TPU casting finger
A ring with a pad on the pulling side, so braid stops cutting into your index finger when you cast heavy.
The problem
Thin braid and a heavy jig open a cut across your index finger after a few hours. Tape lets go the moment it gets wet, and gloves take away the feel of the release.
The fix
The ring prints in TPU 95A. Softer than that and the line digs into the pad; harder and the ring will not stay put. Sizes go in 2 mm steps of circumference, marked on the inside so you can find yours again. TPU is also one of the few common printing materials that stays supple well below zero. PLA turns brittle in the cold, and PETG loses toughness.
The pad is a wearing part. A season of heavy casting goes through it, and a new one takes twenty minutes to print. This one has had a full season of use. The only change from the first version is a bigger radius on the edge that sits against the nail, because that is where it cut instead.
It is a comfort part, not protective equipment. It is not classified or tested as personal protective equipment, and should not be used as if it were.
More ideas
A hook guard that actually stays on
A soft TPU clip that snaps over treble hooks and jigs so they stop catching nets, clothing and fingers.
A rod holder that fits your rail
A parametric holder printed for the exact tube diameter your boat has — not a standard no boat actually follows.
Gear tags for nets and pots that last
Name, phone number and registration embossed into the tag itself — not written in marker that vanishes in three weeks.