SnakeyJ's Obsy Build Thread

[JamesF]

One things for certain - I shan't be laying the concrete for another any time soon.    Think I've learnt my lesson and will be buying in the grunt and concentrate on the planning and assembly in future!

Jake

I know the feeling  I've spent (more than) the last few weekends mixing, barrowing and laying a couple of tonnes of concrete (including shifting the materials from the front of the house, where they were delivered, to the rear of the house where I was using them) and lifting and relaying a load of 2'x2' concrete paving slabs at about 35kg a time (together with all the materials for bedding them on, also delivered to the front of the house).

I don't mind the hard work, but I'm useless for anything else afterwards

Fortunately I now have to bury some pipework and do other rather easier bits and pieces before I finish off the last couple of dozen slabs.

When I build my obsy, it will be on piers with a suspended floor

James

[Bizibilder]

All the hard work's over!  Looking forward to seeing the (re)build!

[SnakeyJ]

Me to Roger - I brought all the timbers home tonight so I can start re-assembling the frames.

Really looking forward to some clear dark nights to enjoy the fruits of the labour.

Looks like you are almost there with the MkII Observatory, though perhaps a few tweaks and mods to enjoy post occupation

[SnakeyJ]

Now, where did I put those instructions...

[Bizibilder]

I managed to build it without them!  !!

[SnakeyJ]

I managed to build it without them!  !!

Hopefully I can repeat the feat - reverse engineering in my case.     I've been laying out all the bits on the garage floor as a dry run, though I've still got a few important bits of the structure at the office - some still assembled in the intact front door panel.     I'll check this out tomorrow afternoon at work and bring the next delivery back with me tomorrow evening.   I also have the black folder with the CD ROM pictures on my desk as the fall back plan      I'll replace the two posts for the rail supports as I need longer ones, with my site sloping away from the observatory.   I'll also replace the runners which were sawn in half, as I think this will look neater than a repair and keep things running smoothly.   A few tubes of silicon, some spare fixings/cup washers, materials/furniture for the door and a few bits I haven't thought of yet!

It's only 5-600 screws (slight exageration) - should be finished for tea time on Saturday!!    Though I do have other duties to perform like taking the boy to Beavers and football practice....   Not holding my breath on this - it'll be finished soonish

[SnakeyJ]

Another productive day at work - we'll at least I finished a couple of jobs and sold/installed a laptop.   However, the productive bit actually refers to getting the remaining parts of the observatory loaded up.    I found my important missing bits under the pallets and now have the all important CD of assembly photos from Roger.    All setup for a weekend of bliss!

One error that has occured to me looking back over the pictures, is that the conduits I've put in under the slab for the mount cables emerge too close to the edge of the slab - looks like I shall have to get my bolster out and chisel these back to rise inside the frame once I have everything marked out.    The phrase that immediately came to mind isn't going to get past the profanity filters - but at times like this a good command of Anglo Saxon helps to express the dismay (Oh Beowulf!)

[SnakeyJ]

Managed to make some progress today, despite feeling decidedly iffy.

I cut back and capped off the three fence posts - not so easy to cut these straight once they're up.    I then got the front panel and base metal frame built and centred on the concrete base - cutting this quite fine with perhaps only 20mm margin on all sides.

I then sorted through the timbers and built the internal frame - a little trial and error here as I worked out the correct order:

A couple of glitches at this point - can you see my service ducts (there should be three rising somewhere under that frame):

The one that's just visible is the duct for my mains supply from the house - the other two are underneath the frame and run to the plinth.     As the obsy has a raised floor I can manage without these, but will probably dig down and find them just inside the frame.

Once I was happy with the location on the slab, I siliconed around underneath the metal frame and have bolted this down in three of four locations,   The fourth is proving a little stubborn, but will get their with patience and perhaps a bigger sds drill!     I'm not sure that Roger had used all these bolt downs before, as the two front vertical posts were not notched out to allow the corner brackets for the bolt down (the brackets also looked rather clean and shiny).     I had to disassemble partially to cut the notches and these were then replaced.

