A tree trunk I modeled for Christmas. I'm posting a little out of season, but there is still two feet of snow on the ground where I live, so that makes it acceptable. Originally I designed it to hold a custom battery pack, circular toggle switch, and a circuit board that controls two individually addressable LED strips. I have also uploaded a version that does not have the cutouts to hold the toggle switch and route the LEDs.
This trunk can fit many different tree models found of Thingiverse. I used the tree that idig3d uploaded (thing:1913982), but you can use many of the trees found here (all printed in vase mode).
I just realized you'll probably have to scale it down to fit most Cartesian printers. I used an Anycubic Kossel and really pushed the limits on height.
I will probably repost the battery pack with more detail on how it works later.
I'll also add pictures when I have them.
I have also added a .step file for anyone who wished to remix this.
Generic Wood fill PLA
Natural Wood Color
I used wood fill for the trunk, and normal PLA for the battery pack.
I just dropped the tree onto the trunk and let it sit there. you could probably glue it if you want to make the bond permanent.
I modeled it in Fusion 360 after a pine tree trunk picture I found online. It took a painfully long time.