Observatory Planning/Build - Seeking my 6 year old's planning permission!

[ArmyAirForce]

I could barely pull the trolley loaded up with 300Kg of ballast and cement, and thought I was going to have a heart attack getting it back to the car, and then unloaded and into the back garden. After a quick bite to eat, concrete mixing begnd the hole slowly started to fill. Once up to the bottom of the tube, it was left for a little while before the pier concrete was mixed.

Some of the hardcore from the hole had been added over the top of the concrete to add a bit of weight around the pier base to prevent the concrete slumping from the weight of the pier concrete. It was mixed, and pour in bit at a time, followed by packing it down with a piece of one and a half by one timber as further layers were added. Once at the top, the pier bottom plate was refitted and bolted up, to hold the bolts and re-bars in alignment while the concrete cured. When that's done, all the jigging wood can be removed. 

So after six and a half hours work, the job was done, my hands were sore, my back hurt, but I have a pier!

[ArmyAirForce]

Monday 7th - All the jigging timber was removed on Monday, and the area above the concrete block was levelled ready for the paving. Once moderately level, the patio weed barrier was folded back into place and the sand bed was re-laid, followed by the paving slabs. Of the four that were lifted, one was used in a different corner of the patio, to replace a cracked one. That left three good ones which would fit around the pier without cutting, and I then concreted the last square around the pier. The family initialled and dated the concrete, followed by a cookie cutter star shape.

I'll be using more decking planks for the obsy floor, suspended a little way above the paving. Before the floor is laid, I'll be cleaning up the pier tube. 

[ArmyAirForce]

Late in the day, I tried my NEQ6 and 8 inch tube rings on the pier to check clearance. It was lower than the roof, and in fact, probably could be an inch higher, but certainly enough clearance for the roof and roof support structure. I could actually make some large thick washers that would lift the top pier plate a bit higher if needed, to give a little more height for my West view, but it's not really important right now. The most important part is that the tube rings miss the roof!

A while later, I brought my Evo 80ED down and fitted that to the NEQ6. The mount wasn't powered, but with the solar filter fitted, I manually pointed it towards the Sun and shot a few RAW shots and video. So there it is, first light ( and a big bright one it was too ), and the obsy doesn't even have walls yet!

[ArmyAirForce]

I have some structure now on the observatory. I had to cut one of the roof supports as it lined up with one of the vertical bars in the fencing. I'll add some doublers either side of the bar, to re-attach the support between the fence and the workshop wall. The front roof support just needed a vertical slot cutting in it to clear the fencing, but this will also have some doublers glued and screwed in place to strengthen the area cut to clear the fence. The Aluminium channel that the roof will run in screws on top of the timber and is clear of the railings. 

After a little more work on the structure for the small door within the larger door on the front ( shown dotted ), I'll be ready for a moisture barrier and cladding. Then the roof. It's coming together faster than I expected.

[ArmyAirForce]

What was planned as a quick shopping trip this morning, turned out to be a visit to three stores and took until lunch time. I went to the local B&Q first, as it is only a quarter mile from home. I got all the small bits of hardware I was after, grabbed a sheet of 6mm ply and heading to the cutting facility. The saw hadn't been used that day, and so the operator had to do the safety checks. The saw failed; and couldn't be repaired without parts. Hmmm; slightly annoyed, then the last thing on my list was the moisture barrier and it was out of stock in my local store and the surrounding stores. 

I took my purchases home, switched on the laptop and checked Wickes to see if they stocked anything similar. It turns out they stocked the same item, just packaged under their own brand. So I set off for Wickes and bought a roll, but they don't have a  wood cutting facility, so I then had to continue to Sunderland's B&Q for the plywood. I got back and had a quick lunch and got to work on the moisture barrier.

These two pictures show the storage area at the back right of the observatory.

[ArmyAirForce]

Fortunately, I didn't have any school runs to do today, so I got an un-interrupted afternoon. The ply was cut, glued and screwed to the door frames ( except the small door ). This was to stiffen the structure to help it keep its shape when open. The top edges still need trimming flush with the roof supports. The ply was given a couple of coats of dilute waterproof PVA glue to protect the wood, but will eventually have the moisture barrier and cladding.

Even with just the moisture barrier stapled in place, when standing in the observatory, it was noticeably warmer and less windy. Several of the cladding planks were pre-painted with a couple of coats of play house green, as the space between the obsy side and patio wall is quite tight on space. They will have further coats, but at least if I miss a bit, it will already have a couple of layers of paint to protect it.

[ArmyAirForce]

After a trip to Metal Supermarkets to order the roof runners, I got back to cladding the rear of the observatory. When that was done, I finished the side facing the workshop, and then started on the front. The large door was cut free from the structure to attach the moisture barrier and then screwed back in place for the cladding. Feel like I'm getting somewhere now, and it's only a week after pouring the concrete.

[The Head Gardener]

What a fantastic project   and a great record of each stage of the build.  Look forward to seeing future updates.  At some distant point in the future there is a chance of a small obsy in our front garden; for now I content myself with 'research' a.k.a. having a good nosy at what others achieve.

Jayne

Edited March 13, 2016 by The Head Gardener
Added signature

[ArmyAirForce]

10 hours ago, The Head Gardener said:

What a fantastic project ......

Jayne

Thank you.

Today was another busy day. While the space in the observatory was fine for my Evo 80ED, it proved to be a little too tight for my 200PDS at one particular angle. When pointing a few degrees above the horizon, low in the East, the mirror end of the OTA interfered with the roof runner support. I know low in the East isn't the best place for a good image, but I do like a Moon rise, so had to make some changes. I built anothert box on the side, which started about 20 inches above the ground to clear the brick wall that supports the metal railings. I think perhaps I worked out the scope and pier position without allowing for the weight of the DSLR, which moves the scope on the mount to maintain balance. Anyway, all sorted now!

