Looking at this , sick of lumping about and polar aligning my scope , was bad enough when I was using the 10" newt on my old CG5 on a steel tripod, but the Atlux is easily 3 or 4 times heavier than the old GEM (looking at head, with no counterweights only).
So , to preserve my back and avoid straining something, and make my time at the scope more productive I'm seriously looking at a garden shed that I will have modded so roof can be rolled off so I can set up the scope on the new GEM and also my old GEM on separate "permanent" pedestals all "under one roof.
I was considering putting my roll off roof observing shed right next to my garage (with a roll off skillion style roof and the north wall of the garage forming one wall of my shed , and having my piers footing below decklevel with my piers protruding through the deck ,with a deck built around the piers and above the ground as my floor (level with the top of my garage slab) but it looks like a suitable timber deck (3mx3m in this case) will be prohibitively expective (way outside what I am prepared to spend).
I may return to this but with a concrete slab rather than a above ground deck but I will loose a big bit of the low southern sky with this arrangement while gaining some more low north and west sky .... gain some loose some .... oh for a flat horizon or being on the top of a hill somewhere....
So I have reconcidered , and am now looking at a using a concrete slab as my base despite concretes poor thermal properties.
Situation
I have a very poor northern sky (high horizon, obscurred by the neighbour's garage somewhat, and badly light polluted (that's the general direct of Charlestown Square (if you live in Newcastle you know that place is lit up permanently like a Xmas tree)), my southern and Eastern sky are not too bad (considering I am in basin surrounded by hills) , and my house obscurs much of the western sky (but blocks a street light pretty much right infront of my house).
My lard slopes downhill from w --> e ( there's a 12" drop over 6m at my garage which typifies my back yard.
So I have little choice but to orientate my shed eastwest (long axis) and I am considering a 3.8mx2.4m shed at least or maybe a 3.8mx3.3m shed (depends on concreting costs , most likely choice due to space limitations in the yard is the smaller one).
I think I'll arrange the roof to roll off to the north (will need to be modded to effect this by adding a horizontal cross rafter at each gable end (see sheds c/- h0ughty ... thanks mate for finding that ....) rather than to the east which is the other possible direction but will require more materials.
I am hoping the total cost of my shed will not go much over $1000 including slab .
Those who gone down this path already ,
a) do you think these shed sizes are adequate or too cramped for two setups (one with a wideange sky patrol type camera platform based on the old CG5, one with the 10" f4.6 newt on the Altux) ?
b) has anyone bothered arranging their roll off roof shed so the SCP is always above the southern wall of their shed (once properly polar aligned you never need to see it again , though comets low in the southern sky sometimes come along and they may be lower than the SCP) .... thoughts anyone on this ?
c) parking the scope when not in use , how far is considered a minimum desireable clearance so the roof clears the mount and tube and what ever is on the tube safely when the roof is rolled back on , or off ?
ie my OTA has an OD of 316mm, so when parked horizontal , is a clearance from the tube centreline of 200mm adequate ?
(assuming nothing on the tube will project above top of the tube in this orientation .... ....Probably a dum question but it will govern the max height of the pier the Atlux will live on assuming I keep a big part of my low southern sky below the SCP.)
All this assumes the gable roof sheds I am looking have roofs that are light and I convince the company who makes these to make roof so it can be constructed as a separate module (that is reasonably rigid structurally ) from the shed and can be simply lifted onto the rails when these are ready. (C H E A P L Y ! !)
Last edited by Ian Robinson; 12-11-2008 at 10:14 AM.
Answers:
a) Bigger the better. I've got an 12" LX200 on a reduced height HD tripod in an 8' x 6' tine shed. Fits, but an extra couple of feet all round would be nice!
b) Doesn't matter; once you've set up; who cares!
c) The roof on mine just clears the 12" with a set of 120mm guide rings/ ED80 on top, when horizontal. Angles of dangles and limited horizons.....
expensive ??? about $120 all up from a timber merchant (wholesaler) in hardwood not the big green (B's)
about 4 hours work to build
Well based on a quote my mum got to build an elevated one out the back of house (hers was 6mx3m and was to be 6 ft of the ground at the house wall (oooo .... handrails handrails needed) and was to incorporate her existing back stairs), she was told at least $10k so it wont happen.
