Project, the Third - Now contains collabsible boat tails (1971 VW SuperBeetle)

[freebeard]

Originally Posted by euromodder

The lower design is the way to go.

Granted it is the theoretical optimum, how do you put a window in it? I'm leaning more toward something like this:


The full tail casts a *huge* shadow and doesn't take advantage of the pronounced taper in the cabin of the Beetle. So I radically truncate an aeroform that is no higher than the tops of the fenders and go Tropfenwagen style above that.



Here I've added an irregular cone that defines the rear view. It looks like the secondary Lexan screens could be square or have Batman curved front edges. I'm thinking about an H-shaped bracket that the stock bumper and brackets would bolt onto and that would bolt onto the stock body mounting holes. The rear fenders, deck lid and bumper all come off pretty easily. With lightweight construction (e.g., no back bumper), it might weigh less than stock.

slowmover -- Well, having money but no time got me wherever it did...

I think it all comes down to intention. That's the thing that science can't measure. Well, above the quantum level anyway. (How come Creationists never want to talk about the implications of Quantum Theory. Evolution is easier to understand?)

Anyway, crank-fired ignition and EFI is where it's at. The big forums are:
TheSamba.com :: Index
Shoptalkforums.com • Index page

[aerohead]

Originally Posted by freebeard

Granted it is the theoretical optimum, how do you put a window in it? I'm leaning more toward something like this:


The full tail casts a *huge* shadow and doesn't take advantage of the pronounced taper in the cabin of the Beetle. So I radically truncate an aeroform that is no higher than the tops of the fenders and go Tropfenwagen style above that.



Here I've added an irregular cone that defines the rear view. It looks like the secondary Lexan screens could be square or have Batman curved front edges. I'm thinking about an H-shaped bracket that the stock bumper and brackets would bolt onto and that would bolt onto the stock body mounting holes. The rear fenders, deck lid and bumper all come off pretty easily. With lightweight construction (e.g., no back bumper), it might weigh less than stock.

slowmover -- Well, having money but no time got me wherever it did...

I think it all comes down to intention. That's the thing that science can't measure. Well, above the quantum level anyway. (How come Creationists never want to talk about the implications of Quantum Theory. Evolution is easier to understand?)

Anyway, crank-fired ignition and EFI is where it's at. The big forums are:
TheSamba.com :: Index
Shoptalkforums.com • Index page

Busy week,just now catching up.
*'Apron' is the same as 'ducktail' (used in the 1930s),so the body plan-view taper you've depicted looks like a good 'minimum.'
*From the car-blueprints image it looks like the rear fenders are a lot wider than necessary for containing the wheels.
*If you ran the original 155/15 tires (or even narrower,as with Daihatsu's Cd 0.16 UFE-III' 145s) the sheetmetal could be pushed in and flattened,allowing easier boat-tailing and integration into the tail.Like a 1/2 blister canopy over the rear wheels.
*The rear backlight could be handled like a box-cavity for the upper tail structure,allowing a 'tunnel' through which to look.I did this on the CRX.You get good optics,the glass is protected from the weather,and area below its 'floor' can be used for ducting cooling air into the original inlet.
*By keeping the tail with the original body width your side mirrors allow you to look around the back corners to the rear to compensate for blind-spots.
*If you move the fender portion of the tail forward towards the B-pillars and widen them, you could end up with a horrific vision challenge when backing unless the side mirrors are pushed way out.
Just thinking out loud.
Any way you go you'll have some extremely sophisticated coach work ahead of you.You'll also have something which might end up in a museum of modern art.All your renderings are quite attractive!

[freebeard]

Busy week,just now catching up.

I've been waiting impatiently for your input.

*From the car-blueprints image it looks like the rear fenders are a lot wider than necessary for containing the wheels.
*If you ran the original 155/15 tires (or even narrower,as with Daihatsu's Cd 0.16 UFE-III' 145s) the sheetmetal could be pushed in and flattened,allowing easier boat-tailing and integration into the tail.Like a 1/2 blister canopy over the rear wheels.

The next iteration will have the fender aeroforms be half-bodies split vertically, moving the 'stagnation point' of up to around the axle centerline. With geodesic domes, hemispheres are in the minority; most are 3/8 or 5/8 truncation (due to the icosahedral symmetry). The air flow above and below the equator balance each other, but a 5/8ths sphere has less lift than a 3/8ths.

