sepp's second aerocap

[bondo]

Sepp,

The flaps look great and very functional too. Nice work!

Bondo

[aerohead]

Originally Posted by sepp

yesterday i prepared everything and got the cap ready so today all i had to do was make the polyester-fiberglass edges, and paint and it would be done!

but that was verry optimistic, i spent this entire hot sunday in a white overall with cap, gloves, goggles and gasmask sanding and grinding the polyester.
though it went better than last time, the result still wasn't perfect and i had to cut out awhole lot of it that was a bit loose or filled with airbubbles.
but this time i bought polyester body filler! small cans to do touch ups on cars, but i ran out of it and it was getting late so it will be for tomorrow if i get the time.



i did drove it to home and back with the cap on and the flaps open, and visibility is great! the flaps are connected to each other, and i installed a windchield wiper mechanism in it, but still need to connect it to the flaps.



stay tuned!

sepp,a thought came to me,and you may have already hit on this.If the louvers are counter-weighted,as one would do on an airplane's flap or elevator,or the main tube of a telescope on a German-equatorial mount,there would be very little stress at the louver's hinge point,and they would require very little torque to articulate.Cap is looking great,look forward to your progress.

[botsapper]

Sepp everything looks good with your aero-cover. Your adjustable louvers/flaps is ingenious. But if the mechanics prove to be problematic, your opening could be replaced with lexan + louvers (aftermarket suppliers). Even better if you decide to glaze (clear lexan) the the rear half of your hatch cover you could put the louvers inside the clear cover for even a clean aero profile.

[botsapper]

Pardons for the rough sketch. Reminds me of my childhood in the 70's, especially the Mustang's OEM louvers. They had the option for interior louvers but the exterior ones were just cool...looked like shark gills...to a kid.

[sepp]

got it painted! well again...



after hours and days of sanding/filling/sanding/... i got tired of it and decided to paint it already, knowing it wouldn't be a ferfect finish. but at least with a glossy black paint i would be able to see the bad spots better so i could fix them. but the result was verry bad, entirely covered with microscopic scratches left by the sanding. so i sanded it all again, taking off lots of the paint, and then filling it up again and sanding with smaller grit paper etc...

now it's painted again, and the result is much better. though it's not yet good enough so i will later paint a second coat.
i didn't have the camera then, so i have no pics of those stages unfortunately.

still need to finish the flap mechanism (thank you for the counter-weight idea!)
im gonna let it bake in the sun for a few days so the paint can dry completely.



also added 2 reverse lights that will be connected to my standard reverse light, but they can be switched off in the cabin.



so the finishing stage with fiberglassing, filling, sanding and painting, wich i thought would take a day, finally took almost a week.

[Concrete]

looks good

[Christ]

Kinda looks like a car I used to have...

[stevet47]

That thing is soo impressive.

[Big Dave]

Excellent work, Sepp.

I think you are very close to the optimal shape. Yeah, a boat-tail or teardrp might have a lower Cd, the vehicle gets too long to be generally practical and a pickup is all about general practicality.

I like the curved shape. From the simulator ,the curved shape and the straight cap seem to have about the same drag characteristics, but the curved shape looks soooooo much more graceful.

[Jetta90GL]

I'm seriously getting aerocap envy. I wanted to make mine out of welded aluminum flat bar. I may just have to skip buying a welder and keep going with the pop rivets.