So I presumed a 3mx3m would be maybe 3/4 this .... it's mostly labour .... but based on your response - 'I'll head to Mitre10 at Warners Bay (bugger Bunnings - I actually want someone to give some service) and I'll now make serious enquiries on that total for materials costs , then I'll chase up a local handyman (I don't have a lot of carpentry power tools , just a jigsaw and handheld circular saw) for a price to construct it ....so might go that way yet.
Last edited by Ian Robinson; 12-11-2008 at 10:17 AM.
You only need your deck to be on low stumps which is an easy setup compared to 6' up! If you do it yourself then its relaively as cheap as chips compared to the scope setup and the rest of the observatory.
Well based on a quote my mum got to build an elevated one out the back of house (hers was 6mx3m and was to be 6 ft of the ground at the house wall (oooo .... handrails handrails needed) and was to incorporate her existing back stairs), she was told at least $10k so it wont happen.
So I presumed a 3mx3m would be maybe 3/4 this .... it's mostly labour .... but based on your response - 'I'll head to Mitre10 at Warners Bay (bugger Bunnings - I actually want someone to give some service) and I'll now make serious enquiries on that total for materials costs , then I'll chase up a local handyman (I don't have a lot of carpentry power tools , just a jigsaw and handheld circular saw) for a price to construct it ....so might go that way yet.
You don't need much else to put it together Ian. Get a decent handsaw, Battery Drill and screwdriver bits, a hammer and a tape measure and your away.
You only need your deck to be on low stumps which is an easy setup compared to 6' up! If you do it yourself then its relaively as cheap as chips compared to the scope setup and the rest of the observatory.
Sounds like trip to Bunnings and Mitre10 may be in order tomorrow to talk with them about cost of materials for the off-ground deck for option A.
Still waiting on the concreter to quote the slab for option B.
Anyone have any experience with this stuff http://www.apsversiclad.com.au/pdf/brochure.pdf
Their Spacemaker 1000 insulated steel roofing looks like a great option .
Their Spacemaker modular wall panels look very interesting too (even better , they are also insulated).
==> option C ??
Last edited by Ian Robinson; 12-11-2008 at 10:25 PM.
I am looking at installing a free standing shed with a roll off roof. This will permanently how two telescopes on permanent piers.
the size and arrangement is shown in the attachment.
The shed I am interested in will be 3.78m long x 2.34 wide with wall panels 2.13m high. I would prefer each wall except the "front" wall to uninterrupted (no windows), the front wall will only have a door (sliding is preferred).
The two end walls will support timber rails that the roof will roof off along.
There is no need to make provision for AC power - everything will be powered from 12V batteries .
The roof I require is a low pitch gable roof and I would like it supplied prefabricated if that is practical and it is light enough.
The materials I like are ;
walls = 38mm think metal clad PANELINK
roof = SPACEMAKER 1000 + what ever structurals is needed.
Q1 ; how heavy will a pref gable roof (400mm pitch) be ? how much to prefabricate it ?
Q2 ; how much to manufacture the 4 walls required + structurals ? How heavy will each wall be ?
Q3 ; how long from order placed to supply ?
Thanks ian Robinson
]Response : Hi Ian
]I have attached a price list and specs sheets to help you with your enquiry – we only manufacture the panels you would have to contact a builder to help you with the installation and what panels and extrusions would be required, the turnaround time from order to supply is normally around 4-5 working days for wall panels and 7 working days for roof panels. Spacemaker 1000 roof is aprox 8kg per sq meter and panelink panels are aprox 4kg per sq meter.
Hope this information helps – if you have any further queries please do not hesitate to contact us.
Regards,Rhonda Mort
APS VERSICLAD Pty Ltd
They provided attachments including a detailed price list (too big to attach ... if anyone wants it .... email me and I'll share it).
