Replacing Class c motorhome body for touring act

[freebeard]

RIP Bucky

I can't speak for everyone, but I'm trying to keep capturedbyrobots focused. Maybe he'll be ready for this in v2.0.

I'd given up on that page; did you notice he hasn't finished the model he started in 1999. The Sketch-up model from 2008 is new, so thanks.

Have you seen Sir Norman Foster's Dymaxion #4?

You might like this:
SIA Flashback – Teardroppers powered by Ford

[capturedbyrobots]

I moved the template back so the camper front is along with the template front.
Seeing as what you posted about long vehicles not benefiting much from longer taper, do you think this less tapered design is decent? Numbers are width so having to taper out from 5 ft to 8 ft wont be great, but I need the room.

[capturedbyrobots]

Those ford teardroppers are very cool. Beautiful designs.

I could use conduit for the frame, and instead of sheet aluminum I could use a light gauge galvanized sheet. The last galvanized sheet metal I dealt with was very light. I wonder what gauge would be sufficiently strong, but not too heavy? My buddy could hook me up with a lot of galvanized...his friend owns an hvac company.

As well, if I used conduit or 2x2s, what would be the best method to fasten the skin to the frame which would not leak? Caulk under every screw? Spot weld? I have used self drilling sheet metal screws with great success before when I attached 1/2 a VW bus to the top of my old van. That was a great project. VW on top of a 1/2 ton van. So fun!

[slowmover]

Btw, does anyone know of a more aerodynamic roof vent? They really help cool off my camper in hot weather.


Aero, schmero . . FANTASTIK FAN has the best reputation for service, and the performance is outstanding. They have a new vent cover which substantially outperforms the usual ones out there (they say). Worth your investigation as anything that reduces HVAC use is to the good.

Outstanding thread!!

.

[capturedbyrobots]

lol, hvac? I've got none. Well, heat yes but no ac. Bare bones. I'll check em out.
I mostly need it to vent well when sleeping or loading as it's a sweaty job, especially in the south.

This was my first and only major modification to a vehicle, back in 1997. it was a triple decker when you lifted the poptop. I miss it a lot, but it was too short to fit my robots.

[freebeard]

...do you think this less tapered design is decent?

It looks good. Did you gain or lose headroom?

The copy of the Template I have has an instruction to scale to height as you have done for the top, and then scale to equal the wheelbase to work out the ground clearance. Does yours have that note?

The "Aero Rules" in post #16 suggest width x 0.45 (96"*.045=4.3") for the radius, and you have to bump out 18". So it sounds like you could bump out 1' and radius the last 6". If you are planning for the section over the cab to be only 5' wide, the radiused edge could roll back to mimic the template bullnose curve. It would look Art Deco. Instead of a circular radius, a parabolic curve would be nice.

The advantage to using galvanized steel is the body won't turn into an electric battery that eats itself (corrosion).

Picture a 2x2 wood frame without it's skin. You'd have to bracket every joint to make it rigid. You can't just nail it. And it would fight your compound curves all the way. Conduit is easily bend and like Bowlus you could weld it all together (assumes you have a welder, of course).

You could drill holes in the sheet, align it over the conduit and spot weld the holes shut, or drill both, dimple the hole in the sheet and use pop rivets. The nicer it looks, the happier you will be.

What did you think of the Superellipse? What did you think of Drop City?

[capturedbyrobots]

Drop city was great, love the alternative building materials. If I only had a buddy with a junkyard! So the super Elipse can be used for the main part of the upper radius and walls, but the bottom will have the long skirts so would I still want to taper it in?

I gained headroom on this design, I like it, but it sure is ugly. Maybe paint will help disguise the ugly.

Btw, the welding idea rules. I weld every day, so it would not be a problem. Just would have to get some tool to chop the ends of the conduit in the C shape to have the 90deg joints fit tight. I hate having to shape tubing for clean joints with my angle grinder. It's a pain.

With my welder, I wouldn't have to even drill a hole. It'll burn right thru the sheet to the conduit. I know galvanized is nasty when you weld, but I'll wear a respirator.

Ok, so conduit and galvanized sheet it is. Done.

Now, since the body will be tacked to the frame, what method of sealing the seams could be used? I'd love to solder it if I could figure out a way to get it to stick. That would be tight as a mofo! Ive only soldered uncoated steel. Guess I could just sand off the coating at the seams before soldering...

Welding the seams would be tough, as it's so easy to burn thru thin sheet.
Ideas?

[capturedbyrobots]

Since I'm going to be painting this, I guess I could just use some sort of hard body filler over the seams, then sand smooth....that would be the cleanest looking after it's done.

[ChazInMT]

Hey Robot Slave, Been looking in on your build and really had nothing to add till today, I have come up with 2 different things, but it looks to me like you have the one idea covered.

1st I was going to say that your V1 drawing was too tapered, it's surprising how little a taper you need to be effective, but by moving the plan taper back on your rig, you fixed it! Good on ya!

Next, I want to suggest looking for a small FanTech fan for a vent fan, they're whisper quiet and very efficient. An FR125 will use only 20 watts of power, you could buy a cheap inverter to power it with 12v and just use 4" ducting to plumb it. It may take a little more ingenuity to figure out how & where to install it, but for about $110, you really have something that Sucks....er, I mean, Blows...uh, well you know what I mean. When I built houses a a few years back, I used these a lot. Insane quality for the price, the impellers look like aircraft parts.

FanTech Supplier Idea

FanTech Site

Look up NACA vents for providing airflow while the rig is moving down the highway, they are a low drag way to move air.

I would avoid putting anything in the slipstream if possible, it will really be counter productive to what you are trying to do here.

Yer #22 post looks like the way to go. My only question would be how you cover the front wheels, but you could save that for last.

[freebeard]

Drop city was great, love the alternative building materials. If I only had a buddy with a junkyard!

Car tops are great because they are already painted and undercoated, but you could do the same with sheet metal. My concern would be that the gauge of ducting metal might not be up to the stresses out on the road. One construction detail Fuller used was to turn 2 non-coplanar triangles into a tetrahedron. This would be a bazillion times stronger than 2 layers flat against each other.

Now, since the body will be tacked to the frame, what method of sealing the seams could be used?

Jeez, I don't know. With flanged triangles you could be spot-welding on the inside every 3/8".

So here's a suggestion for a hybrid construction: Conduit and simple curves combined with geodesics. The edge lengths of the triangles are mathematically calculable, or you could wrap strings around a football to represent the geodesic lines and pick the dimensions off with a tape measure.



I'm going to go off and do something else now. I'll check back later.