Sentinels can take Longshot plunger tubes or equivalent 100ml syringe tubes.
This is an experimental replacement U-loop piece for total replacement expanded plunger tube mod and doubles as a replace/repair piece too. Don't worry too much about the thin wall, that's mainly for guidance. This will all be Devconned on and automatically reinforce.
It's recommended you print this in ABS, PETG, Nylon, PLA+ etc. for any prolonged or high spring usage. The current model is slightly slightly scaled up to account for ABS print shrinking. Tested up to 12kg and holding on ABS.