Goldfish Mirror - Side Mirrors

[kach22i]

Originally Posted by cfg83

snowmobile mirrors :

CarloSW2

Very handsome, and sporty looking.

[kach22i]

Based on that NASA CD Shapes illustration, I think it/they would say the half-sphere is more aerodynamic than the lower rectangular one. Somehow my intuition says otherwise.



What do you all think?

[Vekke]

I would say the the half sphere on just basic shape, but depending how and where you would install the mirror the lower version can be as good. For user friendliness IMO round mirror is much easier to use. On narrow and wide view it is diffult to process the data you see on your head.

[Patrick]

Originally Posted by kach22i

Based on that NASA CD Shapes illustration, I think it/they would say the half-sphere is more aerodynamic than the lower rectangular one. Somehow my intuition says otherwise.



What do you all think?

I think the half-sphere will have less drag due to skin friction. The rectangular mirror has about 7 times the surface area.

Round: area = 4PiRR/2 = 4(3.14)2(2)/2 = 12.56 sq in.

Rectangular: area (appx) = 5.5(2)8.375 = 92.125 sq in.

92.125/12.56 = 7.33

So unless you use a laminar-flow shape, I think the rectangular will be worse. But the laminars have their own set of problems - surface smoothness and cleanliness are paramount. Hard to maintain on a car.

[jime57]

Originally Posted by Vekke

I would say the the half sphere on just basic shape, but depending how and where you would install the mirror the lower version can be as good. For user friendliness IMO round mirror is much easier to use. On narrow and wide view it is diffult to process the data you see on your head.

I think that there is lots of truth in this statement. The way the brain processes the data is very important.

But there are other factors related to the geometry of mirror size and placement which have a strong impact on mirror effectiveness. I tried masking off much of my insight mirror to simulate a small 2x4.6 inch racing mirror. Through the experiment, I began to understand some of the size and geometry constaints. In order to have depth perception, both eyes must see the target simultaneously. Since the eyes are separated by 2.5-3 inches, this factor alone limits the smaller practical limit of mirror size. But that isn't the whole story with effective depth perception. The distance(i.e. placement) of the mirror from the eyeballs also has a complex effect on how depth perception works.

All in all, I found that 2x4.6 inches seems too small for any practical location on the Insight 1. Your results may vary. The experiment is pretty easy to do, all you need is some duct tape or masking tape.

[cfg83]

kach22i -

Originally Posted by kach22i

CarloSW, that is what we call "out of the box".

Thanks, my methodology is to adapt "ready made" parts wherever possible. I'll spend a year looking for an off-the-shelf part. It's like a treasure hunt.

CarloSW2

[dkruitz]

Some hot rods mount the mirrors at the top of the door frame - this is much closer to the eyes and you might be able to get by with a smaller mirror in that case.

Here's an example link: CAR FEATURE>> FJ45 LAND CRUISER LOWBOY HOT ROD - Speedhunters

Now in this case the front of the door is fairly vertical and the mirror isn't much closer to where it would be if it was mounted below the window, but on cars with a substantial windshield rake, you might be able to get it a fair bit closer than it's stock location.

Taken to the extreme, I recall mirrors for cyclists that mounted on the helmets - they were almost postage stamp sized, but because they were so close to the eyes they gave a large field of vision.

[cfg83]

kach22i -

Originally Posted by kach22i

Very handsome, and sporty looking.

Yes, they remind me of a small "baby turbo" mirror :



One classic mirror you may like is the $ebring mirror :

https://www.pegasusautoracing.com/pr...asp?RecID=1554


CarloSW2

[Vekke]

Diameter of my mirrors is 3 inch. I would not even think putting that small mirrors to my car unless they are convex. With those there is about 2.5-3 meter blind spot behind b-pillar but bacause most cars are over 3 meters there isnt any in motorway speeds. Manufacturing costs for one mirror will be about 25€.
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Why the images dont show in my posts if I try to put them without the link? I have had this problem since I joined :/. Press quote and tell me. In my opinion I have done it right?

[BamZipPow]