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4-Way Acoustically Transparent Masking - Page 21

post #601 of 835
I also thought of using 4 motors. Makes it a bit more complicated, since there are more position feedbacks to process. I also thought of using light sensors that move with the masks, and stop the masks at the grey bars. BUT in real life I don`t feel the need for something fancy. A few presets and a jog function is what I need. it`s important that repeatability is good. I don`t want to calibrate the system all the time.

The PICAXE28X1 has 256 byte of EEPROM. So with two 16bit counters it can store 64 presets. A few bytes is needed to store counter states, PWM duty cycle osv.. but still room for a lot of presets. I have 12 in my current controller, and I don`t need more.

Gunnar
post #602 of 835
GetGray,

Any luck in speaking with the ESI folks? I'm tempted just to order a unit to play around with.

Ben
post #603 of 835
GetGrey,

Any luck with the ESI people?

Ben
post #604 of 835
Sorry, been swamped. Yes, I had a long talk with them earlier this week. They do not deal direct however as I am a manufacturer and have account with some other companies in their field I believe I can get setup with them. Worthingtons will work for you if you have accounts with them. I'm a capitalist , so my interest is the possibility of putting together a "kit" at different levels of completion, for those who don't have the budget for a Cinecurve, or the ready access to the components, but have the DIY skills like many of you here would be interested in. This post may get nuked becasue of that expressed intent, but maybe not since it's just a thought right now.

Some of what I learned was provided confidentially so I 'm not able to share publically. I can say that they use a variety of proprietary methods that are not encoder based to sense the "position" of the thing being controlled. They are manufacturer (OEM) oriented for customization, but an off-the-shelf controller may work fine. One does need hard stops for calibration, I'd probably implement physical and switch based. For accuracy they think it will work, depending on the mechanicals. However I believe a tube motor based design may be the best interface. Tube hardware is an issue there but I plan to look into a design over the summer. Something fairly easy to retrofit to an existing screen. Looks very interesting.
post #605 of 835
Scott...I sent you a PM...
post #606 of 835
Quote:
Originally Posted by GetGray View Post

Sorry, been swamped. Yes, I had a long talk with them earlier this week. They do not deal direct however as I am a manufacturer and have account with some other companies in their field I believe I can get setup with them. Worthingtons will work for you if you have accounts with them. I'm a capitalist , so my interest is the possibility of putting together a "kit" at different levels of completion, for those who don't have the budget for a Cinecurve, or the ready access to the components, but have the DIY skills like many of you here would be interested in. This post may get nuked becasue of that expressed intent, but maybe not since it's just a thought right now.

Some of what I learned was provided confidentially so I 'm not able to share publically. I can say that they use a variety of proprietary methods that are not encoder based to sense the "position" of the thing being controlled. They are manufacturer (OEM) oriented for customization, but an off-the-shelf controller may work fine. One does need hard stops for calibration, I'd probably implement physical and switch based. For accuracy they think it will work, depending on the mechanicals. However I believe a tube motor based design may be the best interface. Tube hardware is an issue there but I plan to look into a design over the summer. Something fairly easy to retrofit to an existing screen. Looks very interesting.

You have got my intrest!
post #607 of 835
I'm finally making progress on my masking system. The side masks are pretty much done. The top/bottom mask rollers are mounted and I'm working on the guides for the masking bars. This part is more complicated trying to figure out how to route the cables and guide brackets without interfering with the side masks.

My plan is to motorize everything. I'll be using the same motors and Eagle Aspen rotators like Scott.

Steve


post #608 of 835
HI Steve,

Thanks for sharing. Do you have any more detailed shots and description of the parts you used to build your masking sytem ? Do you have a build thread ?

Thanks
post #609 of 835
Nothing more yet. I plan on writing something up when I have time. It's very similar to Scott's design. Aluminum rollers with bearings, u-channel guides, aluminum masking bars, cables with turnbuckles, and the same control system. I'm using a Dalite Cinema Contour screen frame.
post #610 of 835
Thanks, Steve.
post #611 of 835
Thread Starter 
Steve,
It looks great! How smoothly does the side masking work now without the motor? Hopefully it moves very easily.

I like the way you have the roller for the bottom horizontal mask. If I were doing it again, that is how I would do it too.

Good luck! Keep us posted.

- Scott
post #612 of 835
Thanks Scott. It's ok but not as smooth as I would like it. Doesn't seem to be a friction problem, the bearings and guides are smooth. I think it's my gorilla tape job for the cable taper changing the spring tension as it's pulled back and forth. I'll post some more pics when I get the horizontal masks up.