My next hurdle to overcome is modification to the roll off roof and retainers.   In its previous life the roof rolled back over the rear of the observatory and due to the orientation of my site I need to change this so the roof rolls forward over the door.      This will take a little re-engineering, but should be able to re-use all of the materials  and will try to retain the porch arrangement in some form to keep the water getting in around the door.     I will build the rails first and then test and adjust so that the roof locking mechanism is correctly sized/placed.

One nice result from changing the roll off is that I can re-use the roof rails that were cut in two for the trip down from Norfolk.    The joints in these will now sit neatly supported by the frame of the observatory.

Waking around with the spirit level the frame is slightly out of true leaning backwards by perhaps 35mm at the top of the rear posts.    I will pull this up and square tomorrow and I'm pretty confident that the cladding will keep this all true once fitted.

Great to see it all taking shape and hopefully I will have the cladding and roof on before the end of the weekend

[Bizibilder]

Looks familiar!  Jake the hold downs were two in the corners under the posts and two more holding the sides down about a foot from the door end.  The clips look like long "Z" shapes.  You should be able to reverse the roof easily - the only thing to move would be the front weatherboard which becomes the rear one.  Otherwise it should all be easy.  Not so sure about being 35mm "out" though  !!

[SnakeyJ]

I got all the panels on today, despite 2hrs football practice and a visit from my Danish landlord. At least most of the screwing is done and it went back together very nicely.

Also managed to drill out the last of the four anchor bolts - though had to resort to a bigger drill!

All levelled out and ready for the roof tomorrow.

I do have two lengths of metal U section left over - probably for the original sliding doors, but will check through the photos to double check.

Might even get the scope setup if tomorrow nights forecast looks reasonable - at least I can size up for the pier!

[Derick]

what is your pier?

[SnakeyJ]

Derick - I was planning to cast a concrete pier in some 8" pipe, however I've changed tack and will now go for a steel plinth with ribbed 6" pipe -will take longer as I have to source the materials, but I do know a good welder In the short term I will use the heq5 and tripod and hold off with the raised wooden floor.

Good day today and made progress - pics to follow very shortly.

[SnakeyJ]

Stormed this today, though a few mistakes along the way which I eventually worked out:

Here's the view mid afternoon:

I was feeling quite pleased with myself, but realised the error very shortly thereafter when I lifted the roof on myself - this was a struggle, but there was no one else to ask this afternoon.    Roof went up fine, but there was a rather significant gap between the walls and the rolling roof allowing me to admire Roger's engineering.    Half an hour later and some cursing over some stripped screw heads - solved with an easy out and the error was corrected!

Ignore the wonky post for the roof rail extension - this will be properly installed shortly (honest).

Just to prove it works here's one with the roof open:

Rollin', rollin', rollin'  

Here's the view from on high, taken from the bedroom window facing SSW:

Note the nice lush, well watered bowling green next door - good neighbours!

And a zoom in from the same vantage to admire the observatory in its almost completed state:

And here's the view from inside looking due North - NCP well above the roof tops from here:

LHS - E by NE  (and my next pruning/lopping jobs):

Rear - S by SE (lost this one, but good clear view).   Here's one of the internals showing the relocated locating/locking mechanism courtesy of Mr Bizibuilder):

RHS - W by SW:

Front - N by NW:

The major trade off is that I've lost E by SE to a hight of almost 60 degrees due to a tall tree.    However the views over all are better from this location and the Southern and Eastern skies will be almost unobstructed above 20 degrees.

I still have a door to make, some replacement posts for the extended roof rails and some adjustment of the roof locators/locking studs above the front door.   I will also need to see if I can modify the porch to fit in under the sliding roof - it's all quite low for me as is.    Then there's electrics and lighting to be fitted.   Still some way to go but I'm moving from build to fitting out and a few mods.

As I said in the previous post, I've decided to fabricate a steel plinth similar to Roger's original as it will fit much better with the raised floor - though I will have to make do with the heq5 tripod for a few weeks yet as I hunt out the bits and call in some favours on the welding side.