[ArmyAirForce]

I also got the main door fully cladded and painted, along with the pillar to the right of the door. Four large hinges support the weight of the door when open. Late in the day, I tried the 200PDS back on the mount. 

[ArmyAirForce]

By 18:00 hrs, the Moon had appeared from the hazy sky, and although still surrounded by haze, I shot a two and a half minute video with my Nikon D3200. It was taken on the 200PDS, but the mount was unpowered, with the moon just drifting across the sensor. 923 frames stacked out of 3700 frames taken. Typical, hazy sky and excellent seeing! As the Moon got lower later in the evening, the haze built up, otherwise I might have had a go for Jupiter.

[ArmyAirForce]

Yesterday, I made the small door. I built the frame in the hole of the big door, with small spacers to give clearance, and once glued and screwed, screwed on some diagonal timber to hold it square so it could be removed. Six cladding sheets were cut slightly over size, and glued into a sheet. This was then glued and nailed onto the frame. Once dry, it was hinged, the hinges then removed for painting before refitting. I'll probably paint the large door hinges to match the green timber.

[ArmyAirForce]

While working on the door, I was also cutting, painting and fitting the roof support timbers to the workshop end wall. Tomorrow I should be picking up the aluminium U channel for the runners.

I tried some solar imaging around mid day, with the mount powered up for the first time on the pier. Seeing was poor, and the results weren't great. Late in the afternoon, the Moon was in and out of a thin layer of patchy cloud, but I had another go, and seeing had greatly improved. I took a DSLR video against the blue sky, then fitted the ASI120MM for some higher resolution videos. All turned out well. There was a little cool breeze, but the walls sheltered me and the scope well. The brightness of the videos was up and down a bit, but the 742nm IR Pass filter helped get the best of the seeing.

I want to build a collapsible table for the laptop, fastened to one of the walls, but before I do, I'm going to play with different positions for the laptop with targets at different points in the sky, and see where works best, or whether I need two tables for different parts of the sky. When doing planets, I need to be in reach of the filter wheel and to be able to reach the focusser to change barlows etc.

[ArmyAirForce]

Most of today was spend making the hinges for the split roof. They were cut from 5mm aluminuim sheet. The only other thing done was to cut four 8 inch wide strips of 5mm ply wood, which will form the sides of the roof panels. I balanced these on the roof supports in the open position, to estimate whether they would interfere with the view. It appears that the upright sides of the inverted roof section when in the open position, will be below the house roof height when viewed from the telescope.

[ArmyAirForce]

Work began on the roof with the lower and more substantial section. This was trial fitted on the roof to work out the size of the upper section and to check my reach to pull it closed again. After a few days on order, my aluminium channel runners arrived. Two sections about 10 feet each of 50mm channel. Holes big enough for the screws were drilled from top to bottom, and then the upper hole was enlarged to get a screw driver through and the drill was also lowered enough to countersink the smaller lower holes.

The channel on the door side was cut into a small 6 inch section for the fixed pillar to the right of the door, and a longer section for the main door. They were all clamped to the other channel to keep them straight while they were fitted in place.

[ArmyAirForce]

A little later, I had the four wheels fitted to the lower roof and went for a test slide! Ths shot caught the roof mid roll, which was smooth down to the clunk where it hit my workshop fascia. I have two coil springs which I will fit at some point to stop and cushion the roof at the lower end of its travel.

With that test done, the lower roof frame was completed and the 1/2 inch ply top was glued and nailed into place. I then began framing up the upper roof sides.

[ArmyAirForce]

This morning, I had another test fit of both roof sections, before returning them to the workshop. They were tried in both the closed and open positions, although the hinges are not yet fitted. 

[ArmyAirForce]

It gave me a chance to check the view, and by holding a camera roughly in the position of the scope either side of the pier, I got these two shots which suggest the framework doesn't extend above the roof line.

[ArmyAirForce]

The roof panels were clad next, and last thing tonight, I got the cotton waterproof layer applied with several coats of dilute waterproof PVA. Once dry, and after a couple of other odds and ends that need doing, they can have their gloss grey top coats painted.

[ArmyAirForce]

The roof panels had dried overnight, so the excess fabric was trimmed off and the hinges positioned, drilled and fitted.

[Physopto]

Hi ArmyAirForce

Just as an idea, probably far too late. Why not fold the upper section onto the Wendy house roof instead. May be easier to fold up and down. Also if you seal the edge as a hinge it will be a bit more rain proof. Then there is only one section to run on the aluminium runners.

Nice build by the way.

Derek

Edited March 20, 2016 by Physopto

[ArmyAirForce]

Two strips were added to the roof joint, one on each roof section. On the lower roof, there's a raised lip, while on the upper section, there's a raised lip with an over-hanging piece that fits over the lip on the lower roof when they are closed. This should keep most of the rain out, but below that, between the flat ends of the roof panels will be a rubber cord seal that will be pinched when the panels are closed.

While that was drying, the roof was added to the storage area of the obsy, using some left over cladding planks. Like the main roof panels, these will be covered with fabric applied with waterproof PVA, before gloss tops coats.

Last thing this afternoon was to gloss coat the two main roof sections.

[ArmyAirForce]

1 minute ago, Physopto said:

Hi ArmyAirForce

.....Why not fold the upper section onto the Wendy house roof instead......

Derek

That was suggested early on by a club mate, but it would block too much of my North view. As it is now, I don't loose any view from the roof when open.

[The Head Gardener]

Looking good, are you weather-proof yet?

Jayne

[Physopto]

I'm sure he is but maybe not the Observatory