Shout out to TechX03 for the original model. It was close to what I needed but the poop bin was too small. My X1C is inside a fume box so I needed a larger poop bin that was easier to reach and held more waste. Also added some fillets to the chute.
The original back screws that attach the chute are a coarse plastic thread, but they are too short to secure the chute. I discovered that the Bambu packing screws that held down the bed were the same threads, they just needed to be cut off to 10 mm. Otherwise, TechX03 indicated he used M3 x 12 mm to attach his chute.
**V2 model now available that allows original printer screws to be used for mounting:
https://makerworld.com/en/models/244527#profileId-261018