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Discussion Starter · #1 · (Edited)
I am long overdue in documenting my work-in-progress plan to build a DIY 4-way motorized masking system and screen frame intended for variable image sizes and aspects up to immersive proportions. Specifically, I plan to allow for seating distance-to-screen-dimension ratios as close as 1.7x screen height. For my seating distance of 8.5 feet, the usable screen area will be about 124"-wide x 60"-tall (2.07-aspect). I have severe limitations on image size due to the 10' depth of my room, and despite folding the light path with a first surface mirror I will be using an ISCO IIIL to achieve enough width for scope content.

Viewing Distance to Image Height Ratio || 2.35:1 || 16:9
2.0x || 52"x124" || 52"x93"
2.4x (casual or low quality content) || 43"x103" || 43"x77"
1.7x (IMAX and some variable-aspect content) || NA || 60"x107"

My plan is to build the screen frame and the masking frame using 80/20 t-slotted extruded aluminum framing. The t-slotted frames are ideal for the masking system as they provide a perfect channel for the mask supports to travel. The masking will be on rollers driven by quiet Somfy Sonesse 30 RS485 motors that provide variable speeds, multiple programmed stop points, etc.

Status Updates:

[2016 Nov 1] I sold my Falcon 100"-wide 2.35:1 AT screen two weeks ago, time to finalize the design and build this new screen! In the mean time I'm using an old paint-stained bedsheet tacked to my wall which is passable and has allowed me to play with image sizes; I definitely enjoy the 2.0x image height size for a lot of material but also sometimes find I need to go down to 2.4x for some content -- thus validating to me the need for 4-way variable masking. Currently evaluating other sources of extruded aluminum, e.g. Bosch Rexroth, Misumi, and co-designing a new mounting system for my two projector + mirror setup since the current ceiling mount vibrates significantly when the clothes washer/dryer are in use.

[2016 April 29] Screen size has been finalized to 120" x 60". I recently acquired a used 1.42x ISCO anamorphic lens on the cheap (larger than an ISCO IIIL) that should allow me to fill the planned 120-wide screen comfortably with any future projector (in combination with the mirror). Build is still on hold, however, as time is in short supply since I'm building a deck and will be enjoying the summer weekends with my kids in the great outdoors. I do have a sample of the Dreamscreen V6 material arriving soon; I expect it to be the material that I will use.

[2016 Jan 22] screen build is on hold until I determine which size screen to build: I'm waiting on a polished 1/4-wave float glass mirror sample to see if it has artifacts (my current 4-6 wave float glass mirror has draw line artifacts) or if I'll be limited to using a Navitar lens which will limit me to ~102" wide


Table of contents:
  1. link-to-parts-list
  2. link-to-frames-design
  3. link-to-construction-photos
 

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Discussion Starter · #2 · (Edited)
Parts List

Attached current parts list. Needs revision if I decide to go bigger than ~102"-wide screen
 

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Discussion Starter · #3 · (Edited)
Screen and Masking Frames Designs

Attached initial screenshots of Sketch-up plans, but not updated to the new width of 120". To be described.
 

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Discussion Starter · #9 ·
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Jeff - that looks like very sturdy alum extruded frame you are using, is Bosch Rexroth the source?
Plan is to use 80/20, that's what I've spec'd out parts list for so far -- any advantage to switch to the Bosch?
 

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Plan is to use 80/20, that's what I've spec'd out parts list for so far -- any advantage to switch to the Bosch?
how is this project going? i'm really interested. i'm trying to maximize my screen size w/o having to just use 16:9 or 2.35:1. thought, why can't i mix both and came up with the 120" x 60". hope it's going well.
 

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Discussion Starter · #11 ·
how is this project going? i'm really interested. i'm trying to maximize my screen size w/o having to just use 16:9 or 2.35:1. thought, why can't i mix both and came up with the 120" x 60". hope it's going well.
Updated the original post with current status (not much of an update unfortunately since I was stalled on confirming the screen size and was also distracted researching and buying a new SUV for the wife and kids).
 

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Discussion Starter · #12 · (Edited)
Quick update: I ordered the black extruded aluminum for my screen frame and masking frame on 11/22 and it shipped today 12/5 via freight! I ended up ordering direct from Misumi instead of 80/20 saving about 25% on the total cost for the pre-cut and machined aluminum, connector/screw hardware, and shipping. Through the end of December Misumi is offering 30% off orders for 30 days when you sign up with a new account. Where the savings became particularly interesting was that despite ordering some extrusions that are ~11.5 feet long (order total weight of ~100 pounds) the shipping on the entire order was only $62 (shipping from IL to OR).

The order total cost was about $900 shipped excluding the 80/20 container hanger profile that I will be using for the masking bars and for french cleats to attach to the wall; unfortunately Misumi did not have a similar product. The 145"-long container hanger profiles (5x ~$17) were ordered from a local 80/20 distributor; instead of paying freight on these I asked that they simply add 5 units to their next stock order so shipping will be free to their location but I'll just need to wait for those to come in within the next few weeks or a month, then I just need to rent a u-haul to bring it home (or find a friend in the Portland area with a truck that can handle the 12 foot material!).

