HUD speedo idea
Mr Whippy - 9/1/09 at 09:08 AM
Hi
I’ve noticed that some modern cars now have the speedo projected onto the windscreen like a plane HUD, I was thinking of doing the same but cooler for
the Bluebird cos it would have the rpm and fuel by simply using an Acewell digital speedo. Using a mirror and a vacuum formed compartment recessed
into the top of the dash it would reflect in the glass quite well even in the daytime. I was going to design it in CAD after measuring the dash and
windscreen angles. Anyone done something like this?
just thought my GPS fitted like this with remote buttons would be pretty smart too 
I recon that even with the GPS the unit would be only at most 4x6 inches in size so really would take up little space
[Edited on 9/1/09 by Mr Whippy]
Rescued attachment projected dash.JPG
02GF74 - 9/1/09 at 10:42 AM
oooh, I can just see it now ....
Rescued attachment hud.JPG
AR-CoolC - 9/1/09 at 11:24 AM
What you need to know is though, that the windscreens in cars with HUD are moddified.
The screens are very slightly triangulated by the interlayer i.e. the glass is thicker at the top than at the bottom. This stops you getting a double
reflection on the two layer of glass.
Mr Whippy - 9/1/09 at 11:36 AM
quote:
Originally posted by 02GF74
oooh, I can just see it now ....
LOL 
hope not!
interesting about the glass, I'll have to see by holding up the GPS to the glass, good info though
Humbug - 9/1/09 at 12:16 PM
quote:
Originally posted by 02GF74
oooh, I can just see it now ....
I don't think it would be back to front and upside down.
If you placed it upside down to start with, then two "mirrors" (i.e. 1 mirror plus the screen) would make it appear the right way up and the
right way round
Mr Whippy - 9/1/09 at 12:43 PM
quote:
Originally posted by Humbug
quote:
Originally posted by 02GF74
oooh, I can just see it now ....
I don't think it would be back to front and upside down.
If you placed it upside down to start with, then two "mirrors" (i.e. 1 mirror plus the screen) would make it appear the right way up and the
right way round
yip, that’s how it works. As for the double refection, I think if it is desplayed at eye level then the refection should be mostly behind the main
image so should not be to much off and issue, we'll see
[Edited on 9/1/09 by Mr Whippy]
JC - 9/1/09 at 01:03 PM
Can't say for the car ones, but aircraft HUDs are focussed at infinity, enabling you to look through them at the world outside, not focus on the
HUD itself. Can't remember enough O level physics to work out where your idea would focus! Did however see something similar on a TV programme
which used a laptop with screen reversing software, and used a CD case as a flip up screen!
[Edited on 9/1/09 by JC]
Mr Whippy - 9/1/09 at 01:46 PM
well the focus will be about a foot outside of the windscreen, much the same as a refection of the top of the dash appears in the glass. I think the
production cars type will be the same unless they have some cleaver lenses in there.
AR-CoolC - 9/1/09 at 03:02 PM
quote:
Originally posted by Mr Whippy
well the focus will be about a foot outside of the windscreen, much the same as a refection of the top of the dash appears in the glass. I think the
production cars type will be the same unless they have some cleaver lenses in there.
The one's I've seen in the BMW 5 series have the image focused at the end of the bonnet-ish.
