From Micro Obsy to Dual Pier Observatory - via Hard Work, RSI, Back Ache & Melting Credit Card!

[ArmyAirForce]

The remaining two pieces of timber were cut for the rear braces. These help to keep the vertical supports upright, especially when they have the load of the open roof on them. A steel strap joins the two timbers in the centre and is then bolted into the centre concrete foundation. The over-long runner timbers and the vertical posts were also cut down to remove the excess. The cut ends were treated with shed paint followed by several coats of waterproof PVA glue.

So that was all the roof support timbers fitted and painted and I still had time left in the day.

[andy fearn]

1 minute ago, ArmyAirForce said:

The remaining two pieces of timber were cut for the rear braces. These help to keep the vertical supports upright, especially when they have the load of the open roof on them. A steel strap joins the two timbers in the centre and is then bolted into the centre concrete foundation. The over-long runner timbers and the vertical posts were also cut down to remove the excess. The cut ends were treated with shed paint followed by several coats of waterproof PVA glue.

So that was all the roof support timbers fitted and painted and I still had time left in the day.

This build is so impressive. How are you going to open and shut the roof, Manually, or electronic.?

[ArmyAirForce]

Time for the actual runners! Two three metre lengths were laid out on the first end, with a third 'L' section of aluminium G-clamped to the rear to help keep them straight. Lots of measuring followed to try and get the runner straight and square. I ended up unscrewing the timber runner from the vertical support and adding a 1/8 inch spacer. This got the timber straight as it kinked in ever so slightly at the back of the observatory and that was throwing off the 'L' section runner. Everything was clamped up and the aluminium drilled every 300mm along the 6 metre length. Each hole was then countersink drilled followed by screwing the first runner in place along its full length.

Half was along is the join between the two three metre lengths. My "Snail Countersink" is on the right. A great little tool that doesn't chatter in the hole like traditional countersinks can. This allowed the screws to sit flush, clear of the roofs wheels.

[ArmyAirForce]

Just now, andy fearn said:

.....How are you going to open and shut the roof.....

It's going to be manual, but I've yet to decide whether I'll need a pulley to assist. The whole shed kit when delivered was 350Kg. Let's say the roof is 1/3 of the weight, I can probably pull that with just a rope. I carried out one roof end panel to give it a test roll and while there's a bit of weight behind it, it rolled quite freely up the slope to the closed position. Time will tell - possibly even tomorrow.

The inside view of the roof end. I need to add some wooden stoppers at the ends of the tracks, possibly with some spring to absorb the impact when the roof slides open.

[ArmyAirForce]

Lots more measuring followed for the runner at the other end. It wasn't easy with 6 metre long runners that are 12 feet apart. Yes, I'm mixing my measurements, but if it's OK for the Civil Aviation Authority who do altitude in feet and distance in kilometres, then I figured it was fine for my observatory! By 5pm, both sets of runners were screwed in place.

I packed up for the day and plan to start assembling the roof tomorrow all being well. The weather forecast looks kind, so fingers crossed. I'll need to add some temporary timbers to hold the end panels vertically and to stop them rolling down hill, while the rest of the roof is built around them.

[ArmyAirForce]

July 27th - Exhausted!

Just finished packing up after a 12 hour day on the observatory. Will start sorting pictures shortly, but for now, I'll just leave it here that I now have a roof that rolls!

[ArmyAirForce]

It's been a REALLY long day. Apart from the careful alignment of the runners, I knew this was going to be the most difficult part of the project. I started not long after 9am, carrying the four roof walls out to the observatory, along with some tools from the workshop.

I started at the shed end, by screwing a piece of wood to the observatory, sticking up along side where the roof wall would be. This would allow me to clamp the side to this piece of wood, keeping it still while I worked on the next section. Part number two was the rear wall. I needed a slight gap under the rear wall ( achieved with some packing pieces ), but knew there would be sanding to do.

The top and bottom rear walls were made with their edges square as it was just easiest to do it this way. However, with the roof dropping down as it rolled backwards, the two edges would bind. The lower one would need planing at an angle to accomodate the movement.

[ArmyAirForce]

After the left side and rear were screwed together, I added another temporary piece of wood on the right side to support that end while I was screwed to the rear. After that, I carefully lined up the rear of the roof with the rear wall and added a G-Clamp to the metal runner, with the clamp just touching the rear wall of the roof. This stopped the assembly from rolling down the slope and also kept it aligned. With more clamps and feeling the need to grow a few more arms, I got the front wall into place and screwed to the end walls.

