The old dryer vent on my house was cut and taped in place to fix a gap between the pipe and vent cover. In the years since this fix was made by the prior owner, the tape has peeled away, allowing lint to stick to the exposed tape and clog the vent.
I removed the duct tape, then printed a replacement that connects to the cover and slides into the pipe, providing a better fit and less chance for the lint to clog the airflow.
UPDATE: The vent cover isn't a standard size, and designing a model to fix right was proving difficult, so I had to seal a minor crack between the model and the cover with caulk.
The author hasn't provided the model origin yet.