Advice on DIY topper angles

I'm planning out a DIY camper shell build modeled after the GFC Topper and need to figure out what angles to use for the walls. I was thinking having an 8° forward lean in the front and 15° forward lean in the back, and lean in 15° for the sides.

Does something like that sound reasonable? Do y'all think it would look good?

 

Might be in here

How to: DIY Wedge Camper | Tacoma World

 

Ripcord uses steeper angles for the space frame IIRC, around 5° forward (both in the front and back) and 12° inwards. I think that makes sense when strength is a priority since it's holding up a fairly heavy RTT permanently. I'm not going to have an RTT so I'm hoping to sacrifice a bit of strength in exchange for aerodynamics and a less boxy appearance.

 

I would think making them the same as the side of the cab. If they stick out past the sides, the possibility of them making some sort of wind noise would be my concern. Use the level app on your phone and see what degree the cab is.

 

I did mine about 13 degrees inward and forward on all sides. matches the truck almost perfectly.

 

Just along this line of thinking as I've been thinking about building something similar for a while now, you can buy the rounded corners like they use on truck boxes in a variety of styles. Some of the flush fitting styles, where the panels are flush with the corner material, might help with aerodynamics and noise. Random example, no affiliations, that I found just doing a quick search to show what I had in mind. I'm thinking something like the first style in the upper left: https://fleetpartsonline.com/aluminum_extrusions_radius.htm

There are various other designs for the corners and edges that might also help with not only the aerodynamics, but also be stronger than some of the bolt together. There are plastic versions as well if you were more concerned with weight than strength but I'd prefer the more durable option if even just for branches off road.

 

Thank you so much for including the above link!
It's a great source of products I didn't know were even available.
I thought I would have to fabricate some of the items while rebuilding my camper...

 

Glad it helps! There are several companies that make similar products; I was thinking about how bad the gas mileage is on these trucks to start with and how much worse it was going to get if I built a box that jutted out past the cab and figured the rounded corners might help some. I know with the price of fuel, truck makers have been trying all manner of things to try to squeak out a bit more mileage and I certainly wouldn't complain, especially when I'm traveling.