Display Screen: Overkill.

[geneb]

After getting my three projectors built, I needed to build a screen, right?

Guess what happens when you screw up your calculations?

You get this:

http://www.simpits.org/geneb/wp-content/uploads/2010/06/six-segments-3.jpg

There are six segments to that screen which is 22.5 degrees short of 180. I didn't assemble the last two segments. The diameter of the screen is right around 24 feet.

Canvas makes a great screen material. :)

http://www.simpits.org/geneb/wp-content/uploads/2010/06/video-test.jpg

It turns out that the actual diameter for the screen should have been between 15 and 17 feet. Nothing like being off by nearly 9 feet, eh? *laughs* Fortunately, OSB is still pretty cheap and it makes a great building material as long as you understand its limitations.

The above picture also shows the three projectors I built. Each one will get its own tower to hold it in place. With any luck I'll get both the new screen parts and the towers done this coming weekend.

g.

[ANDYSMITH]

"projectors you built"?? please elaborate.

Andy Smith

[Sean Nixon]

"projectors you built"?? please elaborate.

Andy Smith

You read that correctly, projectors he built. I've seen the video!

[geneb]

Andy: I built three 1024x768 short throw projectors for a bit less than the cost of buying one.

I got the optics & light parts from http://www.diyprojectorkits.com.

Each projector is 30" long by 17" wide. They use 400W Metal-Halide bulbs with a color temp of 6500K. The bulbs are good for about 10k hours each and if memory serves, are less than $50 to replace.

If you head over to http://www.youtube.com/f15sim, you can watch a kind of walk-thru video I did on the projectors.

Sean: \o/ :)

g.

[Sean Nixon]

So how come your calcs were so far adrift?

[geneb]

Pick any two:

1) I suck at math

2) I _really_ suck at Geometry

3) I have no idea

:)

g.

[Sean Nixon]

LOL! I suppose it's difficult when you build your own projectors and have no figures for it.

You know about the screen size calculator at projector central don't you?

http://www.projectorcentral.com/projection-calculator.cfm

[geneb]

I didn't see "Gene" on the Brand dropdown. :)

The focal length for the projector is about 120" and that gives me a screen width of right around 110". The major issue with my original design is that I was trying to keep the projectors from interfering with one another - location is pretty important when the projectors are huge.

The new screen will cover 225 degrees of arc (75 degree FOV per projector) and with any luck I'll get it right the 2nd time. :) I'm using NThusim Pro to do my pre-warp.

The only down side is that it'll be tricky when trying to set up the same screen system for the F-15C, which is a LOT bigger than my little 109F/X.

g.

[ANDYSMITH]

I am speechless...you are my new hero!!!

Andy

[geneb]

Hehehe. Just let me know who the old hero was so I can run when I see him coming. :D

Seriously though, there's no rocket science going on - just building on what others have done before me.

What kind of 'pit are you working on?

g.

[ANDYSMITH]

Hi, full size 737ng with as many projectors as i can afford...I have two and am saving for number three and a TH2GO but I LOVE to build new things that I know nothing about so I am going to research this. And if it is in my realm to do then I will do three the same like you. Right now I use one in the living room and one in the sim room. They are NOT short throw so I have to run the sim reflecting off a mirror. So building three short throws would be the way to go.

I am still in shock that this is even possible.

Andy Smith

[geneb]

Andy, you're welcome to stop by on a Saturday if you want to check out how I did it - you're only 40 miles or so north of me.

g.

[wledzian]

Gene,
I'm also only a few miles north of you, in Auburn - directly under the downwind leg to Auburn airport. Any chance I could stop by as well?

[geneb]

Sure, no problem. I'll PM you my Cell#

g.

[737NUT]

I went to the DIY projector site, LCD, 395.00 Starter kit 550.00, Box 99.00 I don't see where it's cheaper than buying one, or am i missing something?? I can get new very good projectors for under 700.00 all day long. Don't get me wrong, i love to build stuff myself but i don't see a cost savings.

[geneb]

I bought three of the S-15 starter kits for $875. Three 1024x768 LCD panels from eBay for $50 each. I built the enclosures myself. Not including the case material, each projector ran about $341 each.

If memory serves, the LCD panel he's offering is a 1900x1200 panel. I'd LOVE to see the machine required to drive three of those simultaneously through a TripleHead2Go. :D

g.

[ANDYSMITH]

Hi, I would like to stop by and see inside these projectors.. I put Seattle in there because of the world wide members, I live in South Prarie..not far at all.

Andy

[Nick1150]

WOW that is a great project :D

I was thinking to do the same thing with dexion metal columns, and in fact I have designed in paper something similar :p

[geneb]

Hi, I would like to stop by and see inside these projectors.. I put Seattle in there because of the world wide members, I live in South Prarie..not far at all.

Andy

No problem Andy. Just PM me and I'll give you my cell #.

g.

[geneb]

WOW that is a great project :D

I was thinking to do the same thing with dexion metal columns, and in fact I have designed in paper something similar :p

Dexion metal columns? What are those?

The new screen layout is going to look like this:

http://www.geneb.org/pitkit/screen/gene225.pdf

A good friend of mine put that together for me. He's forgotten more about AutoCAD than most people know, so he's a handy friend to have. :D

I'm going to use un-docked windows set to a 75 degree FOV to pull off a 225 degree display. The center point of the circle in the PDF is the theoretical eye point, but it may actually be a bit ahead of that.

For the F-15 I will use the same layout, but built to support a rear-projection setup instead of a front projection setup that the 109F/X will use.

g.