There's a lot of compound curve. I'm thinking about a fabric/fiberglass rod construction, like the BMW Gina.
The bottom rod being longer than the middle ones could fold or rotate up for wheel/tire access. This would be new territory for me fabrication-wise.

*The rear backlight could be handled like a box-cavity for the upper tail structure,allowing a 'tunnel' through which to look.I did this on the CRX.You get good optics,the glass is protected from the weather,and area below its 'floor' can be used for ducting cooling air into the original inlet.

That's plan B. Sail panels like an El Camino or mid-engined supercar.

*By keeping the tail with the original body width your side mirrors allow you to look around the back corners to the rear to compensate for blind-spots.
*If you move the fender portion of the tail forward towards the B-pillars and widen them, you could end up with a horrific vision challenge when backing unless the side mirrors are pushed way out.

Even with the Tropfenwagen conning tower shape, sight-lines are preserved. The outside mirror looks above the fender line.

Any way you go you'll have some extremely sophisticated coach work ahead of you.You'll also have something which might end up in a museum of modern art.All your renderings are quite attractive!

Thanks. *blush* My graphic skills are limited. The blue car is a commercial model. the white aeroforms I made myself; but combining the two into a single object is beyond me at the moment.

The upper tail is within my woodworking experience. It will be a redwood bender board truss, 2 or 3 1/4" laminations thick skinned with aluminum. The compound curve lower part might be redwood, too. I'll have to do some experiments. Think of a redwood strip canoe.

[aerohead]

With woodworking skills you'll be able to pull off pretty much whatever you set your mind to.
I'm in the midst of a cedar-strip (canoe) aeroshell for the Dodge pickup.
The 1941 de Havilland DH.98 Mosquito fuselage was formed by glued plywood laminations compressed into a concrete mold under pressure from an air-inflated rubber bladder.
If you get desparate,galvanized expanded metal lath can be plastered with drywall compound (USG,Sheetrock,MURCO,etc.) to create a fast-build male plug from which to do a plastic-faced plaster splash in which to wet layup a final compound curvature part.
Some of the low-buck lowriders I grew up with were forced to do such things to create their one-off custom rides.
Plastic body putty on lath has also been used to effect.

[freebeard]

I'm in the midst of a cedar-strip (canoe) aeroshell for the Dodge pickup.

Thinking in parallel. Have you seen this?
Howard Hughes did a short run of these simultaneous with the Hercules H-1. I took the picture at the Evergreen Air Museum.

galvanized expanded metal lath can be plastered with drywall...male plug from which to do a plastic-faced plaster splash in which to wet layup a final compound curvature part.

Shades of Ed Roth. What's with the plastic facing? A parting agent?

[aerohead]

Originally Posted by freebeard

Thinking in parallel. Have you seen this?
Howard Hughes did a short run of these simultaneous with the Hercules H-1. I took the picture at the Evergreen Air Museum.



Shades of Ed Roth. What's with the plastic facing? A parting agent?

I've not seen Howard's boat.I like it! It would make a fine truck shell.Thanks!
Ed "Big Daddy"Roth.Now there's a character! He used to attend the Teen Fair in Los Angeles.He had an air-brush booth and would do T-shirts to the customers specifications.Amazing to watch! The Von Dutch of cotton cloth!
And George Barris would do in 3-D what Roth did with ink.I got to go on a field trip to Barris' studio.He used every trick in the book to create his one-off creations.Fun!
------------------------------------------------------------------------
The plastic facing is tooling epoxy which goes on first,over 3-coats of polyvinyl alcohol mold release agent.
As the epoxy begins gelation,plaster-soaked hemp birdnests are added on to create the composite mold.USG has a line of professional molding plasters used for these.They're tough enough for vacuum-bagging and autoclaves.
If the drywall compound plug is destroyed (and probably will be) during separation it's no big deal,since you have the tough female tooling for the actual part making.
If you're careful with the splash you can layup multiple parts.The 1953 Corvette was created this way.
Sand mix concrete,with a rich mixture of Portland cement can also be used for tooling.Hardware cloth,chicken wire,and 10-10 remesh can be embedded within the matrix for reinforcement.And lifting eyes can be incorporated into the design,as these molds are extremely heavy.The concrete can be primed,painted,wet-sanded,and polished to a glass-like finish.
The stingers for 'poco-loco' and 'Viking' were cast in this type of ferro-cement mold.

[freebeard]

I've not seen Howard's boat.I like it! It would make a fine truck shell.Thanks!

I think one would make a great barn find. You know they're out there.


