Summary

Print with 0.2 mm layer height

Caps should be printed with exterior side down
Pack top and Cap end should be printed with exterior side up and use supports

Thread zip tie down square holes between caps and use end of a second zip tie to secure.

OnShape document can be found here
https://cad.onshape.com/documents/e3e104b09b916499499dd397/w/bf6a8868c8f08feebeb42b14/e/0b22ac84614f8081581683f5?renderMode=0&uiState=61d9e4b347bf0557b4d1f78d