New Role-On-Role-Off shelter for the gear on the balcony.

Update from 21.08.2022: Next evolution - Main controlling unit

Since the cable mess and the number of boxes became by far too much I had decide to consolidate all the controller components and add an option to switch remotely all power supply units (PSU).

The housing:
I have chosen a NEPTUN36 an IP65 3 rails DIN housing with integrated ventilation and IP65 cable break outs, so I can be sure no moisture creeps in.

Interior of the housing:
It contains a more powerful 5V PSU serving the built in RasPi4 and external components (network switch and SkySQM). It contains also a 12V PSU powering the Lunatico AAG Solo / Cloudwatcher.
Of course, to make it safe it has an RCCD and two more fuses for each curcuit.

Shelly Pro 4PM Pro LAN / WiFi Switch:
But the highlight is the Shelly Pro 4PM Pro LAN / WiFi Switch. This is extraordinary cheap (approx. 80EUR) but provides an enormous functional spectrum. It can connect via LAN, BT, WiFi (client and AP at same time) and many things more. It can be also controlled via cloud services, which I do not use for security reason. I just use any browser (mobile or PC) to operate it. Moreover, it can be scripted via MQTT and other protocols.
Two of its four outlets control the two external PSUs (24V mount and NUC, 12V for all other components). The other two outlets control the internal PSUs, serving the RasPi (5V) and the Lunatico AAG Solo (12V).
With this setup I am able to bail out in the worst case and reset everything.

The RasPi controls a 4 channel relays board and switches the heating, dehumidifier(s) and radial fans, I have described before.

The Intel NUC:
The NUC is configured to boot automatically when power is restored. So it is ensured it is coming up as soon as power is back and I am not dependent on WakeOnLan, which might fail, if the switch was also rebooted and its MAC table was purged.

If You have any questions I am happy to answer them either in comments or PM.
Thanks for your interest.

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Update from 18.03.2022: Change after 6 months of experience

All in all the project was a full success in any aspect, but like always, you learn and improve thing ATS. ("Astro Tinkering Disease" )

Revision D -> G: 2" Tube inserts for focuser
The capacity of the 2inch absorbers was too little. I have printed 2" inserts which can contain 70g of silica in bags which last at least for 2 weeks. I have printed this for the TEC and CDK. Additionally I have added a temp and humidity sensor to each inserts plus sensors in the CDK main mirror containment and the CDK's light baffle and TEC’s dew shield. there I have also placed 70g to ´190g silica bags. The sensors log via a RasPi the data to a database. So I have full control and see when silica needs replacement. For that I have created a web dashboard (revision H), where can I see in one glance all crucial data. Hr in the TEC and CDK tubes is between 15% and 40% Hr. The TEC tube drops below 10% with fresh silica.

Revision E -> I: Radial Ventilator
The inline ventilator has been replaced with a radial ventilator which is not so noisy. The air tube was not required anymore, since the fan is so powerful that it circulates The complete volume within seconds.  

Revision K: Dehumidifier
Since humidity was quite high during cold season I have added a dehumidifier. Important here was to find one, which can be operated at lower temperatures. This one works in a range from 5 to 40° C and can remove 18l/24 hours. If it is too cold it can preheat and defrost its condensate. The device is controlled by the RasPi which is switching it on and off.
This device is a bit oversized and actually needs more volume to work properly, but this was the smallest one to fit the requirement concerning low temp. After 5 minutes the Hr drops from 90% to 40%. So 5 minute runs are enough every few hours.

Revision L: Heater
In order to keep everything above 0°C I have also added a heating tube with 130W. Since the cover is not very air tight, and air circulates, it is only sufficient to raise the temp by 4-6 degree. But this is sufficient. Also the heater is controlled via the RasPi. It also pre-heats before the dehumidifier is turned on.

Please feel free to ask questions in the comments or via PM.

Many thanks for your interest!

Clear Skies
Rüdiger

Links:
Ventilator: https://de.trotec.com/shop/turboluefter-tfv-10.html
Dehumidifier: https://de.trotec.com/shop/luftentfeuchter-ttk-60-e.html
Heater: https://www.ebay.com/itm/115053843564?hash=item1ac9be546c:g:oZEAAOSwbC5hbrjG&var=415135923316#rpdCntId



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Original text:

Since I am always keen on watching other's gear and solutions I want to share my latest construction to protect my gear.

Since the equipment became bigger and more I had to extend the 2 year old wooden construction ( https://www.astrobin.com/cd88ig/?nc=&nce= ). Since everything stays outside 365 days per year (except the electronics e.g. power supply, NUC, camera and 10 Micron controller) it needs to be absolute save and stable, but also moveable, extensable and well air conditioned.

The frame:
The frame is made from 45mm x 45mm aluminum profile. For the edges a 45° rounded profile was used. The outer dimensions are 140cm x 90cm x 170cm (W x D x H). The size was carefully chosen in oder to prevent any contact points between gear and canvas to avoid any condensed water to pour from the canvas into the gear.
Total weight 15kg on ball bearing roles with locking breaks. The hole frame can be moved with the finger tip with ease.
One side has no beam in the middle so this side can be open and pushed over the complete setup.
It is even high enough you can huddle under and work on the equipment while it is raining.

The canvas / cover:
The canvas is a truck canvas crafted by a local saddler which is UV resistant. it weights 900g / square meter. It is heavy enough, that it will not be lifted by wind gusts. It has two air inlets on the long sides and 3 pairs of zippers. So 3 sides can be opened. Either for moving or venting.

Ventilation:
Since it is sometimes not sufficient or possible to open one side for venting, I have attached a ventilation tube inside. To this I can plug an industrial ventilation system (1000m^3/h) which can operate in push or pull mode. A second fan is also inside the shelter, because the big one is too noisy for nightly use. Both are controlled via a RasPi which measures humidity and temperature. It switches both ventilators. Software and hardware are self made (but also quite simple).

Moisture control:
For the CDK's light baffle I have printed a TPU dust cap which also serves as cover for darks. It is painted inside with Mosou Black. When parked I put some desiccant bags inside. Also into the cap of the TEC140.
Additionally  I have found some desiccant applets (30g silica) with an indicator and fitting size for the 2" eye peace holder. So all optics are kept dry.

Additional cover:
I have found by coincidence a cover for beach chairs with precisely the same dimensions, which is sold by "Tchibo" for little money. So I have a second light pull over canvas for the winter to keep some warmth inside, or in case of a Thunderstorm. You can see it on the photo with the ventilator.

Costs:
Surprisingly cheap - compared to other solution where the word "Astro" is printed on
Frame: material, cutting, connectors, shipping… approx 300 EUR
Canvas: 190 EUR and a beer
Desiccant: 17 EUR per applet (regeneration possible)

I hope, I could provide some ideas.

If you have any questions, feel free to ask

Clear skies
Rüdiger

PS: I will update the text continuously with answer to questions and/or experiences made with it.

Links:
Frame work: https://easy-systemprofile.de/
Canvas: http://www.zahner-planen-nuernberg.de/
Desiccant: https://de.rs-online.com/web/c/heizung-luftung-klimatechnik/klimaanlagen-und-heizungszubehor/silikagel-und-trockenmittel/
Cover beach chair: https://www.tchibo.de/premium-schutzhuelle-fuer-strandkoerbe-xl-p400164660.html