Gina's Observatory Roll-Off-Roof Automation

[Gina]

Not ATM I'm afraid - the USB cable has been knawed through   I'll have to repair it - yet another job to add to my never ending list

[Gina]

I've made a small amount of progress on this since last posting   The south side is now equipped with 3D printed plastic wheels and brackets and running freely on the inverted aluminium angle but haven't done the north side as yet.

I have also been re-thinking the motor drive system and have come to the conclusion that a modified garage door opener would make things very much  easier.  A main problem with the winch and rope system was arranging a way to free the roof from the drive in the event of failure.  With many thousands of pounds worth of equipment securely attached to the concrete pier, to have the roof fail and stuck in the open position with heavy rain coming in is simply not on!!   So it's essential to be able to close the roof manually if the motor drive fails.  I suppose a sharp knife would be one possibility...

I have been looking into using a modified garage door opener with a bicycle chain drive as a better alternative to my earlier rope design.  I have posted about this in general in another thread but in this thread I am going into the specifics for my observatory.

Using chain drive, the whole drive system can be inside the scope room and protected form the weather when the roof is closed   Some sort of clamp system would attach the roof to the chain.  The range required is around 2300mm - well within the 2680mm range of the garage roof opener I am considering.

Apart from the rolling roof, there is a wall flap that is opened or closed and ideally, for an automated system, this should be motorised too.  However, the current arrangement is a wooden structure with shiplap cladding which is hinged to open inwards.  It is quite heavy.  In fact this has been found to be less than ideal for manual operation too - with an ever increasing weight and size of imaging rig, the space in the scope room is feeling distinctly cramped.  ATM it just clears the counterweight boom on the EQ8 mount with the rig parked to allow the roof to open.

Here's a photo of the imaging rig with the wall flap behind in the open position.

Edited December 17, 2014 by Gina

[Gina]

I think what's wanted for the end wall is a sliding "door" that is raised to connect with the roof in the closed position and slides down to open.  I also think this needs to be on the outside to keep the rain out, overlapping the fixed wall.  I am going to need to put my thinking cap on

[Gina]

The fold down flap measures 2100mm x 600mm.  I have 3 sheets of twin wall 10mm polycarbonate roofing which I got for something else but didn't use but they're only 2000mm x 610mm - too small   Just about wide enough but not long enough   Oh dear!

I'm thinking in terms of aluminium channels attached to the body of the observatory up to the tops of the walls and separate pieces attached to the roof so that they line up when the roof is closed.  Then a panel could slide up the channels and stop against the roof edge.  Like a sash window.  Also like a sash window, the panel could be raised by using cord at each end.  The two cords could be attached to a single cord that is wound up on the drum of winch.

I have some pieces of OSB and plywood left over from the obsy build so if we get any dry weather in the next couple of days I could pop out to the big shed and see what I've got.  Not going out in the rain with this cold!

Edited December 17, 2014 by Gina

[Starlight 1]

Can you make the panel a part of the roof ,like a up and over door.

[Gina]

Can you make the panel a part of the roof ,like a up and over door.

I don't think so

[Gina]

I reckon I might just be able to "lose" that 100mm that the polycarbonate is too short by   I could make a frame for the polycarbonate perhaps.

[Gina]

I shall need to go out to the obsy to check the exact design and measurements but this rough sketch shows the general arrangement of the base with the panel added in grey.  The roof and parts of the base are omitted for clarity.  The main corner posts are shown in a mahogany colour.

Edited December 17, 2014 by Gina

[Starlight 1]

Something to think about, I pick up last year one of them roller blinds to keep the Sun out that go over shop windows, ok the cover is no good but the long cylinder with the gearbox on the end

may work as a roll off roof. as you  got a warm room you can use the arms to pull the roof on and off over the warm room.

Can  leave the cover on but it will look like a citreon cv.

Edited December 17, 2014 by Starlight 1

[Starlight 1]

My one open out to a good 7ft you can ajust the arms .

Edited December 17, 2014 by Starlight 1

[Starlight 1]

The more I think about it you can fit the cylinder on top of warm room roof with the motor and rain cover over it ,and the push out bar with the arms on can fix to the open roof so you have not got to start adding pullys ect plus it help to hold the roof on as well.

PS the arms have got springs in them . if you like any photos just ask.

les

Edited December 17, 2014 by Starlight 1

[Gina]

Proper pictures will have to wait until tomorrow or whenever I can get out to the obsy and open the roof and/or wall flap but I have a few photos which I have been able to blow-up to show relevant bits.