At this point, I walked around the back and unfastened the clamps, allowing the roof to roll free. Of course it wouldn't roll backwards because of the square edged rear walls binding. There was enough room to roll it forwards a little way, exposing the top edge of the rear wall. Out came the wood plane and power file until the roof cleared the back edge. I was then able to roll the roof all the way back to the stops. Despite the rectangle structure being a bit flexible without the roof panels, it rolled freely without binding. All that measuring over and over yesterday paid off in getting the runners parallel!

In case you don't believe me, here's the proof! The first video of the rolling frame. It wasn't too heavy and was fairly easy to push.

[ArmyAirForce]

Looking approximately South to South South west, you can see how dropping the roof down has cleared it from my field of view for the scopes.

While standing outside, I reached over the side with my phone and held it apporximately at the height of the deep sky pier and took a picture. Even allowing for the thickness of the roof panels, it shows the roof is still below the level of the hawthorn hedge ( which still needs the park side trimming! ).

[ArmyAirForce]

Time to assemble the roof panels. Because of the size of the shed, the roof came in six pieces. The width was approximately 4 feet, with one 6 feet panel and one 2 feet panel that needed screwing together. I'm sure I saw pictures on the shed company website showing parts being assembled in a jig, but as I'd already found out when assembling the floor, that didn't guarentee square and true parts. Perhaps the jig is poorly made or the staff just don't know how to use it properly!

Each pair of roof sections were to be joined with several lengths of timber across the joint. The two outer edges with the correct distance apart, but all of the centre stiffeners were out of alignment. A combination of the powerfile and brute force with G-Clamps pulled them into alignment. The other problem was that a number of the cladding planks extended beyond the edge timbers. This prevented the panels butt jointing properly. Once again, the powerfile came to the rescue.

With a properly designed jig ( and trained staff ), these annoying errors could be eliminated. The shed itself was £1,500, which I didn't consider to be cheap and expected better, however over the years, I've found all garden structures ( play house, bike shed, etc ) to be a similar poor build quality. Being a model-maker, I'm used to sub-millimetre tollerences, not half an inch either way!

Before the first roof panel could be attached, the fron and rear walls had to be notched at an angle to allow the roof to sit low enough that its bottom edge was flush with the side wall. A chisel and powerfile were used to notch the front and rear walls for the roof timbers. I also discovered the roof panels weren't wide enough for the 12 feel span of the shed. They weren't the same width as the panels that made up the walls and I don't know whether this was because of additional wall sections that I didn't use that were designed to give the original shed the pent roof. I added two additional strips of timber between the roof panels to push the width a bit wider, but think I still need to add some more onto the outer eves ends to bring the roof flush with the end walls.

[ArmyAirForce]

Inside the roof, borrowed from another observatory build thread, I used some clasps to hold the roof down when closed. Currently I have some M10 bolts through the holes, but have ordered some carabiners to use. They have a loop in one end so they can be attached to a short cord and hang near the clasp when not attached.

On the rear wall, I added two garden gate bolts to hold the roof from sliding open. When I pull the roof closed, I can slip the bolts in to hold the roof while I close up all the clasps. I'll add some more to the front opening flap. The eves gap will be filled by more pieces of timber at some point, but I was racing the sun set today, just getting the roof fitted. I'll probably add a small mesh vent at opposite ends under the eves to allow airflow through.

[ArmyAirForce]

So almost at the end of the day's update. My elbow and hand are suffering from RSI from gripping and holding the battery drill for much of the day. All three roof panels were fitted by 9:15pm, around sun set. Here's the observatory ( bird hide! ) with the roof closed. With the weight of the roof, there's a slight sag front and rear that I have to work on, but nothing that wasn't expected over a 12 foot span.

Rear view, looking North-ish with the roof closed. The back wall is somewhat dusty still from the powerfile. I brought the vacuum cleaner out to tidy up, but by the time the roof was fitted, I was too exhausted to start cleaning.

[ArmyAirForce]

To finish the day, wifey helped me unclamp the G-Clamps from the runners and I rolled open the roof. Obviously heavier now the roof panels are fitted but not excessive. I can probably pull it closed with a rope, but a pulley or small hand winch will make the job easier.

A rear view with the roof open. I have a feeling tomorrow will be a slow day as everything is aching so much, but I'm very pleased with the progress made today. Tomorrow, I may try for the second pier adapter being fitted, then I can confirm the positions of the scopes and finalise the front hatch width.

