RE: [CR]Robotic brazed lugged frames?


From: Mark Bulgier <mark@bulgier.net>
To: 'garth libre' <rabbitman@mindspring.com>, classicrendezvous@bikelist.org
Subject: RE: [CR]Robotic brazed lugged frames?
Date: Wed, 4 Jul 2001 15:40:29 -0700


Many lugged frames were made in brazing machines that wave an array of propane-oxygen "rosebud" torches pointed at the joint until an infrared sensor detects brazing temperature, then a wirefeed mechanism applies the brass. Brass can also be preplaced inside the joint as rings, strips, or pellets.

Not sure when these machines were first employed, but I think many if not most cheaper lugged frames were made with these starting in maybe '85? I know the Taiwanese and Chinese have these machines but I think I remember a "Bike Machinery" (Italian) version too.

Ross had an interesting automated brazing method: tacked frames with preplaced brass were dipped into a molten salt bath that brought the entire frame up to brazing temperature, while also acting as the flux. I assume they modulated the cooling temperature to arrive at a heat treat state somewhere around "normalized".

Mark Bulgier Seattle, Wa USA
> -----Original Message-----
> From: garth libre [mailto:rabbitman@mindspring.com]
> Sent: Wednesday, July 04, 2001 2:58 PM
> To: classicrendezvous@bikelist.org
> Subject: [CR]Robotic brazed lugged frames?
>
>
> Being that this is a classic bike list and that robotic frame
> assembly is decidedly less classic and involves much less
> hand work: Is it possible to braze a lugged frame with
> robots? Are not robots relegated to welded non-lugged,
> frames? Is it safe to assume that any bike that has lugs has
> not been brazed using non craftsman methods? Logic tells me
> that a robot can not braze a lug, as it is more of a eye-hand
> type coordination. Garth