Converting my 'clamshell' obsy roof to 'slide off'

[Skipper Billy]

Following major surgery at the end of 2023 I have found it a struggle to open and close the clamshell roof - each side is ~25kgs and an awkward angle to lift especially in the middle of the night in the freezing cold. I decided to convert it to a roll off type.

There is a page on my website that follows the conversion process.  Stage 2 will be to motorise the opening and closing of the roof. Stage 3 will be to connect the motor drive system to the computer that controls the telescope and mount so I can ask the roof to open then the mount to unpark and commence an imaging run all completely autonomously and remotely from the comfort of our Lounge or anywhere in the world. When the routine has finished the scope should park and the roof should close. It will also be linked to rain, cloud and wind monitors and if any report a danger situation like rain or very strong gusts of wind the scope will park and the roof close automatically, with the option of reopening the roof and resuming the imaging run if conditions improve.  That's the theory - we will see what happens!

The page will be updates as and when progress is made (largely dictated by the weather!)

https://www.davidbanksastro.com/observatory-conversion

 

[saac]

Watching with interest Billy, good luck with the project. Your 1st build was a lovely design and very well executed - you have set a high bar, can't wait to see the end result.  

Jim 

[AKB]

Skipper,

I'm sure you've thought all this through, so I'm interested in your chosen option for the orientation of the roof, and its direction of travel. 

I assume you're keeping the apex design, and your chosen direction of travel is towards your less interesting horizon... perhaps north?  It looks like your floorplan is square, so whatever the direction, you still have a choice of the orientation of the roof ridge – is that going to be parallel or perpendicular to the direction of travel?  If parallel, then when open, you get left with the gable end on the far wall, which may obscure some of your horizon.  This seems to be the usual way of doing it, for some reason.  If, however the motion is perpendicular to the ridgeline, then you'd have the lower edge of the open roof against the far wall and the highest point of the ridge further away, so a lower useable horizon.

Perhaps it doesn't make enough difference to care about this, or perhaps there are other engineering constraints?

Just wondering.  Whatever, good luck with the process!

Tony

[Skipper Billy]

12 hours ago, AKB said:

I assume you're keeping the apex design, and your chosen direction of travel is towards your less interesting horizon... perhaps north?  It looks like your floorplan is square, so whatever the direction, you still have a choice of the orientation of the roof ridge – is that going to be parallel or perpendicular to the direction of travel?  If parallel, then when open, you get left with the gable end on the far wall, which may obscure some of your horizon.  This seems to be the usual way of doing it, for some reason.  If, however the motion is perpendicular to the ridgeline, then you'd have the lower edge of the open roof against the far wall and the highest point of the ridge further away, so a lower useable horizon.

Hi Tony

I am planning to re-use the original roof and it will stay in the same orientation ie ridge running North-South and it will slide away to the North towards the trees which block my view (they arent our trees so I cant 'adjust' them!).

The whole roof will move ie no gable remaining in place as my view to the south is pretty good and usable.  This was what dictated raising the walls 150mm as it is required for the roof to miss the scope even in its custom park postion ie weight bar parallel to the ground and scope parallel to the ground.

The apex design is a must to cope with snow loading and the orientation of the ridge was chosen to cope with strong winds - when we get really strong winds they are almost always from the west so the effect on the roof is to push it down rather than lift it and if it was 90 degrees turned round it would also put strain on the electric open/close mechnism (when its eventually fitted).

Thats the thinking - we will see what happens!

All the best

David (aka Skipper Billy)

[ollypenrice]

I have three automated sheds based here and have developed some Golden Rules, the first of which is to accept that, if a thing can go wrong, it will. For this reason we have a 'No Possible Collision' rule. No telescope can ever stop in a position in which the roof can collide with it.  (A much more lavish remote hosting provider a few miles away has exactly the same rule and he is orders of magnitude ahead of me in IT savvy.)  A design using 'rolling roof and upper sides' makes this rule easier to comply with.