[ArmyAirForce]

July 28th - I knew today wasn't going to be so productive, having burned myself out yesterday. I began with the vacuum cleaner, sucking up all the dust and shavings inside and outside the observatory. With a clean work area again, I proceeded to make more mess! The second concrete pier was drilled for the new adapter and the lower plate was fixed in place via studding glued into the concrete.

While that was curing, I turned my attention to the slightly sagging roof. I suspected it would sag to some degree with the weight of the roof panels and as a result, the back edge of the upper wall was now rubbing on the lower wall. if the roof was opened, it dropped a fraction below the lower wall, preventing easy shutting. I needed to fix the sag and restore the gap.

I made a plywood wedge which was hammered into the now closed up gap, to lift the wall and roof back up to where it should have been. Then one by one, I cut some diagonal braces to fit into the rear roof panel to stop the sag. Each was individually cut to fit and slightly on the large size. The ends of the timber were tapered slightly to help them fit, with some persuasion from a big hammer. The tight fitting pieces worked perfectly, lifting the sagging rear wall until the temporary wedge fell out of its own accord. The gap was restored.

I have some small brass rollers that have been kicking around the workshop for years. I think I'm going to add two to the rear wall, so that during the long periods of the roof being shut, the wall is supported. It took quite a while to fit all of the wooden braces and it was heading towards 1pm by the time I finished - lunch time!

Edited July 28, 2022 by ArmyAirForce

[ArmyAirForce]

The front wall received the same treatment. I wanted that sorted before I considered making the opening flap. While I was working out the back, I missed a Fedex delivery of the silver heat reflective bitumen paint for the roof. That will hopefully now come on Monday.

Around 3pm, I fitted the upper part of the mount adapter and the new NEQ6 Pro mount to look at the clearance between the scope and roof. It was a long walk with the heavy lump. I'm really pleased I wouldn't be carrying stuff around to set up for much longer.

Edited July 28, 2022 by ArmyAirForce

[andy fearn]

8 minutes ago, ArmyAirForce said:

July 28th - I knew today wasn't going to be so productive, having burned myself out yesterday. I began with the vacuum cleaner, sucking up all the dust and shavings inside and outside the observatory. With a clean work area again, I proceeded to make more mess! The second concrete pier was drilled for the new adapter and the lower plate was fixed in place via studding glued into the concrete.

While that was curing, I turned my attention to the slightly sagging roof. I suspected it would sag to some degree with the weight of the roof panels and as a result, the back edge of the upper wall was now rubbing on the lower wall. if the roof was opened, it dropped a fraction below the lower wall, preventing easy shutting. I needed to fix the sag and restore the gap.

I made a plywood wedge which was hammered into the now closed up gap, to lift the wall and roof back up to where it should have been. Then one by one, I cut some diagonal braces to fit into the rear roof panel to stop the sag. Each was individually cut to fit and slightly on the large size. The ends of the timber were tapered slightly to help them fit, with some persuasion from a big hammer. The tight fitting pieces worked perfectly, lifting the sagging rear wall until the temporary wedge fell out of its own accord. The gap was restored.

I have some small brass rollers that have been kicking around the workshop for years. I think I'm going to add two to the rear wall, so that during the long periods of the roof being shut, the wall is supported. It took quite a while to fit them all and was heading towards 1pm by the time I finished - lunch time!

This is so impressive.

[ArmyAirForce]

If I was checking the clearance of the deep sky scope, I might as well check the solar system scope too. So here we have both piers occupied for the first time by my Skywatcher 200PDS and Evostar 80ED, both on NEQ6 Pro mounts - and yes, the roof misses them both!

From directly behind the Evostar, you can see it has a clear view over the roof and hedge, from 9 degrees above the horizon and up. Still haven't trimmed the park side of the hawthorn!

[ArmyAirForce]

The roof was opened fully again for a shot of both scopes looking skyward. It won't be too long before they are doing it for real!

The 200PDS has a similar field of view due to its larger diameter, despite being a little further back in the observatory. While imaging a planet at 9 degrees above the horizon is never going to give a great image, it's nice that I can now see that low. At my old house, everything below 25 degrees was hidden behind the house.

There's another day gone. Not a huge step forwards today, but all essential jobs towards completion.

Edited July 28, 2022 by ArmyAirForce

[ArmyAirForce]

July 30th - I got nothing done yesterday, as I was helping wifey set up her Girl Guides camp for much of the day. Today, I was back in the workshop for much of the day. Just as well, as it has been raining on and off much of today.

