Edit: I have been informed that there was another Masking system with a similar name, SmX, that was selling screens and is now no longer viable. This project has no relationship to that product.
With that out of the way, here we go.
This is a project born from necessity. As I began looking toward which screen I'd use for my theater, and in particular looking at masking options, it quickly became apparent that in order to get a screen with a motorized mask in the size I want I'd either have to spend tens of thousands of dollars, or work on a DIY solution. The problem is that I really have no interest in putting a lot of effort into a DIY screen. I'm no stranger to building DIY electronics or motor controls, the problem is that there are so many things to spend time tweaking in a theater, so I decided early on that I'd buy a commercial masking system, or have no masking at all.
That resolve wore thin, however, after I began searching for solutions that would fit my screen size. I really wanted an automatic masking solution, but they were expensive in the size I needed. The Seymour Proscenium series looks like a good value, but it just doesn't go large enough. However, as I began to go over installation instructions for various pro screens, and began to see the materials used, I got the spark of an idea that I might be able to purchase all of the components and assemble them, as if I had bought a kit from a retailer. Even assembling a commercial kit is not a small job, but if I can simplify close to that level it would be a huge win.
Thus the SMX screen was born - the "simple masking experience". Simple being a relative term, most of the complexity is offloaded into the planning and searching for the best pricing on parts. Once you have the parts collected, it should be as close as possible to just bolting together the system as a commercial kit would be, avoiding custom fabrication or electronics.
Many people will see places where they can reduce costs with some custom work, or modify the solution to meet their needs, and that's good. We all have different combinations of design goals. For me if it's a choice of adding a small cost or doing something custom, I've opted to spend the money, but you may choose otherwise. I'm attempting to share the "easy path" I found.
ALL STANDARD DISCLAIMERS APPLY: I'm providing this information in good faith, to the best of my ability. Reader accepts the risk of any incomplete or inaccurate information, if you attempt to follow this guide to build your own screen.
Ok, that was a long intro to get to the substance. This design is for a CIH 2.35:1 dual mask, but could be modified to a CIW, or even a four way mask (some bits on that at the end). At a high level, the system consists of:
- An aluminum frame built entirely from T slot extrusions ordered cut to size
- Somfy radio controlled motor rollers w/remote
- Slide mechanism (plastic T slot sliders, aluminum bar, spring/elastic tensioner)
- And of course, screen and masking material. You can buy this from a retailer made to the size of your frame, or further DIY it.
... pretty close to what you'd buy from a screen retailer.
One last note before I go into detail, I fully expect that over time any links I share to products may go defunct. To this end, I am going to describe what the parts are and the purpose, so that hopefully community members can step in and share their sources for parts, help each other out as time goes on.
Getting the Parts
The Frame is what is called an aluminum "T Slot" extrusion. They are aluminum profiles that have channels in them that can be used to mount things. With the right connectors (generally a screw and a “t-nut”), you can hang anything off this channel in many configurations. Or, you can use the channel as a slide rail with the right plastic sliders (or bearings). It’s a very versatile system used to build all sorts of equipment.
There are a few common manufacturers that for the most part have compatible products. The ones I've run across are 8020.net, tnutz.com, and framingtech.com , some have global distributors. You may be able to save a good deal on shipping if you can find a local distributor. Look for "Ultra Light" extrusions if you go outside of the suggestions below.
Here is the parts list, you’ll need to determine the frame member and roller shade sizes per the information farther down the post. I've included the Tnutz part/link and the 8020 part/link. Note that in general Tnutz was priced better, and most of the 8020 stuff could be had cheaper or faster via typing in the 8020 part number into https://hpeco.com
If you stop here, you can make one super nice aluminum fixed frame. The below are additional parts required for motorization. The primary sources are avoutlet.com or floridaautomatedshade.com, from what I could find. There are a lot of ways you can put this stuff together, and all of the parts can be quite confusing. If you just want to buy the stuff and have it work I suggest trying to source all of these AVOutlet items as-is.
