That’s a good point I missed. Closing the cap when you’re not using the printer could help mitigate against a leaky bite valve.
if I understand correctly you say the vent cap needs to be closed because the cartridge empties itself otherwise due to the resins weight
Really never happened to me
Did it to anyone?
The bite valves were slightly notorious for problems. I recall seeing some reports of leaks (e.g. 1, 2). Lots more reports where the scoring was too shallow and customers were instructed to use a knife to finish the cut through the material. I’m guessing the manufacturer had trouble achieving the desired control over tolerance and Formlabs may have shifted the spec slightly to the conservative side for a while. It’s also been proposed the rubbery material is sometimes self-healing.
I expect things have improved since then, as I haven’t seen chatter about this lately.