	074_support_wire_hooks.jpg
Views:	155
Size:	59.5 KB
ID:	2529958   Click image for larger version

Name:	075_final_cleanup.jpg
Views:	157
Size:	71.6 KB
ID:	2529960  

Click image for larger version

Name:	076_final_result.jpg
Views:	167
Size:	84.3 KB
ID:	2529962   Click image for larger version

Name:	077_light_capture.jpg
Views:	162
Size:	69.9 KB
ID:	2529964  
Attached Files
File Type: pdf 032_corner_pattern.pdf (419.0 KB, 4 views)

Last edited by scarabaeus; 02-23-2019 at 10:44 AM.
scarabaeus is offline  
post #5 of 9 Old 02-11-2019, 06:46 AM - Thread Starter
Advanced Member
 
scarabaeus's Avatar
 
Join Date: Nov 2006
Location: San Leandro, CA, USA
Posts: 862
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 431 Post(s)
Liked: 434
... Velvet Foam Frame continued ...

Assemble the foam frame on a flat, clean surface and wrap the finished velvet around it. I had to experiment a bit to figure out how to close it up in the back so that it maintains enough tension. This will both prevent wrinkles in the velvet, and hold the dove-tailed foam together. My first two attemps, with simple thread, and curtain clips, went nowhere.










I then experimented a bit with some scrap fabric and came up with this:
  • Cut triangular notches, spaced about 4 inches, into the seams on both sides along the edges, staggered evenly between inside and outside seams.
  • Run kevlar string (used for kites, does not stretch very much) inside each seam, forming a larger and smaller rectangle. A crochet needle helps. Secure the corners of the rectangles together in the corners with a small loops.
  • Then zig-zag another kevlar string around those two framing strings, from notch to notch. I started in the center of each edge, and threaded the string loosley until I reached the corners.
  • Then I started again in the centers, and tightened the zig-zag string, similar to how to lace a long boot, but with only one lace.
  • After tightening, I knotted the ends to the corner loops, and trimmed off any extra string.



















(My cat decided to help with the string...)




A few notes on the kevlar string. I used 380 pound string, because it had a good diameter to handle, but less (120 pound or so) should be just as good. The kevlar has very little stretch, but is also notorious for slipping, and difficult to keep knotted. When you cut it, you have to make simple knots at each end to prevent fraying. To join two ends together, the fisherman's knot works best.



Along the way I realized a few things that were not clear to me before. When I first tried to fit the frame with the wrap onto my screen, I realized that the layers of fabric (velvet and spandex) add up to quite a thickness. I was left with a sizable gap:




Also, the dovetail corners were not as sturdy as I would have liked. So I did a second foam frame, this time with the connections along the edges, and adding 1/2" along each edge over the length of the wood frame under the spandex.







This worked out much better. The velvet can still be sized without the extra 1/2 inch, it stretches and that avoids wrinkles. Though I had some rip-out of the inner seam in the corners, I should have trimmed less of the seam allowance.

Here is the result:











To pull the frame towards the screen where it had gaps, I fashioned some simple wire hooks in the back.




Here's a picture of a corner, overexposed to show the seam. The chalk lines from the length marking are also still slightly visible, but they came out when vacuuming. Also, another corner showing how much a bright white line is absorbed by the velvet. The chromatic aberration is from my anamorphic prism.











The frame makes the movie watching experience so much better, I'm glad I spent all this effort on the frame. Maybe I'll add some motorized masking for 16:9 next.




Scaling with an Oppo 203

My connections are a bit elaborate, because I still have the OLED behind the projection screen. Also, with the anamorphic prism, I need to use a scaler. The Oppo 203 does a great job with that, it has a dedicated "21:9" mode that keeps all menu items and sub titles from Blu-rays on the screen. For external content from the HDMI input that does not quite work out so well, it has some clipping at the top and bottom, naturally.



I connect the main out of my AVR (Denon 4400) to the OLED, to allow for ARC, and the secondary AVR out to the Oppo HDMI input. If I watch the projector, I connect the Oppo main out to the projector, and the audio-only HDMI out to the AVR's Blu-ray input.


