Observatory Construction

Pre Construction - 28 October 2002

Here you can see the base frame of the shed laid out on the grass.  Once the plants have been removed and a based laid, the frame will go in hard up against the fence.

The only trouble with this setup is that the camera USB connector will not reach the house so the observatory will have it's own computer that I can connect to at 100mb/sec using a Cat 5 LAN cable and VNC software.

Preparation - 02 November 2002

Here I have cleared the garden to make way for the shed but I have saved some of the plants for replanting elsewhere.  It took several hours to dig up the plants then to re-pot them as well as ripping out the vine.

After lots of advice form the Robotic Observatory list, I have decided this shed will have cement footings for the shed itself, cement blocks laid for the tripod feet and a wooden deck/floor decoupled from the tripod.

The Walls are up - 24 November 2002

One wouldn't think that putting up a metal kit shed would take this long but I have been winging it - designing the shed on the fly in my head as things progress.

Here some of the internal framing is up and the shed stands rock solid without it's roof.  Though not a big shed, the wind made putting the walls up quite difficult - not to mention the bees in the bottlebrushes on either side of the shed.

Backyard View - 24 November 2002

I wasn't joking when I said I had a small backyard - here it is in it's entirety.  Once the shed it up I will add decking under the verandah pave a path from there to the observatory.  

With luck the roof runoff rails will be a fold up affair so I can leave it down during the day.  I'll be using 40mm aluminium angle as tracks and braces for the roof.  I'll also be relying on this angle to keep the wooden rails straight.  It won't be enough to prevent warping but it should stop the wooden track supports bowing.

Roof Skeleton, Door and Framing - 15 December 2002

Roof frame, Wall frames, door and track are all completed.  The 35º C weather hasn't been helping, particularly with a tin shed.

The roof run is relatively smooth but I have yet to apply grease to the 'runners'.  The grease will also act as a 'seal' to the outside elements and as a bug barrier.  The door hinge is very inadequate and it will need some modification.  There are studs attached to the framing either side of the door.

You can see from the state of the grass what the drought has done to us but at least it looks like we might be starting to get clear skies.

Track detail - 15 December 2002

Here you can see the track on one side.  2 Aluminium Angles are used as tracks.  3 synthetic wheels (40kg capacity each) are screwed in each side.

Additional tracks will extend out the front of the shed but will actually fold up and down.  Suitable bracing and backing have been attached to the shed so now all I need to do is find some decent hinges.

Without the sheeting the roof is really quite light.  I'll be using a set of 4 turnbuckles to keep the roof attached to the shed when not in use.

Roll Off Rails - 22 December 2002

Completed the roll off rail area.  It folds down but is too long to fold flat with the wall.  Not too sure the fold down option is a good idea.  Once I get the shed back into position and painted I will consider whether to persevere with the concept or make it a permanent fixture.  

With temporary uprights the roof rolled off well enough so the alignment worked out OK.

Corner Detail - 22 December 2002

To make sure the roof doesn't blow off I have used 4 turnbuckles to hold it down. 

Roof done and a coat of paint - 23 December 2002

Well a cold change came through last night so it was full speed ahead.  Got the roof panelled and locked down then got out the Dulux Weathershield and Wattyl Solarguard and started painting.  2 Coats is not enough (finished looked pretty rough) but a third coat should do the trick.  Weather permitting that should be tomorrow.  Once applied and dried I will move the shed back into position and bolt it down.

Once in it's final position I will erect the runoff uprights and see how they are placed.  If all looks OK (and my wife agrees) I will rig the runoff permanently.  It is certainly tall enough to no get in the way.

Almost finished (Roof Closed) - 24 December 2002

Shed is now back in position with walls painted.  Here you see the set-up with temporary runoff supports roof in the closed position.  Turnbuckles take less than a minute to loosen and re-tighten.

Almost finished (Roof Open)- 24 December 2002

Roof in the open position.  A stiffish slide but some grease over the aluminium angle will improve this as well as providing a good seal.  Back and sides of the roof are sealed - now just need to work on the front.

As a finishing touch I will need some external architrave to screw into the top outside of the walls to 'seal' the top of the sheeting.  The floor will follow once the shed is 'waterproofed' and then the door will be strengthened or replaced before I set the scope up.

Finished - 30 December 2002

Well the observatory is complete.  It has taken a little more effort than I first imagined but I think that's just the hot weather talking.  The scope was set up inside the shed as a trial run to test tripod height and roof clearance.  The final height gives me minimum clear altitudes of:

33º South
26º North
19º East and West

This is considerably better than I had first thought.  I had thought my limits would be 45º North and South and 30º East and West.  

Still some internal work to do for fittings and fixtures.  The tripod feet 'cleats' work well to stop any movement of the tripod (accidental bumps won't move it - just causes vibration that takes a while to disappear.).  Still plenty of room in the shed.  I will construct a temporary fold down desk just to the right of the front door so that I can sit next to the scope to do the initial field testing of the electronic/control setup.  On pleasant evenings it might even be nice sitting out there as well.

I have prepared more detail in a  PowerPoint presentation - You can access it here (387kb).  Total cost of the observatory was under $900 AU ($450 US) not including any fixtures or fittings.

Solution

Well I have now isolated the tripod from the shed.  3 holes were cut into the floor to allow the tripod to extend through and sit on pavers on the ground.  I'll just have to put up with the creepy crawlies that come through - but I will be laying a lot of insect surface spray.  Now just waiting for a second clear night to see how the change affects things.

First Light - 01 January 2003

Well after 2 days of rain, the shed got a good test.  No leaks as such but do have some splashback around the door.  Just need to find where the water is seeping from.

First light - I was excited.  The observatory provided some shelter from the wind but not as much as I had hoped.  I then attempted polar alignment and this is where the problems started.  My weight on the the floor - shifting my weight to be exact - was enough to cause the field to shift 10 arcminutes.  This made alignment impossible.  In any case I got close and decided to continue - after all - I haven't been getting too many clear nights lately.

I stayed off the shed floor and leaned in to set the computer.  To my horror I found that guiding failed as well - why?  My body leaning on the shed wall was enough to move the guide star 20 arcseconds.  Well I leaned and balanced and didn't touch a thing and managed to do some follow-up observations of several MP's.  I had to leave the door open which probably didn't help the wind situation.