Smatree
A moulded case has very few moving parts, which means almost everything that goes wrong with one goes wrong in the same handful of places. Here is what fails, and what to do about it before it does.
The zip is the only machine on the case
Everything else is foam and fabric. Run the slider rather than forcing it round the corners, and never pull the case open by the lid while the zip is half closed — that is how teeth get bent out of line, and a zip with one bent tooth will split under load every time.
If it starts catching
Clean the teeth with a dry brush first; grit in the track accounts for most of it. A little dry lubricant on the teeth helps. Oil attracts more grit and makes it worse.
Do not use solvents
The outer coating is what keeps the shell shedding rain and looking even. Alcohol, acetone and household sprays lift it. A damp cloth, and a drop of mild soap for anything stubborn.
Dry it open
A case that got soaked outside should dry with the lid open and nothing in it. Closed, the damp stays in the lining and the lining is what the machine sits against.
Watch the hinge on a stand case
The one part under repeated load. If the shell starts to sag out of square when the lid is open, stop using it as a stand with a heavy machine on it and talk to the store you bought from — that is a manufacturing fault and our warranty covers it.
Store it with its shape
Moulded EVA holds its form, but not against a stack of books for a month. On a shelf, on edge, empty, is how these are designed to sit — and it is also how you notice when something is missing from inside.