I have been working on the idea of a RORO shed for some time and not really expecting to get the OK from my wife, but she surprised me recently by more or less asking why I had not started yet!
I plan to make space for at least two scopes on piers, my own CPC925 mounted on a wedge (Which I think I will design and construct myself as I reckon I can do cheaper and better than the Celestron one for a fixed mount) and a mates AP rig, think in terms of about 900mm FL refractor, currently used on a tripod when he comes out to my place to escape LP from Melbourne.
What would be the minimum width of shed people would consider (Length is another issue completely, more on that later) to mount the refractor in the middle, point it at the horizon (Which won't be visible) and allow space for set up/working on it etc. Basically, how much "Walking around" space outside the envelope the scope will occupy would you want to have in an ideal world?
The second question would be wall height, how low to the horizon would you consider imaging? I am hoping to have the walls high enough to block stray light from car headlights as we are on a bend in a road and headlights sweep our place from side to side all the time. I was also thinking that matte black paint on the inside would be a good idea to help cut that problem even further, at least for the top half of the walls. Ideal wall height would allow a normal door to be used under the roll off roof without bumping your head!
My wife also made the suggestion of a section of the shed partitioned off from the scopes and weather protected (The length issue) to allow for a couple of bunks for those long imaging sessions! (I think she just wants us to stay out there and stop bumping around the house at 3AM looking for whiskey) If I were to add a bunkhouse, is there value in cable extensions so that laptops for imaging could be put in there? I can see an obvious benefit in reduction of stray light when capturing images if laptop screens were out of the way with walls between them and lense, but does it matter?
Piers, I plan a concrete floor in this for cleanliness, is there real value for imaging if the pier is isolated form the shed floor? I have a 12" post hole auger on a tractor which I can sink to about 800mm to put in a footing for a pier, am I best off to carry this 12" above the ground a little (Thinking of stubbed toes here) and use the rubber isolator/expansion strips they use nowadays in concreting to prevent contact between the floor slab and pier base? Visually I can not see it making any real difference, but photographically? I would hate for us to have to spend the night making sure to sit still to keep vibrations at bay.
This could end up more comfy than my house, but I will only get one shot at this, so any other suggestions for an ambit claim for the "Features"?
This is also going to be a project of quite some time in the making, probably starting with piers and then a slab and finally a shed, but if I am going to move to that last stage and build a shed over it all then I need to get the dimensions right from the beginning.
Last edited by The_bluester; 01-04-2014 at 11:16 AM.
Paul,
I have an e-book called Building a ROR Observatory: A complete guide for design and construction, by John Hicks.
It's 5 MB pdf file, so happy to share it with you.
PM me with your email address and I will send one through.
Cheers,
Bo
On to another question, if you were going to make your own wedge, out of alloy for preference, how thick would you make the support plates to mount the wedge to the pier and scope to the wedge? I was thinking about 12mm or so
I am thinking of a fairly simple design made up of two plates, a base plate to mount to the top plate of the pier, which has three slotted holes to allow mounting on the pier (Radially slotted to allow the azimuth adjustment to be fine tweaked) which will have two mounting ears sticking up on what will be the southern edge, with holes drilled for altitude bolts (I am seeing NC milling in the future)
The second plate will have matching ears milled into the bottom face, spaced to be an almost interference fit between the other two. This will allow nyloc nuts on stainless bolts to lock the altitude. The shank diameter of the bolts needs to be a tap in fit in the altitude "Ears" to reduce play when setting it up. Some fine thread on 12mm or thicker shaft to make an altitude adjuster would be the ticket too.
Alt may need an elongated radial hole in a locking bar each side to allow for a small amount of adjustment in order to lock it up dead tight? (Taking inspiration from the side plates on the Celestron wedge) The intent would be for this to be an equivalent to the Celestron HD Pro wedge but it does not need the adjustment range of the genuine one as it would be purpose built for my location and only need a couple of degrees adjustment in any direction in case of designer/constructor (Me) error.