A few details on the updated screen design: (note the Misumi material is all spec'd in millimeters and not inches but I'll use approximate inches here)

The screen frame outer dimensions 126" x 63" is constructed from qty 4 of extruded aluminum ~1.5" profile (2x 126" and 2x 60") and qty 2 ~1" profile 60" long for supports near the middle but inset ~0.5" so they won't be in contact the screen. I will still use Screen Tight along the outer edges (perpendicular to the screen surface) to attach my screen material (yet to finalized/ordered). On the rear I will attach ~12" segments of the container profile on the top segment to hang the screen (and a few on the bottom segment to keep the screen firmly against the wall but not supporting the weight).

The useable screen area without border profile visible behind the material is 123" x 60" with aspect ratio of 2.05.

Bordering the screen frame the masking frame will extend about 7" above/below/left/right of the screen. Thus the masking frame will be 140" x 77" with total screen/masking depth of ~4.75" exclusive of a decorative black border. The design is somewhat similar as pictured in post 3 but simplified as the corner is constructed using a single ~ 2"x4" profile instead of two pieces as shown.
 

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I hope you reach your dream. :)

Putting together a 4 way masking system was the single best decision in my entire home theater build.
(I don't have the full DIY chops to build from scratch so I did it for about $4,500 by combining two commercial systems: a Carada masking system for horizontal masking, and a somfy-driven curtain track with hanging black velvet panels for side masking. Works unbelievably well).
 
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Discussion Starter · #14 ·
I hope you reach your dream. :)

Putting together a 4 way masking system was the single best decision in my entire home theater build.
(I don't have the full DIY chops to build from scratch so I did it for about $4,500 by combining two commercial systems: a Carada masking system for horizontal masking, and a somfy-driven curtain track with hanging black velvet panels for side masking. Works unbelievably well).
Thanks for the kind words! Your posts on the use of a 4-way setup were much of my original inspiration. :)

My non-update: the masking/screen build saga is again on hold for the moment as I first want to get the remaining dusty construction done to version 2.0 of my room -- adding a soffit and basic coffered ceiling -- for the bass trapping, ceiling blackening, and for better lighting schemes. I'm still working out the details but plan to fill the area in between the coffered ceiling segments with acoustic treatments as well.
 

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I was going to go Carada 2 way masking and then they stopped making the product.

I would love to get in on the 30% discount but I am still clueless about exactly how to build the masking system despite looking at your parts list.

If I went DIY 2 way how would the motors work? Is there one motor at each end of the top of the mask that allows vertical lift and drop of mask frame? How are the 2 presets controlled? My screen will be 72.6H X 124.6W.

Thanks,
Dave
 

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Discussion Starter · #16 ·
I would love to get in on the 30% discount but I am still clueless about exactly how to build the masking system despite looking at your parts list.

If I went DIY 2 way how would the motors work? Is there one motor at each end of the top of the mask that allows vertical lift and drop of mask frame? How are the 2 presets controlled? My screen will be 72.6H X 124.6W.
Dave, my thread is not yet a complete how-to yet since the build is not yet completed (working on the ceiling/soffits). For each of the 4 masks (each of which rolls up on a single roller tube) there is a single Somfy motor (at one end of tube) that can drop/lift the mask (the other end of the tube spins freely). The Somfy motors have encoders/etc built in so that you can program 5+ preset drop distances.
 

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Dave, my thread is not yet a complete how-to yet since the build is not yet completed (working on the ceiling/soffits). For each of the 4 masks (each of which rolls up on a single roller tube) there is a single Somfy motor (at one end of tube) that can drop/lift the mask (the other end of the tube spins freely). The Somfy motors have encoders/etc built in so that you can program 5+ preset drop distances.
How is the project going? I'm about to attempt something similar to Youthman's build. I plan on having an AT screen that I can swing up to access speakers and equipment. I need a 4 way blocking system for a 150" screen that I can size down to 135" or scope. How rigid is the aluminum frame?
 

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Discussion Starter · #18 ·
How is the project going? I'm about to attempt something similar to Youthman's build. I plan on having an AT screen that I can swing up to access speakers and equipment. I need a 4 way blocking system for a 150" screen that I can size down to 135" or scope. How rigid is the aluminum frame?
I'm embarrassed to say I've actually taken a step backwards and ripped out the drywall in my room two months ago to do a full soundproofing as part of the (forever) remodel. I've been without for almost 15 months but I've stepped up my game to get it done...

The 40mm profiles (still sitting in their packaging in the garage) I'm using for the independent screen frame are beefy, I wouldn't be concerned with putting it on a gas spring on each side so that the screen frame could be lifted 90 degrees. Let me know how that goes as I may want to steal some ideas on this since I'm now building a baffle wall that I may want easy access to.
 

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I'm embarrassed to say I've actually taken a step backwards and ripped out the drywall in my room two months ago to do a full soundproofing as part of the (forever) remodel. I've been without for almost 15 months but I've stepped up my game to get it done...

The 40mm profiles (still sitting in their packaging in the garage) I'm using for the independent screen frame are beefy, I wouldn't be concerned with putting it on a gas spring on each side so that the screen frame could be lifted 90 degrees. Let me know how that goes as I may want to steal some ideas on this since I'm now building a baffle wall that I may want easy access to.
My main concern is rigidity so that the screen material is not affected with the swinging of the screen. This means the frame must be quite rigid and thus welded together, which then removes most of the benefits of the T bars. I'm working with an engineer, 2 fabricators and anyone else with any useful knowledge I can get a hold of. The full plan is to have a 150" 16:9 swinging screen with auto masking and if possible add an LED strip for ALR. It's a tall order. When I figure it all out, I'll share the details and pics with you.
 
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