On Thu, 06 Nov 2003 18:28:30 GMT, Larry Jaques wrote:
On 06 Nov 2003 02:01:37 GMT, (JMartin957) brought
forth from the murky depths:
It's not a question of perfection. What you suggested he do just plain won't
work. It won't even come close. Try it and see. Or, if you want, work out
the math.

Take 1" (example) pipe, cut in half.
Hold end to paper, draw 1" circle.
Fold paper in half at circle.
Cut out 1" x 1/2" semicircular arc.
Fold paper around end of one pipe.
Draw arc.
Rotate pipe 180 degrees, draw arc.
Cut out arcs.
Grind to fit pipe. (requires no math
Weld together.

What won't work?

What won't work is trying to stretch a diameter
around half a circumference. In other words, the
part you need to mark and cut is 1.57 times longer
than the template you're wrapping around it.

Now if you were to leave your template *flat*, and
project lines down from it to the circumference of
the pipe you want to mark, it will describe the correct
curve you need to cut in the pipe.

Gary