This has been a pretty straightforward and quick build, given Roger's excellent original engineering and design.    By far the biggest issues have been the clearance and preparation of the site, hampered by some very restricted access to my back garden - a long narrow side passage.    The observatory itself is bijou, but ideally suited to the corner of my garden - but looks and feels considerably better than the wobbly screwfix/yardmaster steel shed it is based on.    The roof rolls very easily and locks securely on four steel locating pins and a drop bolt.   With a locking door and small alarm unit, I'll feel very comfortable leaving the scope and mount setup - though as there's no warm room the laptop, cameras, EPs and accessories will remain inside.

Clear weather forecast for tomorrow night, so hopefully I will get my first use once I've properly fixed the rails with new posts - don't fancy tripping over one of the posts and having the roof come down on me!

[JamesF]

Looks very good.  Well done on getting it so far so quickly.

Best make two piers.  Then you can put one in that little yellow observatory too.  Might have to give the Buddleia(?) a bit of a haircut, mind.

James

[SnakeyJ]

Ah - you've spotted my warm room, the only snag is its sitting room only and choc a bloc with kids garden toys (oh and neither warm or remotely waterproof)!

The Buddleja is over due another savage prune, but I hate to do this while it is in flower as it brings so many butterflies and even the occasional dragonfly into the garden (though this may be coincidental as not sure if dragon flies actually eat in their adult stage).   I cut it back every year to about 5' and it seems what ever I do it just bounces back stronger and taller the following year - wish my fingers were half as green around the rest of the garden!

I do hanker for fixed pier in the middle of the garden for purely visual use - though I hope to get a nice 12" dob at some point so might settle for an ornamental circle of paving, or perhaps a mosaic compass rose if I get the time.    Though I might wait until after the hernia repair before lifting the spade again.

This style of build might be quite good for yourself though - the re-enforced/adapted steel shed.    I think it could easily be modified to a raised floor above a pier foundation, to avoid the major work of a concrete base.   With a little thought it can be disassembled in 3-4hrs and would move very easily on a bigger van - allowing you to keep the roof and side panels assembled.     I'm not sure what Roger's original budget for this was, but the base steels sheds are around £ 250 from screwfix.   The additional timber and fixings probably adds another £ 200, but still well under the price of materials for a traditional larch lap all timber shed.

[JamesF]

I have some vague recollection that Buddleia actually likes being pruned back hard, so in terms of getting butterflies into the garden you're probably doing the right thing there

James

[Bizibilder]

That is looking good!  It's strange to see "my" observatory in someone else's garden!!  As to cost - you are about right, I think I had some change form £450 with everything bought new and Stainless screws throughout.

I hope you can get a good roof seal at the "non-door" end now you have rearranged it to slide the other way - I'm sure you'll sort something out.  As to the door and porch - you may have trouble with clearences as the slope of the porch roof (even if very shallow) may interfere with the opening of the door.

Hope the weather clears for your "first light".

[SnakeyJ]

Thanks Roger - It really does look the biz and I'll try and put it to good use, though my first light may have to wait a few days as I haven't managed to get the gear setup tonight.   I went on an errand looking for some steel pipe and plate to make the component parts for the pier.    The plate is sorted, but the 12" and 8" pipe sections looked a little too heavy - I've got a shout out for some 5" pipe for the weekend.     Hope to cut cut the ribs, base and top plates out with my grinder and a few disks - then file the edges down.    But if it looks a little too tough I can borrow a plasma cutter for a few hours on Saturday morning.   With luck I can get this welded up next week and then prime/paint over 4-5 nights.

I got the new posts (rail supports) in and painted today, so everything is a bit more safe and looks much better.

The rear of the obsy looks pretty good 'n tight weatherwise, though I need to drop the receivers for the front locking pins 1/4" and need to sharpen a chisel for the rebates.    I'm sure I'll have a few leaks to contend with, but the location is quite sheltered - I'll have to wait for the rain before I can get a good idea on this

Distracted by the kids this afternoon, so the photos will have to wait until tomorrow

[SnakeyJ]

Photo update to show the new rail support posts installed and painted.   