[Gina]

I have some ideas for using the twin wall polycarbonate sheet.  I can strengthen the short edges with aluminium channels (or possibly wood).  The fixed parts on the base and the parts on the roof I plan to make from wood probably in the form of a channel up and down which the (now) window will slide.  Well, probably not slide but move on rollers/wheels to guide the window.  The roof extends well past the base framework when closed so I don't see this as too difficult.  Like the roof, the window could be guided by using V groove wheels and angle rather than wheels at right angles.

There are a couple of advantages to using the polycarbonate sheet.  It is inherently weather resistant and it will act as a window and increase the light in the scope room in daylight when the roof is closed.  One disadvantage might be increased solar heating of the scope room in summer.  The current single scope room window faces north (in the roof apex).

Edited December 17, 2014 by Gina

[Gina]

Here's a sketch showing a frame in which the window can move up and down.  These can be made from three pieces of wood for each.  2x 150mm wide and 1x 120mm wide and all 22mm thick.  OR whatever I have   The roof would have matching frames to line up when the roof is closed.

Well, that's one idea

Edited December 17, 2014 by Gina

[Gina]

For security and to prevent any possibility of the window being sucked out by storm force winds a sturdy bar could be placed across the bottom of the window opening.  Have to see if I've got any of the 75mm x 47mm timber left from the construction.

Edited December 17, 2014 by Gina

[Davey-T]

 Hi Gina, I used this to fix the end of polycarbonate sheet, this looks like plastic though, the one I used was aluminium.

Dave

 http://www.screwfix.com/p/corotherm-side-flashing-brown-x-16-x-4000mm-pack-of-2/77226

This one

http://www.ebay.co.uk/itm/Aluminium-F-Section-Glazing-Bar-for-Polycarbonate-Glass/110531112416?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D28111%26meid%3D055d13335e0b4ae88cbd26445c711158%26pid%3D100005%26prg%3D11472%26rk%3D4%26rkt%3D6%26sd%3D121514733146&rt=nc

Edited December 18, 2014 by Davey-T

[Gina]

Ah yes - thank you Dave   I'll bear it in mind but I don't think that would be suitable.

[Gina]

Forecast is better for tomorrow so I might be able to get out and take another look at the job.

[Gina]

Had a quick look but my health is still not up to doing anything much   I did open the roof and check that the additions to the eastern end to take the window will not crash into anything when the roof is opened fully.

But I will need to sort out the southern roof toggle clamp in conjunction with where the garage door opener will be put.  The obvious place for the motor drive is along the side of the top of the southern wall driving the bottom of the roof wall.  This is where I apply manual force to open and close the roof.  ATM this interferes with the roof clamp.  It is one place where the motor drive would be inside the obsy when the roof is closed and not be in the way when it is opened.

I shall get more ideas when the garage roof opener arrives after Christmas I expect.  I've ordered this one.

[Davey-T]

Hi Gina, sorry you're not feeling too chipper ATM, best have a rest and plan a few more projects did you get the all sky camera going for the Gemenids ?

Dave

[Gina]

Hi Gina, sorry you're not feeling too chipper ATM, best have a rest and plan a few more projects did you get the all sky camera going for the Gemenids ?

Dave

Thanks   No the all sky camera project is on hold.  I could do with resurrecting it.

Since this bug is stopping me from doing a lot of things I am considering postponing some astro projects and doing something else.  Feeling very frustrated

[Davey-T]

Since this bug is stopping me from doing a lot of things I am considering postponing some astro projects and doing something else.  Feeling very frustrated

Knitting ? 

Dave

[Gina]

Been there, done that, got the T shirt   Well a jumper actually rather than a T shirt plus hat, gloves, etc....

There are a couple of projects that come to mind that don't involve going outdoors - eg.  giant wall clock.  Then again I ought to spend some time clearing up the house and maybe doing some cleaning - boring...

Edited December 19, 2014 by Gina

[Davey-T]

Know the feeling, I carried the hoover downstairs this morning full of good intentions, then the Sun came out so I spent an hour looking at that, made some butternut squash soup for lunch, did a bit in the garden, cleaned a bit of the camper van, got the dinner, idled away some time on SGL and did a bit of guitar practice, never did get any hoovering done 

Dave

[Gina]

Had an unexpected early delivery this morning by Yodel - the Garage Door Opener has arrived   It was due next Monday onwards.  It's a lot bigger than I expected.    The  motor unit is about a foot long by 9" wide and 4" high    I can see I'm going to have fun working out how I can fit it