Another simple thing is to make as much of the gear inside as showerproof as possible. Despite the best efforts of the IT guys who are responsible for the sheds here, unwanted openings have happened several times. Simple shower protection of fixed items can save a lot of money.

Good UPS backup is essential but not so easy to assure because office UPS machines don't like the temperature extremes of observatories and tend to have a shortish life. You probably won't have our upper temp extremes, though.

Olly

[AKB]

29 minutes ago, ollypenrice said:

For this reason we have a 'No Possible Collision' rule.

NOW you tell me … !

See my post of last night’s session:

 

[ollypenrice]

12 minutes ago, AKB said:

NOW you tell me … !

See my post of last night’s session:

 

Ouch, and if you want to do this collision thing properly (!!!) do it with a RASA...

Phew.

Olly

[Skipper Billy]

2 hours ago, ollypenrice said:

I have three automated sheds based here and have developed some Golden Rules, the first of which is to accept that, if a thing can go wrong, it will. For this reason we have a 'No Possible Collision' rule. No telescope can ever stop in a position in which the roof can collide with it.  (A much more lavish remote hosting provider a few miles away has exactly the same rule and he is orders of magnitude ahead of me in IT savvy.)  A design using 'rolling roof and upper sides' makes this rule easier to comply with.

Another simple thing is to make as much of the gear inside as showerproof as possible. Despite the best efforts of the IT guys who are responsible for the sheds here, unwanted openings have happened several times. Simple shower protection of fixed items can save a lot of money.

Good UPS backup is essential but not so easy to assure because office UPS machines don't like the temperature extremes of observatories and tend to have a shortish life. You probably won't have our upper temp extremes, though.

Thanks Olly

I did consider having the roof high enough to close it with the scope in the normal park postion, but it would create an unnaceptably high (to my Wife!) structure. Its only a 1.4m cube.

The plan is to use an Arduino to open and close the roof and it will be set up in a way that prevents the motor being activated if the scope is not in its custom park position and confirmed by magnetic sensors - it is also monitored by an IR camera and Mk1 eyeball.

The entire rig is run from 2 x 110 amp hour leisure batteries which are on constant charge - partially to provide 'clean' current, but also to stop imaging runs being interfered with as we suffer a lot of power outages. Upper temp extremes in the Highlands of Scotland are measured in single digits Celsius! 🙂 

All the best.

David

 

[LongJohn54]

@Skipper Billy  Late last year I was shown a post on Facebook where you said you would be away for a while for medical reasons and added an image of the Heart Nebula (which was a pretty big clue).

I'm guessing you spent some time in the Golden Jubilee?  I was in there in 2019 for a replacement aortic root and re-model of my aortic valve.  They had a good team then and I hope they still do.

Wishing you good health and a successful rebuild of your obsy.

[Skipper Billy]

8 hours ago, LongJohn54 said:

I'm guessing you spent some time in the Golden Jubilee?  I was in there in 2019 for a replacement aortic root and re-model of my aortic valve.  They had a good team then and I hope they still do.

Wishing you good health and a successful rebuild of your obsy.

You are very kind. I got the grand tour of Glasgows Hospitals - the heart, lung and aerobic fitness tests to see if I could stand the op were at the Vale of Leven, consultations were at the Gartnavel, MRI scans at the New Queen Elizabeth Imaging Centre, The op was at the Queen Elizabeth University Hospital and follow up at the Golden Jubilee !! The Golden Jubilee was an odd place - part Hotel and part Hospital. I have to say the standard of care I received at every stage was world class and delivered with outstanding care - even down to choosing appt. times that suited me as I had a 2 hour drive each way. I had a new Aorta and both femoral arteries - pre op I could walk about 200 metres - now I am climbing Corbetts !!

[LongJohn54]

That's quite an ordeal David.   It's great that you are in better health post-op than before.  Hopefully your strength and fitness will continue to improve.

