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Old 03-31-2019, 11:07 AM   #7 (permalink)
kach22i
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Quote:
Originally Posted by aerohead View Post
For crosswind stability (anti-roll moment) softening the upper edges the whole length of the trailer will help,as well as reduce drag as you see in the schematic of the bus.(hash marks)
Leading edge softening is a must except for the bottom,which should be flush with the tow vehicle,unless you wanted to treat the trailer bottom as an up-swept diffuser.
The rear vertical edges can be sharp,to maintain a controlled separation line.
All good stuff.

This thread inspired me to do a little doodling last night, as I was not sure where my old sketches left off, so I drew a somewhat rectangular in section box with rounded top edges.

The profile side view was truncated tail aero-template.

The nose was rather bulbous, neither blunt nor pointed.

To have a an actual useful interior that one can stand up in, it is a single hinged at front lift at back roof with tent-like triangle sides in the erect position. The walls are about a foot thick with built-in's, 12" radius at top/roof. 8-foot wide trailer minus 12" and 12" leaves 6-foot wide of maneuverable waking surface and ceiling surface.

There is no taper to the sides, the sharp rear edges have a little cavity box effect to them to act as a water drip edge.

Maybe I'll post something after Monday, but I don't want to hijack this thread. I want stcyrwm to start posting some of his sketches.

In my opinion, unless the wood construction is honeycomb Bass/Balsa epoxy and fiberglass cloth coated, it's going to be much heavier than composite foam and fiberglass or aluminum construction.

If you build this like a house, it's going to weigh as much as a house.

Do you really want to be towing a house around?

Personally I'd look to hovercraft (UH Hovercraft thin plywood on foam epoxied sealed) and aircraft construction (spruce spars and skin?) for a project like this if wishing to involve wood, and I'm an architect.

Aerohead has posted the fuel savings for aerodynamics, maybe he will be so kind enough to post something on weight savings and fuel.

The nice thing about using foam or honeycomb in the design is the insulation properties.

Perhaps thinking about this as an upside down boat would help.

If you build using a stress-skin construction method, the heavy wood framing and form rigging can be removed.

Plane

Boat

House


Your three basic constriction types above, with hovercraft and perhaps trailers being in between planes and boats cost to weight wise. There are so many different ways of building cars that I don't want to get into it, besides towing a car behind you is far more a weighty proposition than a trailer, boat or hovercraft.

In general, the lighter you make it, the more expensive at the same strength.

The heavier, the cheaper but not cheaper in gas.

Gotta find that happy compromise, and one that works within your skill and budget.

This is all part of design, and not an after affect or by-product.

EDIT:
Photo of a UH (Universal Hovercraft) build.

http://imgurl.info/explore/uh-hovercraft-build/


Not recommending the above, just providing food for thought and because others may not be familiar with this home-build method.

Just start with looking at how other camper trailers are built for starters before trying to reinvent the wheel.

EDIT-2:

Using the image search terms "camper trailer construction" provides a wealth of construction types.
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Last edited by kach22i; 03-31-2019 at 12:30 PM..
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