All properly postcreted in place - though I the weather board is catching slightly on the horizontal brace.    Rather than drop it 1/4", I think I will probably fix it between the end of the rails as brace come end of travel stop.    This will give me a little extra head clearance, provided that the rails are stiff enough not to bow out and allow the roof to drop.    Alternatively I may regrade the slope so that my step up comes just after the line of the posts/brace.

Hope to get the door made this w/end and trial fit prior to removing for painting indoors as the forecast is looking a little iffy.    Once the door's fitted I'll concentrate on the wiring and manufacture of the pier.

On the plus side my garage/utility room has now been repaired so I'm hopeful I can reclaim my lathe from it's long excile in the brother in laws garage - this should allow me to turn up my own pier adaptor for the HEQ5.

[SnakeyJ]

After some reflection I think I will re-grade the path so that I step up after the posts and spreader!

Also just dropped a drawing and BOM for the pier in with a local fabricators for a quote.    The Steel Erector I was going to source the materials from has gone to the wall, so I may go the hole hog and get the fabricators to cut and build, or let them cut and supply a kit of parts for welding.

[SnakeyJ]

After some time chasing local fabricators and steel suppliers, that all seem to have closed shop recently - I finally got some pricing back from a company about 1/2 mile from where I work £ 188 built (inclusive of VAT).    Given that this is cheaper than the Skywatcher pillar mount, I've bitten their hand off and expect delivery by end of next week.

The design is based on Roger's original pier built for this observatory (picture below):

I've modified this slightly to allow for locally available materials.    The pier will be constructed of mild steel, from the following components:

Base Plate, 1 of 300 x 300 x 10mm

Column, 1 of 150 dia x 1000 x 8mm

Ribs, 4 of 60 x 500 x 10mm

Top Plates, 2 of 750 x 750 x 10mm (one will be supported by M12 threaded bar/bolts to provide hight/level adjustment).

I think this may be slightly over specified and would probably support many tons balanced load, though provided I can shift it in without sustaining further injury I think big is beautiful.    The pier will be left hollow with a hole in the top, which will leave me the option of running cables through it and filling with dry sand if needed to deaden any vibration.

My pier foundation is 16" square and I got a fair float finish on this when cast - but thinking I may pour some self levelling compound on this to get a really good even contact between the pier and foundation - comments or alternative suggestions welcomed.

As I didn't cast pier fastenings in to the foundation, I am planning to fix with M14 x 300mm threaded bar - this will be sunk in resin filled over size holes.   Fortunately work can provide some decent drilling equipment and the resin is a structural support grade product supplied by our local diamond drillers TST Ltd (Clever devils who have developed a reverse taper boring/fastening anchor solution stronger than the titanium bolts they use).    I shan't be using Titanium myself as it might cost rather more than the mount, I'll probably stick with the Zinc plated, or possibly stainless - though SS is possibly more prone to shear if over tightened.

The structure is standing up really well, with no discernable leaks despite some very heavy rain over the last 48hrs.    Should fit and paint the door this weekend, and then then just the lighting and electrics to wire in!     What chance of the weather clearing for next weekend to allow me to get some first light?

[dmahon]

My pier foundation is 16" square and I got a fair float finish on this when cast - but thinking I may pour some self levelling compound on this to get a really good even contact between the pier and foundation - comments or alternative suggestions welcomed.

Alternative suggestion is an angle grinder and a concrete grinding disk.

[SnakeyJ]

Alternative suggestion is an angle grinder and a concrete grinding disk.

Thanks for this - strangely I've never seen one of those before, though the base is actually pretty good (level and fair) - though this has given me an idea and I might just go over it with a big belt sander to remove any high points, and probably won't need any compound.

[SnakeyJ]

Insufficient materials (Gravel board) to make the door so stripped out the frame for the concrete base and did a little landscaping.   I now have the path in the correct place and have cut away the bank to allow a step down before the brace on the roof run offs.   I've even grass seeded all around the path - though this may be a bit of a job with my mower, but will hopefully stop the neighbours cats using the soil as a latrine!

May get the scope setup tomorrow on the tripod as the weatherman is promising some clear sky - at least it should give me a first trial!

[wxsatuser]

Looks real smart Jake.....hard work about to pay off.