Answer about collimated display systems

[Craftsman]

Hello everbody,
We have found some anwers for the collimated display problem. But we didn't use complex calculations or "simple high school physics".
By following the valuable instructions of "Question about collimated display systems" just used solidworks.
You may find it simple or awkward please let me know what you want to know.

[Craftsman]

mylar mirror:
Arc Length: 1174.61mm
Chord Length: 1160.71mm
Radius: 2200mm
Angle: 30.59deg

[Craftsman]

screen:
Arc Length: 772.89mm
Chord Length: 754.84mm
Radius: 1028.73mm
Angle: 43.05deg

[Craftsman]

mirrorsheeting.com (http://www.mirrorsheeting.com/)

You may find the mylar sheet that link.
We prefered 2 mil x 54'' (mirrored both side).

[Craftsman]

You may find the mylar film sheet:
mirrorsheeting.com (http://www.mirrorsheeting.com/)

[Craftsman]

This guy gives perfect tips about how to use a mylar sheet and diy vacuum mirrors.
GIANT DEATH RAY Daniel's DIY $25 giant parabolic mirror Rojas Vacuum Mylar Hack - YouTube (http://www.youtube.com/watch?v=FyCLOXF1188&feature=share&list=PLBEF40B354EAE928E)

[adighob]

Can you please draw the location, angle, and type of the projector also?

Thanks

[Craftsman]

Can you please draw the location, angle, and type of the projector also?

Thanks

If you check the forum title Collimated Display Discussion (http://www.mycockpit.org/forums/collimated-display-discussions/) you would find plenty of solutions for the question.

We used basic principles which are explaned in previous threads while drawing it.

There is a convex screen, you just need to align the fov of the projector with the screen. You would use any projector.

The pilot reference eye position and the window frame has been derived from B737.

81078108

[adighob]

Thanks very much for that explanation, now it is clear to me

[adighob]

Regarding the collimated display drawing, I noticed that in your elevation view cross section drawing of the collimated display:
The radius of the screen is 1028.73 mm and the radius of the mirror is 2200 mm.
However, is the radius of the screen in plan view also 1028.73 and the radius of the mirror in plan view also 2200 mm ?

Or can can you set these values in plan view as you like, for example:

Can you keep the radius of the mirror 2200 mm in elevation and the radius of the mirror in plan view 1500 mm,
and keep the radius of the screen 1028.73 mm in elevation view and scale the radius of the screen in plan view proportionately to the new mirror radius of 1500mm, keeping the distance between the screen and mirror the same as you have put?

Thanks and Best Regards,

[Craftsman]

Hi adighob
If you asked about the difference 1028.73 - 1029, it was just rounded up in the drawing.



<tbody>

mylar mirror:
screen:


Arc Length:
1174.61mm
772.89mm


Chord Length:
1160.71mm
754.84mm


Radius:
2200mm
1028.73mm


Angle:
30.59deg
43.05deg

</tbody>

The values on the table are all the cross section drawing of the collimated display. There is nothing about the plan view. The numbers on the drawing and on the tables are the same. Sorry about rounding up.

[Craftsman]

Can you keep the radius of the mirror 2200 mm in elevation and the radius of the mirror in plan view 1500 mm,
and keep the radius of the screen 1028.73 mm in elevation view and scale the radius of the screen in plan view proportionately to the new mirror radius of 1500mm, keeping the distance between the screen and mirror the same as you have put?

Thanks and Best Regards,

I couldn't understand exactly what you mean above.

We've developed our work based on B737. First 737-800 cockpit has been scanned using the optic 3D scanner. Then Eye Reference Position was found using digitized (scanned) data of the aircraft. The FOV of pilot was defined and we found the radius of mirror by following the instructions on thread "Question about collimated display systems" #78 by Mike.Powel.

We used solidworks and the radius of screen is a function of the radius of mirror.
My point is that we can't change the number as we like.

[adighob]

I would like to just clarify
In your drawing, I assume it is drawn in the X-Z plane and so:

1-Radius of Mirror is: 2200 mm
2-Radius of Screen is:1028.73

Since you have not drawn a second view in the X-Y plane, my questions are:

1-Is the radius of mirror in X-Z plane = radius of mirror in X-Y plane
2-Is the radius of screen in X-Z plane = radius of screen in X-Y plane

Thanks and Best Regards

[Craftsman]

There is only one plane and one view on the drawing, it's right side view of the cockpit.
In other words, it's the drawing of vertical "field of view-FOV".
The answer is negative for the questions about radius'.
The horizontal FOV depends on your design criteria and the resources you have such as mylar length of yours. Please read the other threads that explain the design of the screen and the mirror.

[OmniAtlas]

This guy gives perfect tips about how to use a mylar sheet and diy vacuum mirrors.
GIANT DEATH RAY Daniel's DIY $25 giant parabolic mirror Rojas Vacuum Mylar Hack - YouTube (http://www.youtube.com/watch?v=FyCLOXF1188&feature=share&list=PLBEF40B354EAE928E)

Anyone tried heat? Making a Hexagonal Mylar Mirror - YouTube (http://www.youtube.com/watch?v=YpdqJDtjwLo)

[geneb]

Very nice mirror. Totally useless for a collimated display. :D

g.