Where to mount electrics/PC in dome?

[tooth_dr]

I'm looking for advice on where to mount kit in a 2.2m dome.

I'm close to being ready to pour a base, and am currently laying out conduit.  I have most space at the south aspect of my current obs (as I'm sure most people do).  But if I mount my PC etc at the south aspect it's going to radiate heat all night up to the main imaging area.  I dont have a bay in my dome, so any restricted to where I can put stuff.  I have a 10" 1200mm reflector on a dual mounting plate, and it extends about 1m from the centre of my current pier (with tube pointing N-W when horizontally placed).

 

Any help or advice or links very much appreciated, as I wont get two goes at it.

 

Adam.

 

 

Edited April 27, 2020 by tooth_dr

[Xsubmariner]

Hi tooth-dr,

I had the same dilemma when I first installed my 2.2M dome, even with an equipment bay. Being over six foot, it would be cramped and not terribly comfortable when trying to image. Early on I decided to operate the system from a separate control room, so a Ketter (plastic) shed was installed next to the dome and flexible plastic pipe used as conduit to route the cabling.  This worked great for a single user but as more friends wanted to experience the wonders of the sky I progressed to a second ROR with separate control room next to the dome. 

Now with a new mount (long counterweight arm) and dual scope setup installed in the Dome, I would assess the space as very uncomfortable for continued occupancy during observation/imaging. It is ok for short periods when I conduct alignment/setting up routines. I use a small wooden collapsible table and chair that can be easily moved to the best position for the laptop.

With some minor modifications the 6x4 ketter shed worked well.

 

 

[tooth_dr]

Thanks Martin. I appreciate the reply. I’m going to have the same dilemma as you, with the mesu, as the CW shaft is about 90cm long.

I currently have a warm room in my observatory - it’s a 12x8’ shed with a 4x8’ warm room section.  It’s on the north side of the telescope section. I have three PCs and monitors in there, and some storage. It’s cosy but ok.

I accept the dome is going to be imaging only, nowhere to sit etc and check things over.  Just maybe a little stool to move around.

Ive no plans to extend it just yet, but where it’s going to be sited, the dome could be extended in the future to incorporate an extra room.  I have the space.

Im currently trying to pin down where to route the ducts and mount the electrics etc.

The other option is to install a raised floor over the concrete, just enough to run cables below it.

Looking the feedback and views prior to pouring concrete.

 

Thanks

Adam  

 

[Xsubmariner]

Hi Adam,

In my dome I ran conduit to the centre of the pier base and to the north side of the dome where the 12v DC distribution is located and to dome controller . You will want to consider what services the conduit will support to prevent mutual interference.  My AC/DC supplies are separated from signal cables.

Here is a list of the conduit/services/cables I have run:

Here is a list of the conduit/services/cables I have run:

2x conduit from outside Control Room (CR) to Pier Base(PB), 2x conduit from control room to North side Dome (ND), 1x conduit from North side outlet to Pier base. 1x small conduit from control room to location of Dome Automation (DA) controller.

Conduit 1 CR to PB; 

AC supply circuit cable (all RCBO for safety) to sockets on pier surround that support; electric wall heater on pier base with thermal control, AC PSU services at pier.

Fibre optic cable x2 from CR to imaging system, supports Vhigh speed USB3 service via converters.

Conduit 2 CR to PB;

3x 5M active USB 3.0 cables.

1x 5M active USB 2.0 cable.

1x Cat 6 cable for Ethernet.

1x 5M Serial cable (RS232).

 

Conduit 1 CR to ND;

AC supply circuit cable (RCBO) for dome wall socket services; PC laptop, monitor, Security camera PSU, dehumidifier, etc.

12V DC cable x2 (30A) to dome distribution board.

 

Conduit 2 to ND;

Cat 6 (Ethernet) x2 for; security camera, dome monitor (vga over Ethernet).

Telephone cable.

 

Conduit ND to PB;

8 x DC (10A) cables to feed DC out let’s on Pier surround.

3 M USB2.0 cable for Polemaster to monitor/PC

 

Conduit CR to DA;

10M serial cable (RS232) to dome controller.

 

Key dome environmental considerations:

There will be some water on the floor in the morning due to condensation, the dehumidifier helps. I drape a breathable cover (old Motorcycle cover)  over the equipment/pier and I find that the low wattage (40W) pier mounted wall heater sets a thermal layer under the cover that greatly reduces condensation on the equipment.

All my processing equipment, AC distribution/UPS and 2 x 35A DC PSU’s are kept in the control room which is insulated and dehumidifier.

Security- I have a fitted security system in the complete installation with door contacts and motion sensors which is connected to the telephone. In addition there is another seperate security camera in each dome, control and ROR compartment, these use Ethernet cabling to control room and underground cable back to the house (WiFi is too easy to jam)

Don’t forget to run spare backup cables, just in case of failures. Obviously not everyone needs everything I have used but I have already utilised some of my spare capacity moving to a dual rig 4 x camera setup in the dome. 

I hope this helps in your thought process. 

 

[tooth_dr]

@Xsubmariner thanks Martin.  There is more than I need but I plan to throw in a couple of empty ducts for future use.

I have just put the dome together inside the garage this afternoon so I’ll try the wiring sorted as much as possible. I can’t get concrete at the minute due to CV-19.

[skybadger]

Hi 

i put mine at the south side of the observatory, which is cramped when the scope is homed to the pole and frequently gets knocked, so I need to remember t park up east/west more often. 

While I take your point about heat, most pcs these days don;t put a lot of heat out and I dont see it as slot seeing during taking video of the moon for example.

However, I do think I'd think seriously about putting it on the north side of the dome since there is less use of the scopes from there, even when viewing the meridian. 

But you would have to think hard about the risk of disturbing them during an imaging run whhen they are most likely to be camera end to the pc/workstation as you image across the meridian. That was what made me put it on the south side originally. 

Mike

 

 

 

[Gina]

My imaging electronics is right beside the cameras on the dovetail bar but I'm using the Raspberry Pi.

[skybadger]

good luck running a dome from there. without running all the electrics to it .

 

 

[old_eyes]

When I was planning my observatory and thinking about a dome, I was warned by a couple of members (can't remember who) to watch out for condensation running down the walls. Something I had not considered. Some careful thinking about where to put electrics and computers is required.

[iapa]

what do people do to cp conduits to prevent water ingress?

I will be running a specific ring from the house to the ops, and don't fancy (OK - Hourinsg Directorate) drilling a massage 4" hole in the the outer wall .

[Davey-T]

4 minutes ago, iapa said:

what do people do to cp conduits to prevent water ingress?

I will be running a specific ring from the house to the ops, and don't fancy (OK - Hourinsg Directorate) drilling a massage 4" hole in the the outer wall .

If it's just 240 volts power then SWA (steel wire armoured) cable is used, either buried, nailed to fence or through the sky on a catenary wire.

Dave

Edited June 9, 2020 by Davey-T