This is just an addition to compost shredder by thymark. I've used it to shred apples for cider and some kind of top container/intake was required for this task.
This funnel is similar to other already existing on Thingiverse, but it's printable on standard 20x20cm print bed and uses already existing screws.
It's seems a bit bulky, but when printed with small infill it doesn't matter. Just make sure it's mounting legs are printed fine (this is a weak point here).