Long tapered tubes

Jan 02, 2007 17 Replies

Yesterday I spent quite some time (unusually) as a passenger on a motorway journey and my mind wandered to looking at the forest of long tapered lamp posts wondering how the heck they make them.



So how do you make a steel pipe of perhaps 30 foot length with a 2:1 taper over its length?



AWEM


If you've got hundreds/thousands to do, make a tapered mould, start with a parallel tube and expand it by ? hydraulic/explosive forming or a tapered mandrel?? Pure guesswork, not something I know anything about.

Next guess??

Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Many of the posts here are rolled out of sheet metal and welded.

Nick

Found this: it may shed some light...

cheers Guy

*groane* shed some light...

Surprisingly, I found that an interesting read. The U-shaped supporting ribs and VCDs is clever stuff.

Zed

Guy Griff> > Yesterday I spent quite some time (unusually) as a passenger on a

supporting

ah ha - now we know - thanks - cunning, these orientals !

AWEM

Just think - with one of those tubes you could make a gin barell to fire tapered bullets

Regards, Tony

Firefox locks up when I try to open it :-(

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Were you thinking of making one (or several) at home? Surely this would be an interesting exercise in casting.

Russell

Well now lets see, traditionally it would have been:

- form plug/core from loam/cowdung mix on central spigot previously wrapped in straw rope and dry

- form wall thickness by coating above in beeswax and leave to cool

- apply further coating(s) of loam/cowdung mix and straw rope and leave to dry

- erect in pit and slowly heat to melt out wax and bake mould (a VERY deep pit !)

- melt iron, hope its got enough fluidity, and pour

- demould result and toss (at least) 50% back as scrappers

(of course you could use the slightly more modern Stanton & Stavely method of spinning a female mould without a core but that's too easy!)

Russell, no I think on reflection perhaps not just yet

AWEM

Tim,

It's a PDF. Download it separately (right click on the link, and 'save as'.) Open from where you save it, don't let firefox try.

I would recommend installing the upgraded version of Adobe Acrobat, but it's an enormouse download, forces a reboot when it updates itself and is generally a pain in t'behind. If you have a quite new and fast PC it's not too bad.

Ed

Neil Ellwood wrote:

If running firefox in Linux as I am try changing the action to open with ghostview.

My firefox always left me with a blank screen so had to save file and then open up seperatly. Now it does this automatically.

If not Linux sorry for the bandwidth.

Cheers Adrian

Suse10

Works fine for me, Firefox Version 1.5.0.9 (20061207) running on W2K+SP4.

It did work for me after at least four failures, one of which needed a full reboot. Same setup as yours.

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

^^^^^ ^^^^

And a very appropriate method it is too, for posting to this newsgroup :-)

I sometimes post unintended jokes. :-)

Nick

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