I've taken the original stl from the maker and used Bambu Studio to cut it up and make the required setup I needed for my shed to complete a full 360 around the shed including a down pipe 

Unfortunately the creator didn't share the original step file so I didn't have much to work with however it all works and prints nicely for a rain gutter. 

I've included the original as well as the following

Extended length

Mirrored 

Down pipe

End caps

90 Deg corners in both directions

All items clip to together in the same way the original did. I've used pipe glue to join and seal so it doesn't leak.

You may also be interested in the first flush down pipe pictured here: First flush rain collector for shed by Noisy Boysie MakerWorld: Download Free 3D Models

It attaches to the down pipe section and allows you to remove and filter out the stuff that comes off the roof without putting it in the water butt or rain barrel