Based on the answers provided, the following corrections need to be made to the 3D object:

1. Create a hole in the cylinder that doesn't go all the way through. Currently, the cylinder is open at both ends, which needs to be corrected.
2. Attach a horizontal cylindrical rod towards the top of the cylinder. Currently, the rod is separate from the main cylinder body.
3. Ensure that the cylindrical rod passes through each side of the cylinder. Currently, there is no visible evidence of holes on the cylinder where the rod could pass through.
4. Adjust the length of the rod to be slightly larger than the diameter of the cylinder. Currently, it is unclear if the length of the rod is slightly larger than the diameter of the cylinder.