Making a mold for a complex shape without 5-axis CNC nor EDM
Sometimes prototyping is crude. An idea for an internal thread change came out of a meeting, but the part is die-casted. and any outsourcing at the time would not have been within budget. We decided that we would cast the validation piece ourselves, something none of us had done before.
In order to get the internal thread, I decided to use its existing mating bolt as a core for the mold. Coupled with some scrap square stock lying around, we had a functioning mold. It was by no means a typical mold with a sprue, runners, or a riser, but it was cheap and quick.
The pieces were then cast out of ZA27 alloy, and machine finished on a lathe. Their preliminary results once tested were better than anything we had made to date.