plans for a Tinstream?

[Jiminsav]

So, how's gonna be the first to draw up a set of plans to enable me to make one of these out of wood? not the outside, just the frame.

[halfdome, Danny]

If you know the outside dimensions who needs any stinkin' plans . I'd lay it out full sized if I were building it. Those radius outside corners could be mocked up in an open end particle board box. All the radius work could be the same size, just attached differently at the corners. There could be more than one way to build it. Finishing the inside is going to be the difficult task. Danny

[mikeschn]

Those radiused corners are a tricky part, and I believe Andrew came up with a solution for that already. I'll see if I can find it.

Hmmmm, I can't find it right now... I could only find the Tinstream itself...
http://tnttt.com/viewto ... eam#170832

Andrew, did you have a plan for the corners somewhere?

Mike...

[Steve_Cox]

Jim,

You might consider building this type construction on a strongback with an internal jig, like strip boat building.

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[angib]

Andrew, did you have a plan for the corners somewhere?

The two ways I can see are:
- Stave-planking - like assembling a barrel. This would have to use steamed timbers that could be bent around the radius, while still being thick enough to provide a decent glue joint between each stave. This would be very skilled work.
- 'Bread and butter' construction using layers glued together and then sanded to a smooth finish. This would be easiest in MDF, because it doesn't have much/any grain, though multi-ply such as baltic birch would be good too - for ply the end grain will be exposed so epoxy coating would be essential.

Here are some photos of a fairly similar job I did with bread and butter construction:

The slices cut out:


The slices assembled into an armadillo:


The armadillo sanded down to a smooth finish:


This job was a plug for a fiberglass moulding, so the inside wasn't finished, but with something like a 24" radius, it wouldn't be hard to do with an sanding disc in an angle grinder.

The downside of this is that it has to be quite thick (say, average of 3/4") to provide good glue surfaces and be rigid enough to sand, so the finished product wouldn't be light.

In order to design the slices, a CAD program would be useful, but it could be done 'by hand' at a push.

[tddriver]

This is one situation in which "fiberglass over shaped foam" might make sense as a construction method.

[Jiminsav]

well, the skin will be metal..just need some guidance on the frame..
so maybe I should use metal framing..hummmm

[robert johnson]

Well of course the original Airstream is all metal, but a wood frame would be ok. the middle section is flat sides with a curved roof, the front and rear is flat curved around on the bottom half and up the center, and the corners are pie shapes that you can make cardboard patterns keep cutting till everything fits. the corners may only need a tempory frame to hold them in place while you rivet the edges together.


.....Bob

[caseydog]

Those radiused corners are a tricky part, and I believe Andrew came up with a solution for that already. I'll see if I can find it.

Hmmmm, I can't find it right now... I could only find the Tinstream itself...
http://tnttt.com/viewto ... eam#170832

Andrew, did you have a plan for the corners somewhere?

Mike...

LOL, my very first thought when I read the OP was, "Andrew probably already has plans made up."

[Jiminsav]

well, after pondering it all day, I decided to use aluminum angles for the frame..need it to be light as possible as my tow vehicle is a Ford Ranger.

[angib]

Yes, I do have the 'petals' drawn out, but really that's the easy part as you could measure them off in situ. The tricky part is making up the jig on which you will assemble them.

Tinsmith's method of using curved flat bar welded in place is fairly easy, though actually getting the flat bars curved right and welded in the right place is very hard - hence a few wrinkles on his joints, I guess.

I would be tempted to make up a wooden buck over which I would fit and pop-rivet the petals together before fixing the whole eighth-sphere to the framework.

Andrew

[reiltear]

How about a $.99 beach ball of the size you like, wrapped in fiberglass, epoxied, faired, etc., then carefully cut into 8 "quarters"? This way you can also do the bottom "corners" or have spares for the top. I would paint them aluminum color, mount them on the frame and then wrap aluminum over, with a small overlap. Doing it like this would minimize the number of joints, hide the cut imperfections and possibly improve weather-proofing.

PS Inflate the ball first...

[bobhenry]

http://www.sheetmetallayoutcalculator.com/Pages/Pages%20Dark%209850/Dome.html

For you engineers. It's greek to me !

[bobhenry]

How about a $.99 beach ball of the size you like, wrapped in fiberglass, epoxied, faired, etc., then carefully cut into 8 "quarters"? This way you can also do the bottom "corners" or have spares for the top. I would paint them aluminum color, mount them on the frame and then wrap aluminum over, with a small overlap. Doing it like this would minimize the number of joints, hide the cut imperfections and possibly improve weather-proofing.

PS Inflate the ball first...

Or a small weather balloon and a lot of chicken wire and paper mache

[angib]

Or find someone with a forming wheel (US: 'English wheel') who can make them in one piece for you......

Andrew