The new model had some serious problems around measurements. The slots which the ears would have attached to were printed too small, either as a result of poor measurement or lower than expected printing resolution, probably a combination of the two. To fix this, I printed several variants of the ear slots to help me determine what size they will need to be in the final version.

In doing this, I also realized that the structure I created was not as reliable as I expected. The very circular internal chamber which the screw head rotates within makes it difficult  to lock the ears into place. Future versions of the body will incorporate a different attachment mechanism that should let the ears lock into place better.