Setting the altitude would be fairly easy with a threaded rod and I reckon I would steal the adjustment method from and old points ignition system for the azimuth, with a slot for the end of a screwdriver to gently lever it around combined with a crentral locating pin so you drive it around in azimuth rather than push it sideways.
After making a wooden prototype first, I used aluminium plate to make a fixed angle (38 deg) wedge for an 8" Meade. The base was 19 mm, the angled plate 10 mm and the gussets were 12 mm. It was very stiff and served well for visual observing for a few years; it's not used any more so I guess that I should unload it. Some pictures attached, plus a link to my construction thread, where the wedge can be seen with the LX90 attached in post #12 http://www.iceinspace.com.au/forum/s...ad.php?t=36222
The base is about 325 mm square, and the angled plate is about 250W x 270H - comfortably fitting the 8" SCT at the time.
Cheers, Chris
Last edited by ChrisM; 01-04-2014 at 09:42 PM.
Reason: added dimensions
I suppose I could do the same. Fine tweaking of angles would be a problem for photography though.
I am really torn between just handing over the cash for the celestron HD pro wedge or designing and building my own at probably 70% of the cost. I am not sure the work is justified by the likely saving.
I was planning on a 2.5 x2.5 m area for the scope and then a 1m by 2.5m area under cover for electronics etc. I would like something bigger however if you go over 10sqm where I live you have to go through building approval processes.
Due to the overlay our friendly council put over things (as far as I can see, to claw back control they lost when the state planning scheme was changed some years back) we will need a planning permit regardless, so I may as well go large!
Don't tell them. If it is small it should not matter. Council inspectors don't go door to door looking for violations. Unless you get a neighbor complaining they will never know. If you ever move, and the land plan is part of the sale documentation you could simply remove it (if its small). There is far too much of letting the 'authorities' determine what we can and can't do - be a rebel.
Actually, councils including ours have become known as avid users of nearmap which unfortunately includes hi res images of our place so changes stand out like the proverbial bits of a dog. The only way I may get away with it would be if I can make it a definable temporary structure. But even those they try to give people a hard time about.
Last edited by The_bluester; 02-04-2014 at 04:26 PM.
What would be the minimum width of shed people would consider (Length is another issue completely, more on that later) to mount the refractor in the middle, point it at the horizon (Which won't be visible) and allow space for set up/working on it etc. Basically, how much "Walking around" space outside the envelope the scope will occupy would you want to have in an ideal world?
The open portion of my observatory is 3m x 3m, with a PME and 12" SCT in the middle of that area. I've often given thought to adding a second telescope of similar size and have come to the conclusion I would want the space to be 3m x 5m, perhaps 3m x 6m if money and space were not an issue.
Quote:
Originally Posted by The_bluester
The second question would be wall height, how low to the horizon would you consider imaging? I am hoping to have the walls high enough to block stray light from car headlights as we are on a bend in a road and headlights sweep our place from side to side all the time. I was also thinking that matte black paint on the inside would be a good idea to help cut that problem even further, at least for the top half of the walls. Ideal wall height would allow a normal door to be used under the roll off roof without bumping your head!
My walls are 2.0m high. That height is generally good. I can image quite low to the horizon on three sides (guess 10 degrees most directions - ignoring trees etc!). I have a pitched roof (hence the scope is not entirely below the 2m height of the walls). The only problem is to one side where the pitch of my roof is and obstructs the north more than the other walls do. I don't have black walls, they are the standard colourbond under-side colour. I don't have a problem with stray light or such even with lights on, having the telescope optical path fully sealed and due shield on.
My door is a good height for me (me being 1.78m tall) but taller visitors need to be warned. There's also horizontal support beams inside the enclosed half of my observatory which cross at about 1.9m height so taller visitors require warning!. Problem with making it all higher is increasing the wall height. I can think of ways to get around this now - higher enclosed half than open half with taller "skirts" coming down from the rolling roof).
Quote:
Originally Posted by The_bluester
My wife also made the suggestion of a section of the shed partitioned off from the scopes and weather protected (The length issue) to allow for a couple of bunks for those long imaging sessions! (I think she just wants us to stay out there and stop bumping around the house at 3AM looking for whiskey) If I were to add a bunkhouse, is there value in cable extensions so that laptops for imaging could be put in there? I can see an obvious benefit in reduction of stray light when capturing images if laptop screens were out of the way with walls between them and lense, but does it matter?
