Checked the levels today and those are not too bad. One bad patch but plastic packers will sort that out. Only a couple of millimetres out of level here and there. I am sure some packers will sort that out.
So you are planning to have 2 observatories there - one for your short focal length refractor and one for longer focal length?
Nice setup plus you've got the incredible location with the excellent seeing.
Greg.
Yes Greg, two observatories for wide and narrow field. The wide field will be in the roll off roof and I will also do planetary imaging in there from time to time. So I have set up that scope so I can simply take it off the mount at any time. The narrow field rig will be in the dome.
Eventually I want to have a 17" or something of that size in the dome and something like a fast newt or RH in the roll off roof. Aperture is really needed to get a good S/N ratio in a shorter time frame. However as you know that takes lot of money. So for now I have the imaging trains with the mounts and some acceptable scopes.
The seeing really makes the location. No wind at night with very still seeing and dark skies. Its almost perfect. The only down side is the proximity to the water can mean cloud on a lot of occasions. Though I think I get about 150-170 nights a year of clear skies. It might be more than that on average, and that means I can get lots of data to process.
I installed the base ring today. Couple of funny things. In the first image I followed the advice of Rally to screw together the base ring panels upside down. That was easy. However, try turning a 2.6m ring over on your own. It was a bit like a snake swinging about in the breeze.
The second image is the base ring sections bolted together.
Second funny thing is that whilst I spent a great deal of time ensuring the slab was level prior to the pour in the end it has a 12mm fall on it over 2.6m. That meant putting packers in on the northern side. Now I am torn between filling that gap with silicone or removing the packers and just bolting it straight down to the concrete. My builder mentality is to fill the gap and maintain the base ring being level. That way the observatory is truly level and runs properly.
I also ensured that the ring was exactly centre to a mark I put on the pier support. It is just south of the conduit. It took some time to get it right, but there is only 2 mm difference now from N/S and E/W. That is fairly critical to ensuring the dome rotates properly. The base ring has to be a circle.
I think the choice to do that was a good one Paul. Would save a great deal of headaches later if it didn't work properly, and now it's done I am sure you won't lose any sleep over it...
I think the choice to do that was a good one Paul. Would save a great deal of headaches later if it didn't work properly, and now it's done I am sure you won't lose any sleep over it...
Gotta say I am a bit peed off that the slab level was not near perfect. Something must have moved during the pour as I double checked this to make sure it was level all the way around.
In the end though it is about making sure the base ring is level.
Gotta say I am a bit peed off that the slab level was not near perfect. Something must have moved during the pour as I double checked this to make sure it was level all the way around.
In the end though it is about making sure the base ring is level.
Seriously, you are right, as long as the base ring is level it's not really an issue
Mike
LOL, did ya maka the conacrete too Mikie?
I think the problem came about because the concrete was too stiff. The MPA was a lot higher than I ordered. Done lots of driveways, shed floors and all sorts over the years, but never had to screed still concrete before. It was almost plasticine while I was screeding it. Besides 4mm per meter is not that bad. Sorry builder speak for she'll be right.
Man this has been 4 months in the making. What a good day. No wind and some high cloud about to help keep the sting out of the sun. I had some help from mates who came down to help. I could not have done it without them. I want to especially thank Peter.M for his help.
The side panels were like wrestling with an elephant (to carry them we had to turn the panels so the curve was facing up) and the door panel was like hanging onto a tigers tail while it is running. There were lots of little things to do after we got the panels up, like installing the drive rim, which we had to drill the holes for and then do up the nuts for the bolts by hand, whilst the other person had to put tension on the drive rim and bend it slowly around a circle. That was really time consuming. Then putting the drive cover which not only covers the dome drive but also holds down the dome to the base ring. Then before we could install the shutter we had to install the rollers which prevent the shutter from coming off in the wind. All time consuming and it took us nearly 7 hours all up to lock up. Very tired now but happy this is one step toward having another imaging rig working.
Some images of the various stages of assembly including one of me putting in some bolts up the top of the dome to hold the door in section in place.
It was almost plasticine while I was screeding it. Besides 4mm per meter is not that bad.
