Thanks all for the feedback. The clients internal corporate structure dictated that each of the product requirements set out in the product spec document were met before any kind of tooling was purchased. But without the tooling, you can’t do a proper drop test in the actual material with real world molding conditions. Chicken and the egg.
In the end, the client accepted our engineering rational that dropping urethane parts cast from a mechanically similar resin would be an acceptable action short of buying soft tooling. The parts are simple enough that we should be able to discuss gating and moldflow with the toolmaker to eliminate problem areas. We dropped the parts over 20 times with no issue. Our client also has a tumble test that we’re going to run one of the units in for additional testing.
As an aside, shooting 240fps high speed footage on a phone is surprisingly effective at capturing the impacts.