I couldn’t get the exhaust to open up with donner. I’d have air assist on and I’d watch the valve slowly open. Stopped my job after 5 seconds because I didn’t want to damage anything. Can someone take a look when they get a chance?
If you are talking about the large switch at eye level on the back wall- that one is for the exhaust, and it seems to just move slowly sometimes if the exhaust is being used by another machine at the same time. When I using it last week it still was working and pulling out the air, even when the switch seemed to be moving slowly.
I will occasionally pause my job immediately in order to let the valve to open, then resume it. It can take up to 20 seconds to open fully.
This won’t damage much, but if you have something that will be really smoky, you can pause/resume to wait for the exhaust to open