Sirius Domes

[matlud]

Hi,

Does anyone know if Sirius Domes are manufacturing again after the terrible fire last year?

Cheers,
Mat

[Peter Ward]

Yes they are.

[matlud]

Thanks Peter, that’s great! Are they still as highly regarded as in the past? I see scopedome has become popular but I am looking for something a bit smaller and their 2.3m dome (with full automation) would be perfect 👍

Cheers,
Mat

[Peter Ward]

Owen is doing a great job on the domes.

While not inexpensive, the Sirius product is extremely well made and will last for decades. Mine is now some 35 years old, and while the gelcoat is getting a little thin in places now, otherwise no problems.

Scopedome are also well made, but the revolving "walls" would be a PITA.

I'd strongly recommend if you go down the Sirius path that you also order the pop-out wall storage panel option. (At least two). They free up floor space for your gear, e.g. UPS, PC's etc.

[matlud]

Thanks Peter -sounds good and will do on the storage bays 👍 I’m thinking I will run a couple of conduits through the slab to the pier so I can get power, USB, Ethernet there without having cables on the floor, so the bays would be useful. How tall is the pier you have in your Sirius?

[muletopia]

Hello Mathew,
My Sirius 3.2 sits on a concrete slab in which I cast two drainage channels.The larger one brings in power from solar powered battery.The mount is on a big concrete block isolated from the slab carrying the dome.


My pier is 1.5 metres tall .


The floor is covered with interlocking plastic grating about an inch deep which are overlain by interlocking EVA tiles to about an inch fro the walls. I have no mold or dampness problems with this arrangement and a pot of Zilch dehumidifier pellets.

I have three bays and this is probably more than I need.

If you aim for automation make sure that the floor slab has adequate foundations to maintain its position and its surface horizontal.
Cheers
Cris

[matlud]

Thanks Chris -that’s great info on the floor and pier. I was going to do an isolated pier foundation of ~1 cubic metre with a metal pier on this, and a concrete slab surrounding this on crushed gravel base. I might have to do some additional deeper corner foundations on the slab to help keep that all level… Do you have your dome automated?

Cheers,
Mat

[thebonz]

The sirius dome is a great product. My dome I bought second hand is also about 30 years old. Cut and polish the gelcoat and it looks great, I mounted my pier in a bed of concrete and mounted the dome on a merbu decking platform that is separate from the pier. Dome in background of the pic.
This works well for me.
Cheers John

[Peter Ward]

The answer is 42....inches that is.

I hope it's not a monolithic slab...you'll get vibrations is you don't isolate the
pier from the slab floor.

[Startrek]

Can I give a plug for the 2.2m Nexdome
I’ve just arrived down South after the NSW 2 month deluge and my rig and all other ancillary gear inside the Nexdome is spotless
My neighbour mentioned that they had 60km/hr winds and driving rain, he’s right I’ve got water damage in the lounge room and dining room ceilings ( above the roof valleys ) Lodged an insurance claim today
So the NexDome is definitely water tight !!!
The boys at Sidereal can set you up with a 2.2m NexDome or a bigger ScopeDome with Voyager software to automate the rig
I’ve had mine for a year

[matlud]

Thanks John, sounds like they are built to last and your obs looks great!

[matlud]

Thanks Martin, I have checked out NexDome as well, the size is good and your experience would suggest pretty resilient as well �� Scopedome looks good as well, unfortunately the 3m is just too big for the side garden at our holiday place where my wife has given planning approval, and the 2m is maybe a bit small for future equipment (although having it arrive assembled and being plug and play is very attractive…)

[matlud]

Thanks Peter! The concrete pad will be ~200mm above ground height so I am planning on doing a separate foundation for the pier -thinking 800x800x1200-1500 or so with wire cage, and just forming the top 200-300, so the base of the pier foundation has good contact with the undisturbed soil. I will try to get the concrete as smooth as possible and drill some anchors for the steel pier. Still deciding if I use some washers if I need to shim the pier or I have seen a block of treated ply used under the pier which is compressed down…

The rest of the slab will be separate, maybe with some slightly deeper foundations at the corners to help keep it level. I will run some conduits through the floor slab and the pier foundation for cable management. This is my first obs so any tips much appreciated. 👍👍

[Startrek]

My 2.2m NexDome will easily fit an EQ8-R pro and 10” f5 CF Newt which is arriving in 6 weeks ( I currently use an EQ6-R and 8” f5 Newt )
Mine is located in a narrow backyard on a Merbau hardwood deck with piers underneath ( unfortunately my centre pier can’t be used as it’s too narrow , only 250mm dia , so I use the other 3 tripod piers and it’s fine. I can jump up and down inside and PHD2 doesn’t blink and eye ) I don’t stay in the Dome anyway I image from my study in the house.I made up my own Dome rotation control system ( electronic relays, switches and timers etc..)
NexDome say you can fit a C14 , I think Dylan ODonnell uses a C11 in his

Cheers
Martin

[h0ughy]

Not quit true with a massive 5 cubic metre base over a metre thick I don't have any issues like that. Tonnage;)

[muletopia]

Hello Mathew
No I do not have automation.
My ob is on the geologically ancient Yilgarn block which has very deep weathering.
Thus a clay subsoil to a great depth.


https://www.iceinspace.com.au/forum/showthread.php?t=135400


The link above describes the pier and its placement.
Even this large chunk of concrete moves around with the seasonal change in soil moisture. This is not a problem, it just requires polar alignment every month or so.
For photography the pier is rock solid, with a Mesu 200 MK1 on top guiding with PHD2 easily accommodates the polar alignment error,(down to .25 seconds RMS on a good night..
My floor is a 3 metre square , in placing it I did not make sufficient foundations and it has acquired a north/south slope.


