Folding Aerocap

[The Armadillo]

Originally Posted by Grant-53

The local upholstery shop might have some tips on fit and material selection. Looks good.

I agree - I might have a professional sew up the next version of the top. I am going to look for someone that creates covertable tops for cars. I want the next version to have a similar fit and finish to a convertible mustang (or similar car). Just using this one as an experiment to iron out the kinks and learn how it will behave.

[The Armadillo]

Originally Posted by freebeard

Sweet.

Haartz cloth? Radiused leading edge?

How about cam-locks or inflated tubes to rigidify the shell. Is it rigid or flexible when not fastened to the bed?

Thanks Freebeard!

I like the idea of cam-locks. I have some familiarity with sail camber inducers which might have an application here... I need to think about it.
The frame is rigid, but the cover is flexible when it is not connected to the bed.

[The Armadillo]

Originally Posted by botsapper

...ten years later. https://ecomodder.com/forum/showthre...html#post87074

Great minds think alike! I really like those renderings, botsapper! I agree with you, that a rigid frame with a soft covering is the way to go... From a cost, weight and functionality standpoint, it just makes sense. I just need to do more testing to figure out if it is more or less aerodynamic than an traditional fiberglass/ wood type aerocap.

[Xist]

Looks great!

[freebeard]

This one looks taut:

Where this one looks much looser.

Is that a real difference or a trick of the light?

The tailgate bulkhead looks to be an opportunity to tension it. Fold into place and then pull back a fraction of an inch on the trailing edge.

What suprised me was that it seemed to "inflate" into a nice rounded shape.

There is a trailing step edge of 2-3" at the cab. It's reaching for the shape it wants to be. Is there room in the folding mechanism for curved front edges? Do you have a picture of the bare frame erected?

[Vman455]

This is freaking cool!

What might be going on is the air under the cap is stagnant, and at ambient pressure or close to it, whereas the air moving over the outside of the cap, even though it's regaining pressure as it moves back, is at lower pressure. High pressure inside/low pressure outside => inflation. That's not necessarily a bad thing; this article-interview with a GM aerodynamic engineer quotes her as saying,

Tonneau covers for the bed help smooth airflow over the truck, and Bloch says soft covers are more beneficial than hard covers because they form to how the air wants to flow.

I think you'll need sensitive measurement to see any difference between this and a hard cover, but if you can manage that the results should be interesting as to which is better. I'm not sure which I'd put my money on.

[gone9]

Id spend a decent amount of money on that if you ever thought about selling a kit someone could assemble (weld/bolt together at home).....

Seriously I would just a thought.

[freebeard]

If you were to sell a kit, the way to promote it would be to post a how-to on Instructables, and offer the kit if they don't want to fabricobble their own.

https://www.instructables.com/workshop/cars/projects/

[botsapper]

Originally Posted by The Armadillo

Thanks! I didn't build windows in this version of my Aerocap, so I can't see what it happening when I drive, but I have observed the Aerocap from a chase car and sure enough the shape does deform. What suprised me was that it seemed to "inflate" into a nice rounded shape. From looking at the tufts, the are seemed to flow smoothly over the inflated shape. Below is a screenshot from a short video i took (I will post the video later if I can figure out how to remove the sound).

Intuitively figured that the downward airflow will lift the fabric, that's why you might need sleeved seams or hoops on your fabric top and they wrap around transverse bars. In my old concept I left the aero-profile side/nerf bars rigid and you could attach cross bars and the fabric top could be zippered into place.
There are tension fabric structures are easy to install and quite hardy.

https://www.youtube.com/watch?v=RuSfJseSoaA

Great shape and keeping close interest on your testing period...

[gone9]

Originally Posted by freebeard

If you were to sell a kit, the way to promote it would be to post a how-to on Instructables, and offer the kit if they don't want to fabricobble their own.

https://www.instructables.com/workshop/cars/projects/

Fair enough, I just wouldn’t mind paying a fair price for a product too. He spent a good amount of time and money and I just wouldn’t mind paying for a portion of the hard work if a kit or plan came available lol. I really like the folding idea for my truck as I use the bed a lot during certain times, then for months at a time I could use the aerocap for trips etc.