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updates, updates!



you are a perfectionist, your craftmanship is impeccable. glad to see someone designing a nice vertical masking system.
 

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Discussion Starter #23

Quote:
Originally Posted by Anthony A. /forum/post/19740595


updates, updates!



you are a perfectionist, your craftmanship is impeccable. glad to see someone designing a nice vertical masking system.
Quote:
Originally Posted by Foosinho /forum/post/19742445


Seconded. This is amazing.

Thanks guys. I'll have an update soon, but a Christmas vacation got in the way...
 

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It'll come when it comes. As long as it does come, eventually!



I'm impressed by your fabrication skills. I can't weld worth anything. Still, this is something I think I'd like to try and duplicate when I get to my theater.
 

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Discussion Starter #25

Quote:
Originally Posted by Foosinho /forum/post/19793550


It'll come when it comes. As long as it does come, eventually!



I'm impressed by your fabrication skills. I can't weld worth anything. Still, this is something I think I'd like to try and duplicate when I get to my theater.

You could probably get the frame welded up by your local metal shop. Failing that you could probably bolt it together with some heavy duty angles in the corners. Of course if you don't want a curved screen then bolted extruded aluminum is the way to go.
 

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Wouldn't bolts hold on a curved screen anyway?
 

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Discussion Starter #28
Boy am I slowing down towards the end of this build ... what with getting used to a new job and Christmas vacation I've only managed to push my screen build along a bit, but I thought I'd share the progress. At least I'm at the point where I just got out my wife's sewing machine to make the masking panels (time to learn another skill).


I fitted the aluminum t-track with epoxy glue and small wood screws. I didn't have any problem bending the track to the radius as it was secured in place. The track was routed flush with the wood but since the slider inserts stand proud 1/32" I glued some 1" UHMF tape next to the track. The idea was that this would create a low friction surface on which the masking panels would slide. You can also see that the frame has been covered with black velvet.




One problem I needed to solve was to figure out how the bungy cord springs where going to cross over with minimal friction. The solution was a combination of some guides and a tunnel for one of the runs. The guides are simply some small diameter aluminum pipe with a couple of washers:





The vertical frame members needed to be stiff (because they are only attached at the corners) and needed a surface on which the masking fabric would rub on. Because the masking mechanism is actually built into the frame they also needed to be hollowed out to provide space for the fabric as it rolls on the aluminum tube. The second picture shows a 1/2" rod embedded to provide the correct height for the fabric payout. I actually ended up using some aluminum tube for this function so it could be glued with epoxy. It was as this point that I tweaked the frame to be perfectly straight -- the aluminum rod acting as a stringer.




Now for the final assembly. First the screen material was stretched over the frame with small rubber o-rings. Then the aluminum strips where fastened through the holes punched in the face of the screen fabric. This pulled the screen perfectly curved and created the gap necessary for the masking mechanism. It turned out that my 1/8" gap was just a little overly optimistic. Everything did fit but it was a little tight for comfort so I used up the rest of my UHMF tape and increased the gap to 3/16" -- still not enough to create a shadow.




I also realized I needed to stop to prevent the slides from running off the middle of the channel during assembly.




This is the point where it starts to get hard to take photos because the Fidelio velvet is so black. The next two photos show one end of the screen with the masking roller fitted and the leading edge of the mask attached to the slides (but without the bungy cord tensioned). The frame sides press fit with a combination to two dowels and one dry biscuit joint to ensure accurate location.




The next couple of shots show the all important masking mechanism. Hopefully this is reasonably clear because it's kind of hard to describe.




This final photo clearly shows how the frame rides 3/16" off the fabric. BTW the leading edge of the masks is made from the aluminum extrusion used to hold door brush seals (McMasterCarr part # 8813T13 ) with the last 2" machined/filed flat to fit under the frame.




Hopefully next weekend I can fit the masking fabric...
 

