Shutter shock

I've been largely happy with my NexDome since setting it up at the start of this year. It's not perfect but all the issues it can present are generally quite manageable and at the end of the day it sells at a price point that can't be beat. One of said issues is securing it against wind. I only have the dome part of the NexDome rather than the full observatory so can't make use of their wind lock. Instead my own solution has been to tie it down to the observatory structure using multiple coiled springs spread out around the dome ring. It's probably massive overkill but when it comes to a shiny new expensive dome, the peace of mind is priceless. At least it was until one morning a few weeks back when the shutter on my NexDome was blown out clean by high winds! Peace, it would seem, never lasts.

I was just lucky that it happened in the morning when I was awake so I actually heard a loud bang coming from the observatory vicinity and was able to get out there and take my gear down before it all got soaked. I didn't see what happened but it looks like the wind managed to push the front panel of the shutter up a bit then once it was under, the additional lift pushed the whole shutter all the way up and out.

It's suffered a lot of cracking at the rear which I've glued and taped back up as best I can. I didn't stop to take pictures beforehand unfortunately as I was busy trying to fix it up while the rain was coming in 😂 My dome is about 5m above ground so my initial thought was that the damage was done when the shutter hit the ground but one of the rear backstops (that sits against the wheels when closed) also snapped off. Both instances of damage are at opposite ends of the shutter so are unlikely to both be the result of the same impact. I found the backstop fragment on the ground some ways from where the shutter landed so I'm thinking that the shutter got hooked at the backstop and the wind just buffeted it with enough force that it pivoted up and generated enough strain to snap the backstop before the shutter blew away entirely.

I've now secured the front of my shutter with it's own spring tiedowns which should stop the wind ever lifting it again. Let this be a word of warning to other NexDome owners though: secure your shutter. It seems like an obvious step in hindsight but it's an easy thing to overlook. Even with the wind lock in the full NexDome observatory package it only secures the dome but not the shutter itself. I've heard they're now including guards in new orders that sit inside the shutter channel at the top of the dome to prevent it from lifting out. This is definitely helpful and would stop you from loosing your shutter entirely but wouldn't protect against the front lifting and maybe letting a bit of moisture in. If you have the motorized shutter kit I suspect that'd provide a useful bit of resistance to this as well and is probably why shutters getting blown out isn't more common but it's not true protection.

At the end of the day it only takes one incident to put your gear at risk. I was lucky mine didn't occur during the night as the winds were just as high. If it did, everything would've got soaked. Gusts around that period were up around 70-80kmph which is windy obviously but not exactly a hurricane. Even if your dome has withstood strong winds before, a slightly different wind direction the next time around could push it over the edge. Whatever it takes just find a way to secure your shutter. It'll be worth it.