I wouldn't be without the enclosed half of my observatory. Warm, comfortable, dust free, dew free, nicely set up, a space to spend time. Cable ducting from piers to nearest wall of observatory and then along walls to enclosed portion is essential. I used 90mm storm-water pipe under the concrete slab but even that is getting maxed out with cables now and I would've preferred two, one for power and one for data.
Quote:
Originally Posted by The_bluester
Piers, I plan a concrete floor in this for cleanliness, is there real value for imaging if the pier is isolated form the shed floor? I have a 12" post hole auger on a tractor which I can sink to about 800mm to put in a footing for a pier, am I best off to carry this 12" above the ground a little (Thinking of stubbed toes here) and use the rubber isolator/expansion strips they use nowadays in concreting to prevent contact between the floor slab and pier base? Visually I can not see it making any real difference, but photographically? I would hate for us to have to spend the night making sure to sit still to keep vibrations at bay.
My pier is steel, embedded in about a cubic metre of concrete and seperated from the rest of the concrete pad by rubber expansion foam. I think having it separated from the rest of the slab does help reduce vibrations. Amount of concrete is up to you or some engineer to guestimate I guess I'd recommend concrete pier rather than steel. I did have issues with vibration from my pier but filling it with sand negates that, but may as well be concrete I think. Most vibrations I've experienced come from wind which ripples over the walls.
Quote:
Originally Posted by The_bluester
This could end up more comfy than my house, but I will only get one shot at this, so any other suggestions for an ambit claim for the "Features"?
Nice sound system (consider wire ducting), consider wire ducting for ventilation fan(s) to cool down after a hot day or such (I have one in my enclosed half). I have insulated the enclosed half of mine which makes it comfortable but it holds way too much heat in summer. Definitely don't insulate your open half if you have a climate like Perth, except the roof with thin reflective insulation. Condensation inside the open half can be a problem during winter when it's closed up, so consdier options for mitigating this so you don't have it dripping on equipment (the thin insulation on the roof would probably do it). Don't foreget to plan for remote operaiton, with ducted network cables, ducting to put weather station on top of the roof, etc.
Quote:
Originally Posted by The_bluester
This is also going to be a project of quite some time in the making, probably starting with piers and then a slab and finally a shed, but if I am going to move to that last stage and build a shed over it all then I need to get the dimensions right from the beginning.
These things are iterative and take time to progress. I've had mine for about 14 years now and it took a good 10 years to build it up to where it is now, comfortable and easy to use.
First up, thanks for a long and thought out reply.
Fairly much all things I had thought of myself, though I had not thought about putting a sound system out there. I do have an old AVR that could be pressed into service. With a wifi link back to the house it could even be used with a lean XBMC box to source the music off our server (All our media is on a NAS) or even cheesy movies that don't get the nod in the house! If we are imaging with laptops etc running then our dark adaptation is history anyway, we might as well watch bad scifi.
Good to see that I am not too far off in my thinking, though I possibly would not have allowed enough by way of cabling space which is ironic as I work in the comms industry, I might get a bit creative there and fit multiple 32mm conduits in the piers (multiple smaller ones to preserve the integrity, plus power cables could be run separate to data) and take them to a comms pit in the floor which can have a P100 conduit into the warm room to allow for plenty of cable space.
I was actually thinking of solar panels to run some ventilation fans to keep heat at bay in the summer and condensation in the winter and was thinking I would fully line the "Work" room. I Have to be careful now, my wife has realised that if I am at home but not in the house she sleeps badly. Best not to mention bunks!
Given my headlight sweep issue I am not too sure if I should go for lower walls and some temporary screening outside while appropriate height trees I will plant around it grow out to block light, or higher walls and not worry too much about the greenery. Higher walls could help with wind too but so would trees. Given some knowledge of windbreak lines (Largely lost in the fire unfortunately) multiple rows of semi wind permeable trees could be a real help where a single line of heavy trees actually creates turbulence, as might high walls.