- 4 count profile sliders - 8020 brand 6897 (only option I could find for pre-made sliders)
- 2 count Somfy 1001636 Sonesse 40 (ST40) 404S2 RTS 120VAC Shade Motor - AVOutlet or FloridaAS (choose the 2" crown and drive option but nothing else)
- 2 count Rollease RA2 - 1.5" to 2" Tube Adapter - AVOutlet
- 2 count Rollease idler end pin - AVOutlet model SLPE53
- 2 count Rollease SLAMLS40 Skyline to Somfy ST40 Bracket Adapter - AVOutlet
- 2 count Rollease SLB680R Skyline Shade Brackets - AVOutlet
- 2 count Rollease RTEA5T14-7 Roller Shade Tubes w/ Tape - 2" (50mm) - AVOutlet - Note this is a 7 foot roller, please refer to below to determine the length you'll need for your screen size.
- 2 count aluminum bar, cut to vertical height of finished frame (sourced from local hardware store) - sizing can be anywhere from 1.5" wide x 1/8" thick to 2" wide x 1/4" thick
- 8 count #10-32 x 1/2" screw for mounting roller brackets - Tnutz 10-32x1/2'' BHCS or 8020 brand 3050
- 8 count #10-32 SAE washer for mounting roller brackets - Tnutz or 8020 brand
- 8 count #10-32 T-nut for mounting roller brackets - Tnutz ST-015 or 8020 brand 3201
- ~30 ft of 3/16” shock cord - sourced from amazon or hardware store
- 2 count small eyelet
- 8 small project screws, 1/2” or 5/8” long for attaching aluminum bar to sliders
- 4 count mounting nuts for slider stops - Tnutz DS-015 or 8020 brand 3311
- 4 count extra screws for slider stops 5/16-18 x 5/8" - Tnutz 5/16-18x5/8'' BHCS or 8020 brand 3111
Note, I did not include a remote for the shades. If you want a simple remote, try the Somfy 1810633 Telis 4 Pure RTS Remote Control
, however Somfy makes a whole line of integration components for RTS radio controlled motors. You can get smartphone integration, Graphik Eye/Lutron integration, etc. The simple remote will allow you to program three positions, "open", "closed", and "favorite", which I'd name "2.35:1", "4:3", and "16:9" (in between) and I'd suggest it simply to get started and test things.
Frame and tube sizing
You'll want to plan the parts and sizing of the frame in advance and purchase pieces precision cut from the vendor, if possible. I used T slot extrusions that are 1.5" x 1.5" for the vertical pieces, and 1.5" x 3.0" for the horizontal. This provides two slots on the horizontal members, which allows for the plastic sliders that will be responsible for guiding the aluminum bar masks.
Given the frame design I opted for, here are a few common sizes. The formulas are:
1.5” x 3” piece length = (desired width + 3) / 2
1.5” x 1.5” piece length = desired height
Tube length = desired height + 4”
I'm having trouble trying to create tables on the forum, but here are some common part sizes for CIH 2.35:1 screens:
screen size | 1.5” x 3” T slot (4 pieces) | 1.5” x 1.5” T slot (4 pieces) | Aluminum tube (if using same motor parts I did) (2 pieces)
180” wide| 91 1/2” long | 76 1/2” long | 80 1/2”
160” wide| 81 1/2” long | 68” long | 72”
140” wide| 71 1/2” long | 59 1/2” long | 63 1/2”
120” wide| 61 1/2” long | 51” long | 55”
Lastly, before I close off this post, I want to mention that I intend to add instructional in follow up posts. I also want to leave you with some photos and diagrams to provide a better understanding of the finished product.
2 way mask CIH Screen
4 way mask screen
(Not fully detailed in this post, or built to completion in any way, but some proof of concept designs and mockups for people to think on):
Finally, I should give recognition to a few projects that served as inspiration: