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Topic: Technique to avoid sag on DIY screens
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Joined: May 14, 2017
Posts: 29
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Hello,

I want to create a DIY stand for a 150 inch projector screen with grommets.

I want to achieve a nice smooth, tight stretched final screen like the below:

https://ibb.co/bWMRpp7

I want to avoid the sag etc. like the below:

https://ibb.co/LCw5bN9

Any advice? Use velcro straps to attach the screen to the stand or plastic cable ties?

Also, per the grommets on the left and right vertical poles of the stand, obviously gravity would want the velcro strap to slide downwards and not stay in position. What do you suggest? Use some tape to stick the velcro in position on the pole so it stays in one position?
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Joined: Mar 28, 2005
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The main thing with your second link is that the frame is too small.

You should use bungees, not velcro, as you want the screen to be pulled. That's why the screen frame MUST be larger. You are pulling it out towards the edges of the frame, not trying to pull it around the edges.

The second screen also doesn't appear to have enough anchor points.

You can get bungees and other DiY screen solutions over at Carl's place.

https://www.carlofet.com/shop/black-ball-bungee-six-inch-each

You can get 40 of them for under 20 bucks. So, a solid choice for connecting to your screen.

For the sides, I would likely drill holes in the PVC (if that's what is used) at the exact location they need to be, then run the bungees through them for best results. Or, you can wrap the bungees and just drill a screw/bolt into the PVC/pipe to keep them from slipping down or up incorrectly.

Carl's place also has some DiY instructions for making a screen...
https://www.carlofet.com/resources/
AV Integrated - Theater, whole house audio, and technology consultation during the build and installation process in the Washington, DC metropolitan area.
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Joined: May 14, 2017
Posts: 29
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Many thanks!

Some questions:

1. What is a good distance to keep from the screen to the frame for the entire perimeter?

2. Can drilling split the PVC rendering it unusable or would drilling give a nice smooth hole? I like the bolt and nut idea to keep the vertical tiedowns in place.

3. Can you point me to an equivalent link on amazon or ebay for the bungee cords?

4. What is a recommended [maybe a popular choice] PVC pipe size for 150 inch projector screen frames? 1/2 inch, 3/4 inch, 1 inch?

Lastly, I need your help with a calculation please.

Screen size - 150 inch diagonal (16:9)

Projector model: Optoma HD200X-LV (Full HD 1080p). Projector ceiling mounted at the back of the room.

Calculation: if I want to fill the entire screen space of 150 inch diagonal, what is the MINIMUM distance that I can have between the screen and the projector lens? I am asking this question because the room that I have is a bit small but still large somewhat, and I would like to be able to fill the entire projector screen.
[Edited by fludge2 on Oct 19, 2020 at 8:03 PM]
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Joined: May 14, 2017
Posts: 29
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Hello AV_Integrated,

I have sorted most of the items in my last post, I just need you help with the below calculation please:

Projector model: Optoma HD200X-LV (Full HD 1080p). Projector ceiling mounted at the back of the room.

Calculation: if I want to fill the entire screen space of 150 inch diagonal, what is the MINIMUM distance that I can have between the screen and the projector lens? I am asking this question because the room that I have is a bit small but still large somewhat, and I would like to be able to fill the entire projector screen.

Projector spec sheet below:

https://www.manualslib.com/manual/504831/Optoma-Hd200x-Lv.html