Chris

[AstroJunk]

Even with a simple 4" slab, neither my 2.3m or 3.5m observatories induce vibrations in the mount whist turning. I can get a vibration if I jump up and down, but that isn't part of my imaging workflow :rofl:

The downside of the otherwise superbly built Sirius 2.3m dome is that the aperture is rather narrow by modern standards - these were designed when an 8" SCT was a monster of a scope. I did have a 14" in mine, but it was hard to keep it central even with automation.

[Peter Ward]

QED.

Poison is just the dose. ;)

I chose not to mechanically couple my pier to the dome floor.

BTW Mike and Trish's (non-Sirius) dome (I recall they had some building progress shots) is definitely one of the more impressively planned and engineered domes in Oz.....if you needed template, theirs is flawless.

[xthestreams]

Quick take from my experience. Sirius and Scopedomes both have a “premium” finish and feel, but I can’t comment on current pricing, either would make a fine home.
My Nexdome by comparison is utilitarian and functional but suited my purposes and budget at the time of purchase, but it does lend itself toward someone comfortable with tinkering to setup and fine tune issues resulting from less than precise manufacturing tolerances.
The benefit is that it’s as close to a flat pack dome as you’ll get and to Martin’s point, it holds up to weather well.
One thing to note, if disturbing the neighbors or co-habitants with the sound of the dome moving at night is a potential issue, then the Nexdome is notoriously “clunky” and might not be the best choice, in my experience.

[matlud]

Thanks Martin, your obs looks great (and very tidy) 👍👍 The NexDome size looks great too, I think I saw someone fit (just) a 14inch planewave CDK in one and I don’t see going any bigger than that 😀

[matlud]

Thanks David, I have deep clay where I am so this could be an approach 😀

[matlud]

Thanks Chris. I have deep clay as well so have the same problem. Maybe I’m better to try to go deeper with the pier foundation… will definitely look at some additional foundations for the slab though, that’s very good advice. Thanks, Mat 👍👍

[matlud]

Thanks Jonathan! I’m considering whether I hedge my bets since I’m on clay and do a foundation that is T-shaped in cross section so I have a deeper element as some floating towards the surface that might help resist any sideways movement. Good point on the slit width -I see astrodomes have a 900m slit for their 2.4m dome. Thanks, Mat

[matlud]

Thanks Peter, I’ll see if I can find that thread. Cheers, Mat

[matlud]

Thanks Paul. The NexDome pricing is very attractive. Luckily my obs will be well away from neighbours 😀 I’m hoping to avoid too much tinkering - the best option in that regard is the Scopedome 2m which comes full assembled so pretty much plug and play. The 2m is a bit smaller than the other options but has a similar slit width. I’ll be running it remotely and it might just work hmmmm.

[AstroJunk]

I'm on clay rich soils too and had a level platform cut and compacted for the astro-toys. Amazingly and despite over a metre of rainfall in three days during the recent flooding events, when I went to polar align the big scope, it had only shifted by a few arc seconds. The larger dome went in 10 years after the smaller on, so the ground had plenty of time to settle!

Our house had some decently deep pining to keep it from moving like you suggest - a 10" auger hole sunk as far as you can be bothered will do the trick. Dig out a few other holes in the garden at the same time and fill them with decent soil - it's a great way to establish shrubs quickly :)

[h0ughy]

i live in a swamp;)

https://www.iceinspace.com.au/forum/attachment_browse.php?a=188365

https://www.youtube.com/watch?v=laOBvo861aQ

[raymo]

If you live in a swamp perhaps you should change your name to Roughy.:)
raymo

[Peter Ward]

I have professionally installed a few observatories around Oz and recommend the following for a Sirius dome.

To remove any possibility of induced vibration, provide ventilation and reduce condensation and reduce local seeing from the thermal inertia of a 12+ tonne slab ( I'd suggest the thermals would be impressive in summer) mount the observatory on low deck.

If you really want to get fancy, make it really high deck to get above ground turbulence/seeing ( Perth Observatory, did this in extreme with their 61cm Lowell telescope..amazing what a little support , read $$$, from NASA can achieve) .

The pier should be isolated from the deck. AC sheet ( used in bathroom floors) or Modwood are good weather and fire resistant low maintenance choices for the decking surface. Make the deck wide enough to allow you to walk around the dome for cleaning, servicing. Nothing too hard about this, but certainly worth getting right at the planning stage.

[xthestreams]

One thing I should have pointed out is the creepy crawly factor. In the case of my Warrambungles dome, the mud wasps will find their way into just about any opening into your dome or RoRo - same goes for spiders (which the mud wasps hunt), this is another area where the Sirius and ScopeDomes offer an improved degree of protection - the Nexdomes are far more open to dust ingress and bugs.

Not matter what you go with, strongly recommend budgeting for either a dehumidifier (plumbed into the dome so you dont have to empty it) and/or a chiller (ideally this can also dry the air), depending on how warm your dome gets. It sounds extreme, but as Peter mentioned, heat (and dew) is your enemy.

[matlud]

😂 Nice looking slab though -very solid! My site gets pretty soggy over winter will need some good foundations 👍

[matlud]

Thanks Peter. I will definitely look at having the pier foundation separated from the dome support, if I use concrete will looks at some silicone sealant between the 2 slabs for moisture control. A deck is an option but the ground gets fairly wet over winter so moisture control is a consideration. Not sure if I can get planning approval for the dome to be any higher than it is 😂

[matlud]

Thanks Paul -I am not a fan of spiders so that is a good point in favour of Sirius and Scopedome 😂 I am thinking about putting a small split unit heat pump in there for controlling temp and humidity. I have been looking at Lunatico Dragonfly for an IP controlled power switch to control all of this.

Cheers, Mat