Costing estimate base on info provided to me for Option C
A prefab gable roof ??
Spacemaker 1000 roof sheets 50mm thick (uninsulated steel roof sheetiing gets hot and reradiates significant heat , these are insulated .... this will keep the telescopes and slab cooler in summer a definite plus I think , the sheets are also very strong - you can walk on them up to 4m span !!! - so if the apex is strongly joined together , minimum structural reinforcement is required ?) are $86 per linear m , they are 1 m wide.
A few calcs reveals the prefab Spacemaker 1000 (2.4m x 3.8m x 0.2m pitch) roof will weight in at 74kg if a pitch of 400mm is used and sheeting works at about $800 (making queries on cost for a prefab roof (might be another $100 say for assembly of the pref unit ??).
Using standard Panellink panels (2.4m x 1.2m) the above will produce a roof with 100mm over hang on each end (enough for the external rails ??).
At 75kg it's a 2 man (probably a 4 man job lifting a pref roof this size to the rails about 2.2m off the ground unless I get cleavour , I'm not a gingerbeer for nuffen !)
Easiest end pieces are marine plywood I think both cut from one sheet.
The insulated walls the bee's knees option .
$70 / lin m (comes as blanks 1.2m x 2.4m x 36mm thick (?)) for plain (Zn coated steel on both sides (also insulated).
I figure 9 standard sheets (cut) with (provision for a 1.2m wide entry door) are needed if I go for a shed 3.6m x 2.4m makes it easier). (If 9 sheets are needed = 24 lineal m = about $1700 for walls panels (uninstalled) made from basic Panellink panels .... a tad pricey but would be very nice.
Poor mans walls option : construct walls like a panel fence or simply build a timber or steel framed wall and Hardyplank it. Food for thought (visit to Mitre 10 or Bunnings worthwhile).
Door
Maybe a slider or hinged entry door made from a varnished or painted marine plywood sheet (1" thick) will suffice.
Thoughts anyone ?
Last edited by Ian Robinson; 13-11-2008 at 04:28 PM.
Ian. The single biggest influence on my imaging was megadata, what ever you do, try to allow roof closeing in any scope orientation, so that you can fit a simple motor/rope/timer close in the future, to allow imaging long after youve gone to bed.
Ian. The single biggest influence on my imaging was megadata, what ever you do, try to allow roof closeing in any scope orientation, so that you can fit a simple motor/rope/timer close in the future, to allow imaging long after youve gone to bed.
I remember your discussion of how you built your observing shed .... I must admit, I'm moving in a similar direction.
Bassnut's observatory link http://fredsastro.googlepages.com/observatory.
Your off-the-ground platform floor idea inspired my Option B (shed butted up against my garage). Sloping back yards are a bummer.
Good engineers aren't scared of using other people's ideas if they are good ideas.
I'm still waiting for the concreter who subs for the sheds place in Cardiff to do a quote for my slab .... he's pretty reliable (not) by the looks of it. Think I'll try someone else for a concrete slab quote. Memories of my experiences when I had the double garage built ..... concreter turned up, dug about a bit and disappeared for 4 months and was always coming back next week , wound up sacking him and getting someone else and told him he could kiss goodbye any payment from me for the work he'd done .... I never paid him.
Yet to visit the sheds place too.
Anyone in Newcastle area know of a good , cheap , reliable concreter ?
Last edited by Ian Robinson; 13-11-2008 at 08:36 PM.
Why not do the concrete pier yourself?, its not hard. Really, rio is not required.
That's something I am definitely concidering , I need two .
I'm concidering using an offcut of PVC water pipe (I happen to have in the rafters) which is about 8" OD as the mould , and using quickset cement mix (if I can it with fine gravel in it) and dumping the dry cement mix into the pipe buy the bucketful , hitting the mix with water from a hose to soak it, and then repeating the process until the pipe is full of damp cement.
(Did this when I erected my back fence (dug a hole big enough to take a full bag of cement mix , stuck the RST fence poll in , leveled it , and dumped the cement mix in dry and hit it water until the cement couldn't soak up more).Did this for each fence poll.
