Building an Aerodynamic trailer for VW Jetta

[bentring]

JulianEdgar I knew the hard edge wasn't ideal and someone would call me out on it pretty quickly. My immediate goal was to make the trailer usable and adaptable over time. Unfortunately, aerodynamics take a lower spot on the requirement list for this project than utility and cost, but I did want to keep it as good as I could with my skills and available tools. I will probably test a few methods of rounding the edge later, but for now the existing basic shape is set in stone, err metal.

I considered attempting an Airstream type curved front but decided my metal skills weren't quite up to that, especially with limited materials. I've considered just making a curved plate to round the front corners over the existing hard edges from scrap pieces. I would like to build a bulkhead for extra storage similar to a tongue toolbox that could go to about where the gloves are that curves to the outside edges.

The trailer's only purpose has been to keep me having to own a truck for construction and taking off trash. I've been dragging the thing around for years with scaffolds just strapped to the aluminum plate that is now the main side walls.

I've seen that polymetal many times before from you freebeard. How well do you think it would hold up to abuse?

[freebeard]

Those test scraps have been long since recycled. I don't have a camera with a good battery to make a new one anyway.

The finish is enamel on aluminum on the plastic substrate. It's reported to be as stiff as 5/8" plywood. I doubt I could dent it with a hammer.

The edge detail would work as well in sheet metal. A good next experiment would be to make a curved rather than straight edge. That would require an edge/bead roller rather than the straight roller I used.

[JulianEdgar]

Originally Posted by freebeard

I suggest roll the edge to 45° and then add a 90° flange. It leaves a seam in the middle of a 90° edge. (The sample was Polymetal so it burst the outside of the bend)

Yes that is a good approach.

[freebeard]

If you bead-roll a curve, I could retire that old pic.

Might need to shrink the 90° flange.


youtu.be: Home Made Sheet Metal Shrinking Tool

[bentring]

Uhh, that might be ever so slightly out of my limited abilities to create. I got a hammer, I was thinking something more like this as a temporary fix.

https://www.youtube.com/watch?v=mSAkS352gw4

[freebeard]

JulianEdgar is the guy with the bead-roller. That was directed to him.

In the video the [nylon] hammer to upset the metal is trivial compared with the planishing hammer.

Simple curves are... simpler. For a compound curve shape, flat sheets with curved edges and curved ribbons for the corners could be finessed together. I think the long ribbons would taper at the ends. Maybe contrarywise. They could be rectangular strips with rivet holes in curves.

The advantage of a material like Polymetal is it's pre-finished. For the final iteration, maybe Polymetal flats and aluminum flashing rolled for the edges?

[bentring]

Well ultimately what I'm making is a modified teardrop style enclosure with a lifting rear lid. I've been researching, brainstorming and mentally building since I got the thing. Being a construction trailer, I don't mind if it looks a bit rough so I can later test just about anything with flash metal and screws.

I didn't find many DIY teardrops I'm capable of making that have a modified front. Learning how to do fiberglass would be the ideal method if not for it getting ruined, and I've been putting off the project mainly because I didn't want to use traditional plywood with skin. I never even bothered to check the price on the polymetal long ago because I assumed it would be cost prohibitive. If I wasn't given the stainless I probably would just have simple stow away side rails with a tarp to be honest.

The only thing I could imagine myself building is similar to what you describe, and I could work it out in a later stage. A bulkhead with strips similar to how an airstream is constructed which I could double as storage. The hard edges will be getting a trim of some sort, and I've wondered if I could make it rounded and rather oversized...

[freebeard]

People may groan that I'm re-using this again, but....



Don't recall where i snagged these from. I like the '59 Cadillac tail lights.



A good strategy might be a flat sided teardrop with pontoon fenders.

Have you looked at foamies? Teardrops n Tiny Travel Trailers Board index ‹ Tiny Travel Trailer Designs ‹ Foamies

[bentring]

Yes, I came across that site a while back on an image searching rabbit hole that led me to a picture in this thread (don't click it JulianEdgar ). There's also a smoke test video on the last post of that thread that's neat.

I'm a heavy lurker so I've seen those sketches before, and I liked the style too. I've toyed with similar thoughts and all kinds of copycat stuff really, up to crazy shapes that would envelop the tires completely. Once I get the basic shape completed, as my time and interests are permitted I can temporarily play with many ways to block the wind.

[bentring]

Before it slips my mind, I also remember seeing a post, blog or video some time ago where someone used some sort of fabric attached to the rear of the vehicle and front of the trailer on a long trip of some sort. Ring any bells?