Screen thoughts?

[jskibo]

So I was roaming the home improvement store at lunch, looking at costs for my wood platform and such.....

I was trying to get a handle on my screen build as well;

First thought was wood frame, find someway to draw and cut my arcs out of Plywood to attach the 2x4 uprights to and then use that glossy 1/8th" white panelboard for at leat a temp screen.  The make a plastic end channel for it I thought I could screw to the 2x4's and slide the panels in.  I think it would work, but its big, bulky, heavy and permanent.

I happened down the plumbing aisle and got to looking at the schedule 40 3/4 or 1/2" pipe.  Its very flexible, comes in 10ft sections, lots of connectors....

Got me thinking.  Why not build my arc screen out of that?  I could build the whole skeleton rather cheap.  Drill the connectors at key points to slip bolts through so I can take it down.  Then use a screen from this guy  http://stores.ebay.com/Carls-Place-Projector-Screens?_trksid=p4340.l2563 and bungee it to the frame?
I might have to reinforce it in a few more places with uprights depending on the weight the screen puts on it but that should be easy.  I think I would need to extend it past the base to tie it back together in order to maintain the pressure needed for the front arc, but at $3 for 10ft of pipe and a few $0.33 connectors, it seems rather cheap, even with $200 for the screen.

Any thoughts?  Anyone do this?

[jackpilot]

Not at that stage yet but I used a one projector setup with  a 4X8X¼ Corroplast white board and the image was fine.
That material (like corrugated cardboard but plastic) sells for cheap per sheet, weighs nothing and is super easy to bend.
Not a permanent solution but can help you define a lot of parameters before building a monster stucture.
http://www.coroplast.com/

I also built a skeleton cockpit shell with ABS plumbing years ago....was small sections but highly shaky and "bendy"
Jack

[Flying_Fox]

Hi Jack,

I tried coroplast  for screen, however I found that the thin corrugated lines are still slighty visible on surface.  Also I thought that it would be  harder to manage the seams in more flexible sheets - that's why I went with 5 mm  4' x 8' hardboard panels.

Nick

[Flying_Fox]

Hi John,

Looks like your 12 x 22' bay with 12 ft ceilings would fit only ~ 200 cm screen radius, which you would need to turn at ~45 degrees to the wall inside the bay. This practically matches my screen layout that I described here:  http://www.cockpitbuilders.com/community/index.php?topic=1821.msg17641#msg17641

I have 370 cm room width - slightly wider that your 12 ft. With ~200 cm average radius you can count on 700 cm screen arc at ~ 200 degrees - GT720 will not cover more.

With your dimensions it's probably harder to fit the structure with tension cords and fabric screen, because the support structure in that case (like from ABS pipes) probably would be thicker. You might need some extra space to adjust the tension
In this case you would need to put it along the longer wall.


Since you have the same Optoma GT720 projectors as me, you will have the same problem with image distortions as myself. The screen will not be completely cylindrical - my screen radius in the centre is 195 cm, 220 cm on the left and 215 cm on the right. This is measured from the point where I initially placed the center of the screen, however the central projector lens is 15 cm behind that spot, while the centers of other projector lens are where their cases allowed them to be

The height of screen bottom from the floor is 72 cm, screen top is at 195 cm. (40 cm from the ceiling, which is at 235 cm).

You can place the projectors on the box on the floor. and adjust to the desired height. and see what it looks like. I would highly recommend to build the screen and projection system first, before the sim base and MIP are installed.

Your ceiling is high and you will need some extension pipe and wooden structure to arrange the projectors. So, it's much easier to do it all on the floor first.

In any case you would need the projector mounts with adjustable heads.

Nick

[jackpilot]

Hi Jack,

I tried coroplast  for screen, however I found that the thin corrugated lines are still slighty visible on surface.  Also I thought that it would be  harder to manage the seams in more flexible sheets - that's why I went with 5 mm  4' x 8' hardboard panels.

Nick

Agreed , I was just suggesting as a temporary set up to help  figure out things.
JP