I'd nursed an aneurysm for 50 years (first noted in Great Ormond Street as a teenager).  It had been stable at 42mm (instead of the normal 30) but then began enlarging in 2016.  By 2018 it was 52mm and in danger of going pop. At the same time the aortic valve was beeing stretched and wouldn't fully close leading to low blood pressure and feeling light headed if I stood up quickly.  All my tests were done at Stobhill or the Golden Jubilee apart from one consultation at the Queen Elizabeth University hospital.  When it comes to big operations like this the NHS is really on the top of its game.  👍

[AKB]

On 07/03/2024 at 15:13, Skipper Billy said:

it is also monitored by an IR camera and Mk1 eyeball.

Yes, I had that too… the trouble is that it’s all overseen by a Mk 0 brain!

[Skipper Billy]

18 hours ago, AKB said:

Yes, I had that too… the trouble is that it’s all overseen by a Mk 0 brain!

That's always been my problem !! 🙂 

[carastro]

Just when l was going to show your obsy off as part of my talk on Garden Observatories this month with local astro group.  (You kindly sent me photos and a video).  Your new build will not be ready in time.  

l can definitely see why you need to do it though and look forward to seeing your progress.   

Edited March 10 by carastro

[Skipper Billy]

2 hours ago, carastro said:

Just when l was going to show your obsy off as part of my talk on Garden Observatories this month with local astro group.  (You kindly sent me photos and a video).  Your new build will not be ready in time.  

Gosh, that's a blast from the past - I had forgotten I did a wee video - I have added it at the top of the conversion page for a giggle.....

https://www.davidbanksastro.com/observatory-conversion

[Skipper Billy]

A bit more progress made today. Heavy duty drawer sliders and the outer sides fitted, frame to support the roof made and fitted - internal bracing fitted to keep the roof square whilst moving - this will become important when the electric drive is fitted as only one side will be driven and it it moves from square it could jam. 

 

[Skipper Billy]

Phase 1 nearly completed - just a good bit of minor adjustment and sanding of edges and painting when its dry.

 

[Skipper Billy]

Stage 2 is complete!!!

The original clamshell manual roof is now fully converted to motorised slide off roof.

Stage 3 is to link the motor system vie ASCOM divers so i can add it into N.I.N.A. as part of an imaging riun and link it to cloud, rain and wind speed sensors to automatically park the scope and close the roof. This should be possible from anywhere in the world!! The scope position is monitored by ultrasonic sensors and an IR camera.

 

[whipdry]

I'm intrigued, can't see or imagine how you've intergrated the motors that move the roof! 

It's such a nice compact design & doesn't shout observatory when closed, seeing how well it works I'd like to build myself something just like it... any chance of having more details?

 

Peter 

[Skipper Billy]

49 minutes ago, whipdry said:

I'm intrigued, can't see or imagine how you've intergrated the motors that move the roof! 

It's such a nice compact design & doesn't shout observatory when closed, seeing how well it works I'd like to build myself something just like it... any chance of having more details?

Thanks peter.

There is a quite a bit more info (and links to parts used) on this page of my website and I am always happy to answer questions.

https://www.davidbanksastro.com/observatory-conversion

All the best

David (aka Skipper Billy)

[whipdry]

2 hours ago, Skipper Billy said:

Thanks peter.

There is a quite a bit more info (and links to parts used) on this page of my website and I am always happy to answer questions.

https://www.davidbanksastro.com/observatory-conversion

All the best

David (aka Skipper Billy)

Thanks David, I'll take a look.

Peter

[AKB]

Absolutely cracking job!

I bet you open it and close it again for fun, just to watch, even if you don’t plan on imaging.

I must follow up on your construction page to see if I can adopt your motor solution… currently manual only!

Tony

[Skipper Billy]

5 minutes ago, AKB said:

I bet you open it and close it again for fun, just to watch, even if you don’t plan on imaging.

I might !!! But I am never going to admit to it on a public forum !!! 😁

Shout out if you need help - no point in reinventing the wheel.