Not that I would actually try this, but would you think that an interrupted
cut would work? that way you might get away with a blank just a little
larger than the radius, for a 90 degree bend?

I once made (still have, now that I think about it) a 90 degree die to bend
sand filled, annealed 1.25" 6061-T6 16 ga. tubing, out of plywood. Worked
just fine, the radius of the bend was about 6". Bent the water pipes for my
race car. Here's a picture of my race car and I at VIR, for those who might
be interested.
http://www.mikekellerphoto.com/Event.../DSC_2676.html


Brian


"Roy Jenson" wrote in message
...
As much as I liked the dice discussion.................

Making the dies in a lathe works fine but has a few practical
problems. The shop I worked at made many of them.
Things to consider:

1) the starting blank need to be a solid chunk at least 1.5x
times the diameter of the tube and the full diameter of the bend.
This is not an issue for a 1/2" tube on a 2" radius but a 2"tube
needs a 3" thick slab around 12" in diameter. (assuming a 3d
bend) Youmay be able to get by with a welded up or bolted up slab
but it is fragile and tends to leave nasty tooling marks in the
tube.

2) the groove should be round. You can approximate this and file
out the rest but the good way is to use a spinning tool mounted
in the tool rest. It has a pivot, a long arm, and a cutting tool.
The blank is hollowed out, the pivot point is moved to the exact
centerline of the tube, and the arm is rotated back and forth.
Works slick the tool ran around $1000

3) long term use requires heat treating. A whole 'nother story on
big chunks of odd shaped steel.

Someone posted an excellent set of links to tube bending theory
in the last few weeks. Take a look at those.

Cheers.

Cass wrote:

Thanks, Ernie.

Is there any practical reason one can't simply make what they need on a
lathe, other than the proper dimensions?

Cass

"Ernie Leimkuhler" wrote in message
...
In article , Cass
wrote:

Does anyone know where I could research for pipe bending dice that
are
used
either for manual or hydraulic bending?

I guess that I could make some on the lathe but not sure of the
dimensions.

Thanks

Cass




The cheapest method is to simply buy a 12-ton pipe bending set from
Harbor freight.

I know of no simpler of cheaper method of getting the die sets.