Monday, March 10, 2014

Pouring Shank For The A8 Crucible

When considering fabricating a pouring shank for my A8 crucible, I thought that a 1" slice of of 6"x 1/4" OD round tube would do the job.  However, the quasi-parabolic shape of the crucible meant that it would be resting on the thin upper knife-edge of the steel pipe - not exactly the best situation.  What to do?

Then I hit on the idea!  Cut the slice in half and "rotate" each slice up and into the parabolic shape!  Some persuasion on the slices with the hydraulic press and I had the two halves of the slice nestling nicely against the parabolic shape of the crucible.

To join the 2 pieces together, I tack-welded 2 pieces of 1"x 1 1'2"x 1/4" rectangular bar stock between the slices and did a test-fit.  A few whacks here and there (remove the crucible first!) made a nice fit for holding the crucible.  After which, a applied the welding to both sides.  The end-result looked like this. 

A bit of "persuasion" here-and-there with the angle grinder and we had a "ring" that fit the parabolic shape of the crucible.


With the "slices" nicely fitted, the next step was to add the shank.  A piece of 5-foot long 3/4" square tube cut at a rough 22 1/2 degree angle nicely did the job.

The next step was to add a handle to the 5-foot shank.  A 1" slice of of 2"x 4" square tube fit the job.
Which after all of this testing, fitting, welding, and grinding, we had a the outline of a pouring shank that looked like the one two-photos above.

A loose crucible loaded with molten metal without a locking mechanism to keep the crucible in the pouring shank isn't exactly a good idea. I was looking for something that would come down on the top of the crucible and hold it in place so that it wouldn't fall out when I tipped the crucible over for pouring.

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