Were you able to finish motorizing your horizontal masks?

Steve
post #613 of 835
Here's an update on my masking project. All 4 sides are up now. Ran into a problem with the top roller. It's not completely straight and rolls out of balance. Hopefully I can find a straight piece of tubing to replace it with. Now I'm working on motorizing it.

post #614 of 835
Very nice Steve. Looks really "PRO" !!
post #615 of 835
Thread Starter 
Steve,
Looks great! You may have already said, but what screen material will you be using? Is the frame DIY too? The masking looks top notch professional! Keep us posting on your progress.
- Scott
post #616 of 835
Thanks Guys,

Scott, the screen is a Da-Lite Cinema Contour frame with high power material. Size is 136"x67".

The fabric shown in the pics is just for testing. I'm doing a black velvet border with GOM acoustically transparent cloth like Scott's. My screen isn't acoustically transparent but the center channel is below the screen. I wanted to keep it up as high as possible so I located the bottom mask roller below the speaker. The remainder of the screen wall will also be covered in black GOM.

Hopefully I'll be able to get at least the side masks motorized this weekend.

Steve
post #617 of 835
Didn't make as much progress as I wanted to over the weekend. Too many other distractions. I was able to get the side mask motor mounted and hooked up. Even though the control system is not yet installed I tested the motor out by connecting it straight to the power supply. It has plenty of power to easily move the masks. My only complaint is the motor is a bit noisy, especially when running in reverse.
post #618 of 835
I was able to get my side masks motorized and am working on hooking up the Aspen Eagle remote control system.

Does anyone have any ideas on how to counterweight the top/bottom masks. I tried attaching lead weight to the back side of the cable. It seems to work but is bulky and hangs up on the brackets.

Steve
post #619 of 835
Thread Starter 
Steve,
If I remember right, you have rollers on both the top and the bottom, correct? Are the top and bottom masks connect to each other?
post #620 of 835
Yes, I do have rollers on both the top and bottom. They are not connected to each other. I was planning on mounting the motor about half-way between them and connecting the 2 pulleys to cables cables just like the side masks.
post #621 of 835
Thread Starter 
If you put the motor pulley in the middle and connect the bottom mask to the pulley and connect the top roller to the pulley, I don't think you should need any counter-weights. I think the torque of the motor should hold the masks in place.
post #622 of 835
What about the opposite side that doesn't have a motor?
post #623 of 835
Thought I'd chime in with my CIH masking design. It took me several iterations to arrive at this which is the simplest design I could think of. It's a dual motor Somfy design. The masking will slide along an aluminum or closet track on ball bearings. The tension on the masking is created by a constant force spring of some sort, very similar to a spring balancer. The only thing I don't have figured out is what lb load spring I should get. I can't seem to figure out what load a Somfy Sonesse 50 motor can handle.

What do you guys think overall? Anything I missed?







post #624 of 835
The best performaance form those type springs comes when you place 2 of them back to back. Otherwise they have been problematic to get them to pull smoothly throughout their range. For ones with enough pull and enough travel you'd have to have them made custom I expect and they are not cheap. If you can find a pre-made unit like the one in your phto with the specs needed, I'd go with it if you want to try that design.
post #625 of 835
post #626 of 835
post #627 of 835
Thread Starter 
Quote:
Originally Posted by Steve Smith View Post

What about the opposite side that doesn't have a motor?

I don't think it will be a problem on the the top roller, but you are right, the oposite side of the bottom mask/roller could be an issue. Maybe you could find a spring that would work like what Pocoloco has described.
post #628 of 835
Quote:


or figure 6 here:

Yes, figure 6 is what I was describing. That was from advise from a spring mfgr I got a long time ago. I don't have much personal experience with them in a working design. Any one of them that has a preassembled mount will be best unless you build/design the "holder" for the springs.
post #629 of 835
Made some more progress tonight. Got the control system working for the side masks. Just need to clean up the wiring and mount the boards.


post #630 of 835
Quote:
Originally Posted by GetGray View Post

Yes, figure 6 is what I was describing. That was from advise from a spring mfgr I got a long time ago. I don't have much personal experience with them in a working design. Any one of them that has a preassembled mount will be best unless you build/design the "holder" for the springs.

Thanks for the tip. I have a single spring right now it and seems pretty steady. I'll see how it pans out on the prototype and will try the back to back thing if I need further stabilization.
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