Cheers for the feedback. The unit is still going strong and I'm planning out the next revision as I'm finding this a bit bulky. OK for side-by-side mounting but I'm looking to move away from that and wanting to mount the unit on or under the OTA, meaning a longer narrower design would be better (a bit like a QHY Astrobar, or Prima Luce Eagle2).
Some lessons I've learnt and improvements I'm considering:
Move to an arduino dew heater controller, this should be less bulky in the case as using the stripped down LED controllers made things a bit bulky.
The fuse panel module added a lot of bulk to the unit. First appearances make it look a bit snazzy like a RigRunner but really would have been much better if built onto a PCB - or ommited and had a 1 or 2 fuses where it really counts. My next version will be far less busy looking.
Getting a PCB made is pretty cheap these days - many online services are available, even if you end up with 3-5 of the same board it's still cheap. I'm planning to put much of the 'power distribution' side of things to PCB to cut back on the mess of internal wiring. If it wasn't for the wiring and fuse panel the whole unit would be much smaller and lighter.
I now have a 3D printer as well so have a lot more options when it comes to the case design to put it in. I intend to 3D print an inner skeleton which will be sandwiched between two thin aluminium plates. The skeleton will hold the boards and connectors, the aluminium panels will be tough for mounting between rings and dovetails (with plenty of plastic around each through-hole internally).
(I stole some ideas from QHY - have a look at the internals of the QHY Astrobar here:
)
Finally, a small blower fan like those used in laptops will allow for a slimmer design.
Have fun!