Dear Al,
Earl's catalog has the proper tool for this, fits inside the tube and then several ball bearings expand out as it is

rotated

forming a perfect radiused bead. Sizes from 3/8"-2" with walls from .035"-.065"
...Chrissi

As I recall someone made one of these things. As I recall I tried it and it did
not work very well. Perhaps the tubing was not dead soft.

http://www.earlsperformance.com/html/

Their web site sucks. What is the price Chrissi?

Paul Lamar

Sorry Paul, I can't take responsibility for their web site =)
The price list I have is 1994 ish $49 for jobbers price on 1.5"
...Chrissi

Here is a picture of the tool bill Atkins built.
Does the Earl's tool look like this Chrissi?

Paul Lamar

Yes, thats the beast, or at least very close to it.
Would be almost as simple to make. operates as simply as a pipe cutter; you tighten the center screw to get the ball bearings to
go outward, you turn the whole thing to run the bead, repeat till you have the bead you want. Blind guess is the center screw
has a 15-30 degree chamfer to give some finess to the incremental control of the expansion as well as a very fine pitch to the
threads.
If you want to do the same thing with common taps and dies to make a similar one you can load the channels up that have the
bearings in them with a series of several bearings, like links in a chain. If you put wheel bearing grease in the channels you
will not need to stake the bearings outlet holes to prevent them from coming loose.
... you follow this right?
.....Chrissi

I need a 3D drawing.

Paul Lamar
 
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