Big Bamboo, how'd they do it?

[nuge]

Saw this in a brewpub, the pipe is about 12" in diameter. Any ideas as to the techniques/tooling?

[urnesBeast]

I have seen much smaller scale pipe done on a hydrolic press. How long is the pipe? The Foldforming book has examples of this in copper.

-Doug

[matt87]

I've seen a video of doing this but only a few inches diameter. The guy in that video used welded steel pipe. He formed the node boundaries by taking isolated heats by rotating the pipe in a gas flame and upsetting. He also used a spring fuller to create a groove but I don't think that detail was included in the linked image.

[ptree]

I make bamboo. I start by necking down a narrow area on a guiletine tool. I take another good local heat and upset back on itself. Makes a nice bamboo. I have found that pipe that has laid outside for years and is heavily pitted gives a very nice added texture. I have made bamboo up to 2" pipe this way.

[Dragons lair]

ptree, That outdoor pipe also makes the best catails.
Ken

[Frosty]

Matt:

There's a good chance the video you're talking about was done by Ornamentalsmith, Bill Roberts. He did Youtube demos on a couple methods for making pipe bamboo.

I used to work at a place that did what was done to the pipe in Nuge's picture to make "flex" pipe and flexible pipe for aircraft apps. It's done on a mandrel with inside and outside grippers.

The tubing is gripped on both sides of the area to be formed and hydraulics press it together. The material can't fold inwards because of the mandrel so it folds outwards into very precise ribs. Then the tube is slid onto the receiver mandrel which expands to grip it and the other mandrel grips the fresh section and swages it into the next rib.

The process is very fast, the max diameter our machine would do was 6" and it'd stack ribs 1 1/2" high nearly touching at about 2-3 per second. The faster the swage the more precise the results.

The 12" pipe pictured is obviously a reject that found a home outside the scrap yard.

Frosty

[ptree]

Gragons Lair, I make lots of at tails, and indeed it gives the best cattails.