Actually, before we started, I went to Home Depot and bought a 2" circular wire brush that can be inserted into a drill. Tim and I spent some time using it to smooth out the inside of the PVC T. After many minutes with the drill, most of the raised part is gone but there were still some higher spots.
We then tried shaving off some of the other auger piece to make the circumference smaller. That did not turn out so well. During the process, a bigger part of one edge was cut off. Then, one of the parts near one end broke off. Even though it seemed like we cut off quite a bit of the auger, it still sticks a bit in some spots.
We did start assembling the pieces to see how it looks and to feel like we are making progress. See the pictures. A pitcher to hold the dog food would go on top of the blue part (that does not fit on the PVC either). The servo would be attached to the white piece that is attached to the wood support.
I think that I will continue to try smoothing out the inside of the T. Also, I have an extra auger that was not printed perfectly. I think I will use that one instead of the broken one. Hopefully, it will fit in the T if I can get it smoothed down.
Another idea would be to use a plunger instead of an auger. Maybe that would be more reliable. I'll have to see if I can find a device to push a cylinder through the PVC.
Finally, now that I've got some experience with this, I would do a few things differently. First, I would purchase the PVC T and figure out the servo and controller before starting to make anything. That way, I could measure the PVC and possibly adjust some of the prints and cuts. Also, knowing what the servo would look like would help to know what kind of end piece would be needed to attach the servo to the wood support.