Biggest disadvantage of a concrete fixed pier is it is there forever , not future proof. I can live with that.
Last edited by Ian Robinson; 13-11-2008 at 09:19 PM.
WALLS : Treated pine decking -outside, Inside AC Sheet
HEIGHT : 1.8m Floor to bottom of roof (I dont need to duck). With my electric pier I can nearly see the horizon.
FLOOR : Cement (1m cube below pier) and lino to slow dust
If you keep it simple it is not that expensive.
I have seen some sheds posted on the Yahoo group, they all seem to weak as the roof is part of its structual design. If you modify it you will need a lot of bracing to compensate. Also they are not as easy to secure.
- Dave.
Quote:
Originally Posted by Ian Robinson
Dave,
.... you did a great job.
How tall did you settle on for your wall height ?
the flat slidding roof looks pretty good.
Is that roof the same stuff I'm looking at (SPACEMAKER1000) ?
I sent off my faxes to the local Bunnings and Mitre10 to ask for quotes on materials including prefab timber wall frames this avo .
FWIW, I've built a "reflex" roll-off roof(?) I have effectively divided my available 3.5m by 8m ground space into two. One half is set up for the pier and scopes, while the other is my 'control room'. The control room has a fixed gable roof, but the viewing room has a higher sliding roof that slides back over the viewing room roof. ( I did/do not have space to have the roll off section hanging out one side when viewing.)
Also my horizon is not particularly clear, so my concrete pier is quite tall, and I've built a raised timber platform around it to walk on. Generally though imaging close to the horizon does not produce good results.
Built in stages, it was not overly expensive for me, I'm guessing about $3k all up.
A couple of pictures attached at mid-build.
I can provide more detail if interested.
Rio?, nup, its hardly an industrial application. My quickset pier does the job, period. There is much angst on the merits of steel/concrete piers. Steel needs subbies=expensive, concrete=do it yourself. Steel is good for removing/low thermal mass (yawn, do you have a 32" RCOS, where its makes a difference?). A concrete pier is way strong enough. Have you heard of a collapsing pier due to no rio?
Rio?, nup, its hardly an industrial application. My quickset pier does the job, period. There is much angst on the merits of steel/concrete piers. Steel needs subbies=expensive, concrete=do it yourself. Steel is good for removing/low thermal mass (yawn, do you have a 32" RCOS, where its makes a difference?). A concrete pier is way strong enough. Have you heard of a collapsing pier due to no rio?
FWIW, I've built a "reflex" roll-off roof(?) I have effectively divided my available 3.5m by 8m ground space into two. One half is set up for the pier and scopes, while the other is my 'control room'. The control room has a fixed gable roof, but the viewing room has a higher sliding roof that slides back over the viewing room roof. ( I did/do not have space to have the roll off section hanging out one side when viewing.)
Also my horizon is not particularly clear, so my concrete pier is quite tall, and I've built a raised timber platform around it to walk on. Generally though imaging close to the horizon does not produce good results.
Built in stages, it was not overly expensive for me, I'm guessing about $3k all up.
A couple of pictures attached at mid-build.
I can provide more detail if interested.
BC
Steel fencing stuff on the outside of the walls is an option , damned easy to attach to timber , also considering Hardyplank.
Wife tells me the shed better not become an eyesore , she wont be happy if it does.
Another option for the roof : a convex curved roof.
One option I am thinking about is using factory formed convex Zincalum roofing in my shed's roof .... this is better than a sprung convex roof I suspect , wont pop and ping as it expands and contracts like sprung roofs often do - (more rigid than straight roofing sheets) , I need to check that with the supplier (as it will naturally be convex curved , makes the construction of a rigid and strong roof much simpler I expect).
ie see attachments .
Anyone had any experience with this type of roofing ?
....Probably a dum question but it will govern the max height of the pier the Atlux will live on assuming I keep a big part of my low southern sky below the SCP.)
about $120 all up from a timber merchant (wholesaler) in hardwood not the big green (B's)
, I'm not a gingerbeer for nuffen !