Here's the rest of what I got. I cranked on that second picture as hard as I could with Unsharp Mask and a High-pass Filter, but I couldn't get readable text. It appears the length was 7', beam 42" and depth 17"; with maybe 56lb weight. I would speculate that where the airplane used 7 plys the dinghy used more like 3. The sample case in that last picture (embiggens more) is very interesting. I see hat-sections, z-sections, arbitrary angles and I-beams. I'm using 1/4" redwood instead of veneers because I have a good supply.

I'm going to be one county over from McMinnville, OR on Thursday, but I can't spring for a ticket just to try again. It's sitting there right under the left wing of the 'Spruce' Goose, anybody can walk right up and not touch it.

Ed "Big Daddy"Roth.Now there's a character!...I got to go on a field trip to Barris' studio.He used every trick in the book to create his one-off creations.Fun!

Yup. Last night I was searching through everything in Google Images by Harry Bentley Bradley. There was an interesting guy; he did Detroit, customs and the first run of Hot Wheels. I was hoping to find a series he did on VWs for VW Greats that show some interesting fender vents and hubcaps. I've got the issue somewhere. Find it? My Attention Deficit laughs.

The plastic facing is tooling epoxy which goes on first,over 3-coats of polyvinyl alcohol mold release agent.
As the epoxy begins gelation,plaster-soaked hemp birdnests are added on to create the composite mold.USG has a line of professional molding plasters used for these.They're tough enough for vacuum-bagging and autoclaves.
If the drywall compound plug is destroyed (and probably will be) during separation it's no big deal,since you have the tough female tooling for the actual part making.
If you're careful with the splash you can layup multiple parts.The 1953 Corvette was created this way.

20 year ago I knew an artist named Jesse (as in "Hey, Zeus!) Nazareth. There was a guy with a lot of living-up-to to do. Anyway, he did a lot of works in epoxy, and he loved to smell the fumes. He's gone now—the stuff scares me.

Sand mix concrete,with a rich mixture of Portland cement can also be used for tooling.Hardware cloth,chicken wire,and 10-10 remesh can be embedded within the matrix for reinforcement.And lifting eyes can be incorporated into the design,as these molds are extremely heavy.The concrete can be primed,painted,wet-sanded,and polished to a glass-like finish.

When I was working for an electronics recycling non-profit, I scored a paper shredder the size of a dishwasher. It was maunfactured in West Germany and sold for $3K new. I got it for $25. It has a 16" throat and can take 40 sheets of paper. It idles through corrugated cardboard. I want to use it to make papercrete. Though I was going to start with paving stones, papercrete is lighter in weight and I'll only have to pay for cement.

[aerohead]

*In 1972 I came back to the 'World' on R&R.My dad took to see the Queen Mary.The
Spruce Goose' was hangered right next door but we didn't go.I might have seen the 'boat' had we gone.Funny!
I've been told that the Boeing Museum is a 'must-see.'Perhaps,one day I'll make it out that way,'n take both in.I'd also like to take the NASA Ames Research Center tour at Palo Alto,CA.
*I'll have to watch for Harry Bradley.That's a name I'm not familiar with.Thanks for the heads-up!
*Yes,the epoxy must be respected.Since it doesn't 'stink' like polyester,you can be lulled into thinking that's it's not as hazardous.I have some West System's that I've saved for 'nice' projects.But I've never done epoxy wet layups,only refrigerated pre-preg aircraft cloth.We still ventilated thoughout the bagging and post-cure.
And during trim operations we had a centra- vac system for every powertool operation.Some believe that the dust will be the new asbestos.
* Papercrete sounds like fun.My dad was in the lightweight cellular concrete business.He used DuPont's 'Duponol'(sp?) surfactant which was turned into a high-strength foam which,when injected into a sand mix concrete,could get the density down to as little as 7-lbs/cubic-foot.That,and papercrete would certainly make lighter tooling!

[freebeard]

Quickly:

Harry Bradley, Steve Sanford and Tom Daniels all published speculative designs in the various magazines. There are others I've probably forgotten.

Concrete Canoe Competition

Have a good holiday.

[aerohead]

Thanks for the custom builders.Looks like they spent thousands of hours having a lot of fun.Nice stuff!
Texas Tech was racing concrete canoes in the mid-to-late 70s.It must have been a regional event between more local colleges and universities.
I've ended up living inside a sort of inverted ferro-cement hull.Living in 'Tornado Alley',it helps a little.