Can look at those thank you. Looks like Tinkercad actually does have some threading options and that’s closer to my comfort zone. Appreciate all the great comments here. The more I look into these options, the more I think for the routine, shoot I lost the cap for these gummy vitamins or paint bottle type situations, the more I like my tpu stopper idea for simplicity. There are more variables than I realized on getting a cap to fit it appears.