Boat tail bottom scrape plate
 

http://i1271.photobucket.com/albums/...boattail18.jpg

I was thinking that since the angle of my boat tail is so high for clearance reasons, I could make a piece of coroplast that hangs down at the desired angle and that is held up by some cable. This way, when it hit the ground it would simply go up and then come back done smoothly. I've attached a photo of what I have in mind.

Not sure if this would help or hurt aero due to the open sides , but I could probably find some sort of flexible membrane to cover this area.

Let me know your thoughts.

That's just what i had suggested to Sven yesterday.
( I suggested the same thing to Basjoos around a year ago.)
Perhaps its not worth the trouble since the sides might create vortices.
I don't know ....experts - what say you on this matter ?

You would want to have it secured with something that would keep it from slamming up and down every time you hit a bump. ( The noise would get annoying )

If you make it out of coroplast, it's not going to slam, so disregard that last post.
It might even be light enough to be aligned perfectly with the airflow angle, since the oncoming air would lift it to the ideal angle .

Go for it !

As far as the membrane, this would be a perfect test of spandex cloth !

I was thinking pond liner would be make a good membrane. it's durable rubber, but thin enough to make it light.

The only thing I would be worried about is cross winds so maybe the maybe instead of hanging it from cables, it could hang from some sort of hinged arm which would add stiffness from side to side. It would have to be spring loaded then, but it would be worth the extra time to not have the thing blow off in the wind.

I might just have to try this myself!

Hinge it at the front and then use a short wire rope to hold the other end. the sides could be made a bit wider then the tail and just slide past the outside (or into a pocket). this would not work for snow but might be a quick test.

Flexible sides could be made of stiff rubber. They could be made to fold in as the bottom folds up.


Whats the ideal angle for the bottom?

I believe 4 degrees is IDEAL, but I'm pretty sure you can get away with 10 degrees as long as it's a smooth transition.

I like your idea to simply has it slip past the sides for now. should be good for short term testing. I'm guessing I'll be starting on mine in 2-3 weeks depending on my my work schedule, so maybe you can get some ideas from mine or vice versa. :thumbup:

An idea i had was to make a boat tail as low as possible and ideal. And hinge the last two feet of it at the bottom, then place an omni-directional shopping cart wheel at the very end. In the 5% of instances where it would scrape, it'd just lift the rear up and then springs inside would tension it back down. Then you could have a 100% boat tail without worrying about the few situations that would be catastrophic.

Second hinge at 50% at the top. This hinge would have latches so you'd pull into a parking spot, then fold the back half of the boat tail over the front half forming a rectangle or square instead of a wedge. You could parrelel park now or just get the boat tail out of traffic.

The ideas that'l never cause i don't know how to build things!