For when I use the OLED, I take down the screen, unplug the projector from the Oppo, and move the cable leading to the AVR from the audio-only HDMI output to the main out of the Oppo. This way I only have to plug at the back of the Oppo (easy access), but I'm still looking for a switch-based solution. So far one supposed UHD60 capable switch wasn't.


As for scaling content, the Oppo offers three modes: 16:9, 21:9 and full. The "full" one is useless, it just stretches 16:9 content horizontally with plenty of distortion. The 21:9 mode is cropping the center 3/4 of 16:9 content, and blows it up onto the whole screen. That is the portion usually taken up by "Scope" content: 2.35:1, 2.39:1 and 2.40:1 (all three ratios are simply interchangeable terms nowadays, and often misused). Early Cinemascope movies in 2.55:1 will still have slim letterbox bars. I also use this for movies in 2.20:1, though that crops them a bit.



The 16:9 setting is for all other content with aspect ratios of less than 2.20:1, it leaves the side portions of the screen blank and only used the 16:9 center portion. This might not be ideal for all content. 1.85:1 movies still have slim letterbox bars, in addition to the side bars which you have with 16:9 content. 2.00:1 (Netflix) is the worst, either you lose a bunch of content at the top and bottom with 21:9, or you have some serious windowboxing at 16:9.


Also, the Oppo does not have extra aspect ratio modes for 4:3 content (full frame DVDs). If you have old non-anamorphic (not "enhanced for widescreen") DVDs with 1.85:1 or 2.40:1 content, those are not scaled correctly.

Last edited by scarabaeus; 02-23-2019 at 09:33 PM.
scarabaeus is offline  
post #6 of 9 Old 02-11-2019, 07:29 AM
Member
 
jencas's Avatar
 
Join Date: Jul 2004
Location: Voluntown, CT
Posts: 56
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Liked: 21
If you're going to hang this from the ceiling with no other attachment points, you may find it does not hang vertically unless you have just by chance installed the eye-screws in the frame top at the exact center-of-gravity of your asymmetric (front to back) frame. Been there, done that.

Rex

Last edited by jencas; 02-11-2019 at 07:33 AM.
jencas is offline  
post #7 of 9 Old 02-11-2019, 09:18 AM - Thread Starter
Advanced Member
 
scarabaeus's Avatar
 
Join Date: Nov 2006
Location: San Leandro, CA, USA
Posts: 862
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 431 Post(s)
Liked: 434
Quote:
Originally Posted by jencas View Post
If you're going to hang this from the ceiling with no other attachment points, you may find it does not hang vertically unless you have just by chance installed the eye-screws in the frame top at the exact center-of-gravity of your asymmetric (front to back) frame. Been there, done that.

Indeed, it leans forward ever so slightly. This is not much of a problem in my case, as it angles the screen at the eye line of viewers sitting on the couch.


To make it perfectly vertical, I could either add counterweights to the bottom rear of the frame, or add tensioning ropes at the bottom and anchor them on the floor, or add stand-off rods towards the back wall. Not that I'd need that, but neither of which would be a good solution for me.
scarabaeus is offline  
post #8 of 9 Old 02-11-2019, 09:31 AM
Member
 
jencas's Avatar
 
Join Date: Jul 2004
Location: Voluntown, CT
Posts: 56
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Liked: 21
Quote:
Originally Posted by scarabaeus View Post
Indeed, it leans forward ever so slightly. This is not much of a problem in my case, as it angles the screen at the eye line of viewers sitting on the couch.


To make it perfectly vertical, I could either add counterweights to the bottom rear of the frame, or add tensioning ropes at the bottom and anchor them on the floor, or add stand-off rods towards the back wall. Not that I'd need that, but neither of which would be a good solution for me.
I used adjustable stand-off rods since it was a permanent installation. I had to push my screen bottom forward.

If you leave it angled, you also need to angle your projector to match or else the image will be key stoned.

Rex
jencas is offline  
post #9 of 9 Old 02-23-2019, 10:19 AM - Thread Starter
Advanced Member
 
scarabaeus's Avatar
 
Join Date: Nov 2006
Location: San Leandro, CA, USA
Posts: 862
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 431 Post(s)
Liked: 434
I finally completed my build report for the velvet frame, and completed the scaling section in posts 4 and 5.


Have a great weekend!
scarabaeus is offline  
Sponsored Links
Advertisement
 
Reply DIY Screen Section

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off