Landing Gear and Bevington Object shadow study

[Greg Daspit]

What are the approximate diameters of the wheel and tire?

Thanks,

Jon

The undeformed tire diameter is 35".  The wheel hub is 6".
The tire in the Bevington photo is sort of "G" shaped instead of "O" shaped so it does not have a consistent diameter.

[Randy Conrad]

Good Evening Guys!!! I was reading Greg's post just now and remembered something that was presented several years ago on the forum. Is it possible Ric, that the Bevington photo of the landing gear became part of the G feature you guys found? Also, I saw the new photo layout for Tighar...nicely done. With that said...if the rocks laying on the beach like your picture shows...and Amelia did land...what scenario would we have if she was to dodge a whole set of rocks coming right at her? She would have braked super hard and would have had to go left or right...and thus causing a chain of events to happen! Something to think about!           

https://tighar.org/wiki/G_feature

[Greg Daspit]

Good Evening Guys!!! I was reading Greg's post just now and remembered something that was presented several years ago on the forum. Is it possible Ric, that the Bevington photo of the landing gear became part of the G feature you guys found? Also, I saw the new photo layout for Tighar...nicely done. With that said...if the rocks laying on the beach like your picture shows...and Amelia did land...what scenario would we have if she was to dodge a whole set of rocks coming right at her? She would have braked super hard and would have had to go left or right...and thus causing a chain of events to happen! Something to think about!           

https://tighar.org/wiki/G_feature

"G" shaped is just my description of the estimated tires shape. My estimation is it is similar to the shape of the tire after the Luke field accident based on where the shadows fall, and could not fall if fully inflated. The "G feature" is just off the lagoon on the other side of the island and not near the reef where the Bevington photo is.  Interesting how close the "G feature" is to the Bushnell survey points.

[Greg Daspit]

Here are two experiments proposed to further test the Bevington Photo:

1.   The full size mock-up experiment. It would just include the worm gear and the fork with wheel hub without tire.  The goal is to test the angles and size of the hard parts by doing an overlay using a real photo of the mock up to compare with the Bevington photo. The photos would be taken from the same distance so the perspective is the same. The material used in the mock-up will be better if it was lighter. This is because you will need to adjust and support them in different positions. This could take multiple attempts. If the mock-up is heavy like the real thing, then support structures become a bigger issue. I'm thinking a lightweight box frame with fishing line to support the fork below it. The worm gear can have a simple brace mounted to the unseen side. ¾" plywood painted a reflective color can be used for the worm gear. PVC pipe may work for the fork.  I don't think it is realistic to do a shadow test with tire and fender full size. This is why the virtual AuoCAD experiment was done.

2.   The small scale mock-up experiment. Goal is to test shadows of the tire and fender by using a small amount of clay that can be deformed.  It can be worked on inside with artificial light source so becomes realistic.  Something like clay or Super Sculpey can be used to work on the fender and tire. Polystyrene pipe shapes and sheet from a hobby or model railroad shop can be used for the hard parts. Once done, a real photo could be taken from a scaled distance and an overlay test done. Not sure how scaled distance affects the perspective?

The tire would not be something that needs to be 3D printed in any of the two experiments since its shape would have to be estimated by trial and error in a material that can be deformed. The Autocad experiment shows the tire had to be deformed.
I'm willing to work on the small scale model experiment and even build it from scratch.   I can assist with dimensioned drawings if someone want to take on either building a full size mock up or a small scale mock up.

[Ric Gillespie]

Has anyone attempted to perform any analysis of the image portion that is in the water below the object?  Was a decision made that said analysis was of no use?

We can't analyze what we can't see.

[Greg Daspit]

Ric,
Has anyone attempted to perform any analysis of the image portion that is in the water below the object?  Was a decision made that said analysis was of no use?

thnks
Leon

If by "below the object" you mean light colored areas on the lower part of the image, some analysis was done but it was not intentional. When assigning the surface material as water in Autocad the light area in the rendered image "below" what would be the fender consistently showed up as a wave distorted reflection of the fender.

  The light areas to the lower right of object could be splashes or other objects but there is not enough there to do an analysis of. By that I mean there is no combination of light areas and dark areas that you could compare to something. It's mostly light areas and no discernible dark areas. My guess is it's a piece of reflective material so low in the water it doesn't cast a discernible shadow or it's a splash of water.