I was also thinking to paint yellow circles around each pier, figure out the maximum envelope size of the mounted scopes and add half a mater. That way it should be visible in the dark and you can be happy that if you don't set foot in the circles as you walk past, you wont bump into anything.
Actually, councils including ours have become known as a id users of nearmap,which unfortunately includes hi res images of our place so changes stand out like the proverbial bits of a dog. The only way I may get away with it would be if I can make it a definable temporary structure. But even those they try to give people a hard time about.
or ... make it a childrens cubby house. attach a slide or something. just happen to store your telescope in there as well.
Maybe allow room for a beer fridge, perhaps under a bench with a spare monitor on top to plug into the laptop. If not bunks then maybe a stretcher /sleeping bag, and possibly install some form of heating to avoid relying on the polar suits in winter!
Have been thinking about the design of a polar wedge for my CPC 925. Trying to functionally copy the Celestron wedge is over designing it. Better to take some inspiration from the NEQ/other type generic GEM.
What I need is a small length of alloy turning stock, probably no more than 100mm (the base) into one end of which a groove can be turned about 10mm from the end, that allows for clamps to hold it down on a pier and if in a suitable round hole in a baseplate, also for the azimuth adjustment. The top of the alloy round stock would need suitable flats milled on opposing sides and two holes drilled side to side between the flats. One for a pivot bolt, one for an adjustment locking bolt.
Mounted via the holes would be a thick alloy plate on which the scope is bolted using the original Celestron points in the same way as on a celestron wedge. Underneath the plate, plate "ears" would need to be fitted to mount to the base.
Polar alignment would be fiddly, but it would only have to be done once. I will try to come up with a sketch in the next couple of days so people who have done similar can critique.
Sounds like things are coming together Paul.
Have you thought of using old disc brakes off a car to make the wedge, might be easier and already pre-mahcined.
RE the permit thing, it's a good thing you are following the regulation PITA as they may be. Just in case things happen (e.g. fire) and insurance may refuse coverage because the building was constructed without a permit.
Cheers,
Bo
Funny you mention brake discs, I saw that mentioned as a pier plate while trawling the net for ideas this week. I produce a ready supply of them. My other expensive hobby (Race car) typically produces at least two nice thick, heavy cast off rotors a year as we run cheap rotors on the front and chuck them away when they start to develop more than fine surface cracking due to heat.
It would not take much to drill through the friction area to dynabolt a rotor down and then have the alloy "Shaft" I mentioned above machined to fit through the centre bore to locate it, with bolt down clamps to keep it both stable and to lock the azimuth aspect of the mount. A couple of grooves in strategic sopts would allow a flat blade screwdriver to be used to move the azimuth around. I am thinking left and right hand thread spherical bearings with linking internal threaded rod behind the main mount plate for the scope to make altitude adjustment easy. They could be bolted on for adjustment and then removed when it was properly set up.
I am really glad to see this thread fly, while it is gong to be some time before I build, there has been plenty of food for thought for me in here and via PM already. The biggest being to fairly drastically upsize the pier footings to ensure stability and lack of vibration.
One thing I am really keen on though is a concrete floor, even it if is as thin as I can get away with to keep the thermal mass down. Raised floors of any sort will be a good environment for creepy crawly and slithery friends that I don't see much need for when I am walking around in the dar
Further note to self, multiple lighting circuits required, dim red for the obvious reasons in both areas and normal white lights as well, white lights to be on protected switches so a flap has to be lifted to operate them, avoids unexpected yelling in the middle of the night!
Sounds like a plan Paul,
Once I get my a$$ into gear, I might contact you and get a brake disc off you (won't be for a while though).
Also, if you are after some carpet offcuts, just PM me, I have a small roll that you can use to pad up the pier to save your toes/shins etc.
Bo
I'd recommend concrete pier rather than steel. I did have issues with vibration from my pier but filling it with sand negates that, but may as well be concrete I think. Most vibrations I've experienced come from wind which ripples over the walls.