The postman brought four big 10mm carabiners which have replaced the temporary 10mm bolts that were holding the roof down.

During one of the brief dry spells, I did some measuring of the roof shortfall and broke apart some of the remaining shed panels to salvage the timber to make up the gap. Several strips were glued and nailed together to fill the gap. They are over size in width and need trimming flush with the wall once the glue is dry.

[ArmyAirForce]

They were painted in bitumen paint today so that they'll be dry to trim and fit as soon as the weather allows. The felt roofing material will nail to these rails and have a cover strip added. So far, none of the cover strips for the roof or wall joins have been trimmed to length or painted.

For the rest of the day, I've been making the 12 feet long opening front flap. Lots of cutting, trimming, nailing and gluing has got the three panels joined as one. The nail holes are all filled and drying and the hinge locations marked out, waiting for the glue to fully set before I can recess the wood to fit them. I may or may not get that done tomorrow; as it depends if wifey needs help dismantling the Guide camp.

[ArmyAirForce]

July 31st - Sixteen weeks and one day into the project. Today sufferered from a few interruptions. Wifey came home first thing in the morning and dropped off our poorly daughter before running back to her Guide Camp. She went off to bed and slept on and off across the day. Between checking on her, I chiselled out seven recesses for hinges in the opening flap. After lunch, wifey came back again, with several other leaders so we could put the 4x4mtr canvas cooking tent up in the garden to dry out. All the tents got drenched overnight. All of the smaller sleeping tents are modern plastic designs and they were left at the campsite to collect tomorrow, by which time they should be dry. We'll all be going back tomorrow afternoon to pack them up.

This evening, I painted all of the eaves planks on the inside. some of these need fitting before the roofing felt can be attached. Others form cover strips over the edge of the felt once it is attached.

[ArmyAirForce]

August 1st - This morning, to help support the front panel and opening flap, I recessed two small brass wheels into the top frame, either side of the door.

I also trimmed the edge timbers that I glued the other day. Once I was happy that they were flush with the edge of the shed, they were painted in bitumen and left to dry. It didn't take long since it was a sunny morning and they were screwed in place before lunch. The infill pieces between the main roof panels were also painted in bitumen.

[ArmyAirForce]

There was a pause in work at 1pm to dismantle my wifes Guides camp tents. Thankfully all were now dry. I got back to work later in the afternoon.

Despite the diagonal bracing in the rear roof panel, it sagged a little when open and caught the back wall edge when trying to close it. I needed a method of lifting the rear roof wall as it reached the back wall.

To fix this, I added two more brass wheels to the bottom edge of the rear roof wall. An additional angled wooden support allowed the wheel to be brought to the back edge of the wall. As soon as this made contact, it would lift the panel and support it when closed.

The wheel rests on a 2mm thick aluminium strip, which extends out of the rear wall and is slightly curved downward to encourage the wheel to rise up before the wooden edge.

Edited August 1, 2022 by ArmyAirForce

[ArmyAirForce]

This close up shows the wheel sitting on the aluminium stip with the roof in the closed position.

From slightly further back, both of the new timber wheel supports can be seen.

[ArmyAirForce]

This morning, after planing an angle on the bottom of the opening flap, I took it out to the observatory for a trial fit. It did fit the hole, but was tight in a few places, shown by the arrows. To the right of the door, there was a stretch of two to three feet that would need a couple of millimeters off the main wall height, as that wasn't as flat as it should have been.

It was removed from the observatory and taken back to the workshop for the fitting of the seven hinges. This was probably going to make it a little tighter still, but I needed the hinges on so that I could mark the recess positions on the upper part of the front roof wall.

The flap was carried out once more, clamped in place and the hinge positions marked. It was then removed again so that I could chisel out the seven recesses. This took me up to about 1pm and a lunch stop. After lunch, the flap was clamped back in place and the hinges folded into their recesses, the holes pilot drilled and temporarily screwed in place with two screws per hinge.

With the flap hinged, the clamp could be removed, allowing it to swing down almost into place. It was stopped by the parts of the flap and lower wall that interfered with each other. One of the little rollers fitted the other day was removed and the top of the wall planed down by about 2mm to the right of the door.

This improved the situation, but parts of the inner edge of the flap were catching the top edge of the wall. The bottom edge of the flap had already been planed at an angle to allow for the swing, but it needed a bit more taking off with the plane, to varying degrees along its length. All of this was done balanced on a small ladder leaning up against the front of the observatory. It wasn't the easiest position or angle to plane and sand it, but I slowly got there.