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Moggie your documenting the fabrication of the curved screen with auto masking is amazing. I have been following your HT and the screen build. The only part that I don't see in the photographs or in the detailed explanations that you have been writing is "how the Bungee cord is attached to the Somfy motors to provide the necessary movement of the masking" I will appreciate if you can write about this with few photographs to show it as well.
 

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Discussion Starter #31

Quote:
Originally Posted by artsmart /forum/post/19902600


Moggie your documenting the fabrication of the curved screen with auto masking is amazing. I have been following your HT and the screen build. The only part that I don't see in the photographs or in the detailed explanations that you have been writing is "how the Bungee cord is attached to the Somfy motors to provide the necessary movement of the masking" I will appreciate if you can write about this with few photographs to show it as well.

I'll try and make it clear with the next post but in a nutshell one end of the bungee cord is attached to the black slider that runs in the t-track (the solid leading edge of the mask is also attached to this). The bungee then stretches to the other side of the screen where it is tied off (not shown in any photo so far). Thus the bungee is constantly pulling on the leading edge of the mask trying to pull it out. The somfy motor unwinds the reel of fabric and as it does so the bungee keeps the mask tight. When the motor winds the fabric back it pulls against the bungee.
 

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Moggie: Great progress!! It looks like all you need to do is attach the fabric and program the motors. Did you ever get the software to program the motors? Are you going to need another piece of hardware to program the initial motor direction and endpoints?
 

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Moggie, I kind of understand it from your explanation above and realise that the bungee is not attached to Somfy Motors but it always creates an opposite re-action to the Somfy's action. I look forward to your next post and the photos showing where the bungee is tied off. Your screen and Masking build is very inspirational and practical. Thanks
 

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Discussion Starter #34
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Originally Posted by Mike_2008
Moggie: Great progress!! It looks like all you need to do is attach the fabric and program the motors. Did you ever get the software to program the motors? Are you going to need another piece of hardware to program the initial motor direction and endpoints?
Hi Mike, yes I managed to find and download the software from the Somfy site. I still need to order the device to set the end stops. Right now I'm trying to figure out how to program my wife's sewing machine
 

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Discussion Starter #35
It worked!!! Didn't have time to program the motors or hang the screen, but it worked. I'm so frigging happy
I'll take some video of the mechanism when the screen is on the wall. That is if it still works when vertical





Just in case this inspires anyone else to build one here are the final details.

I added up all the receipts, total cost was $2123. A little over my original estimate but still about 1/8 of the cost of a commercial system.


Here is some detail on the leading edge of the masks. The picture show how the bungee cord was attached to the slider with two grub screws. Note that the lower hole was elongated to prevent binding if the horizontal frame wasn't perfectly parallel. I also drilled a couple of holes in the flat section so I could sew the fabric tight and flat.




The masks were made from GOM FR701 with a 2 1/2" pocket on the leading edge sewed from felido velvet. The holes in the aluminum allowed me to keep the fabric tight at the ends. This isn't a very good picture but it shows the no stretch edging strip made from iron on hemming tape (single sided) on the back side of the panel. This has the added advantage of stopping the GOM from fraying.




Once assembled the masked were fed in from the ends as I tightened the bungee at the opposite end (the bungee simply exits through a hole and is tied off with a knot). I made room for up to 3/16" bungee but in the end the 1/8" stuff seems to provide adequate pull. If it starts to sag over time I'll upgrade it.




Once the fabric was squared up and stuck to the roller with double sided tape the two side pieces were installed.




Hopefully my RS50 will arrive soon so I can show some screen shots... what you to reckon Jason?
 

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Discussion Starter #40
Thanks for the very positive feedback!

Quote:
Originally Posted by mtbdudex /forum/post/19923035


Are you having a Superbowl party next week to show off your set-up?

Superbowl, what's that? Oh yeah, that game of aerial ping-pong....
I'm an ex-pat Brit and more of a Rugby man myself.


Anyway I won't have a projector by then.


Cheers.
 
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