Rusted

Wit of man? WIT OF MAN? A few leaks? I have the equivelant of a town's drinking water tank up there! Hipsters will be fighting to buy it up to convert to a <cough> highly <cough> des. res. Just to get on a TV "challenging, grossly undersized, architecture" show. But I have a plan.

Thanks Gordon. I used black EPDM "lake liner" for my dome skirt. It weighs a ton! It is available in other colours but I haven't found any in Denmark so far. My dome would be partially visible, in the distance, only from the rural road about 150 yards away. The 20' hedges are growing rapidly so the dome should soon be completely invisible. We put up a 1m, grey satellite dish once and it stood out like a sore thumb in the distance! We did some more colour testing recently with any handy sheets of stuff available. It was very illuminating. Everything looks lighter, brighter and much bigger up there. A common illusion used and abused by the classic garden designers for slave drivers, stately follies. White, lightweight, PE tarpaulin looked lie a hot air balloon had crashed in the garden trees! 😱 Light grey looks white. So we are still aiming for a sage green. Which has proved a remarkably invisible colour at any time of year. Recommended! The dome is almost buried in deciduous trees now. Pulsar "Grass green" is just too strong a colour and rather too dark in our entirely personal opinion. PVC tarpaulin is rather lighter in weight than EPDM and readily weldable with a heat torch. My dome is all straight lines so doable in shaped gores, from flat sheet, without spherical distortion. Colours available to taste if you get away from the discount, ready-made tarpaulin, stockists.

You'd need a very thin head at certain times of the year to get behind the binoviewer. My dome base ring gets in the way and rotation of the Lacerta in the focuser really doesn't help. Hence my warning about the Brewster Angle on the Lacerta. You need lots of room behind the telescope which I simply don't have with my 7" f/12. My mounting is above head height and I'd still need to be a limbo dancer in the summer. Bung a camera on the Lacerta and it doesn't care about telescope orientation.

A heat gun risks serious damage to the optical components within. Red Loctite takes quite a bit of heat 550° to break down. That's well up to top heat setting on some guns.

The eyepiece unit is best unscrewed with a "Boa" type of oil filter remover. This has a tough rubber strap to avoid cosmetic damage. I clamped the black metal body down [with protective padding] before applying torque to the eyepiece unit.

Thanks Dave. I did some homework and zinc is four times heavier than aluminium and quite costly too. There is also the problem of having to cut literally every panel [of 60!] to fit. Which was what I did with the plywood using a sled on the table saw. Starting a new build from scratch I would make every gore identical. I heard back from Bresser and they are still looking into delivery costs. Having raised Gordon's suggestion of a box van they say they would worry about damage in transit. Pulsar used split pipe insulation for the lorry journey over to Bresser. With the lorry packed tightly with dome parts. I was quite mistaken in thinking they used pallets. I must have seen that in another video somewhere and filled in the blanks. Delivery using large pallets forces the use of a much larger vehicle with increased delivery costs. Then a fork lift is needed at the other end to unload the pallets. How that works with back garden installations is a further problem. Not everybody has access to a gang of willing volunteers. The MD was not amused by seeing the dome in white! 😱 Not sure whether a white Pulsar would look much smaller with its low profile shutter and smoother exterior. I suppose I could throw a shade net over it to make it look green. The MD suggested I put the drive electronics in a plastic lunch box and wear a cagoule when it rains.

Thanks Dave. Which part would the roofing company be doing?

Another option rears its head: Peter's aluminium, semi-cylindrical domes inspired me to think again. I'll build a whole, new, all aluminium 3m+, trapezoidal dome. Full gores in one piece of aluminium with neat bends at the changing angles. 'T' profile ribs. Notched in the 'T' upright at the angles and bent to close the angles. Pop riveted together. No special tools required. A few hundred quid in materials. Build it on the ground. Lift it "upstairs" as pairs of, or single gores. Aluminium will reflect the surrounding and overhanging trees and the grey sky. Blending into its surroundings far better than any white dome. I just tried covering the dome with a white tarpaulin and it was LOUD! A new dome can be built for less than the anticipated cost of delivery of a smaller, GRP dome. Lightweight and easy to move, build and handle.

Thanks Peter. Your semi-cylindrical domes have always appealed. Sadly I couldn't get a local engineer to roll the end "ribs" from 60mm alu. angle. Aluminium reflects the sky so isn't quite so obvious as snow white for most of the time. But does an aluminium dome get warm? This is the most vital aspect for solar imaging because most sensible options will stop the rain coming in anyway. The expensive marine sealant is cracked all over. The ply is rough all over the top surface under badly flaking paint. So it is finished unless I do something and very quickly! Too late for paint. Don't want to fibreglass. I am still wide open to different options but thinking of the best thermal performance for solar imaging. So I am now researching cladding the existing dome with full drops/gores of white, heavy duty, PVC tarpaulin. PVC is great for weather proofing the existing dome within any reasonable lifetime. Low enough skill required for me to manage the job hanging upside down from a cantilevered ladder. I have no white PVC to test but light grey gets warm in sunshine rather than hot. I'm thinking of heat welding the seams with a heat gun at the edges rather than risk taping. I think it will look quite smart rather than an eyesore. I'd be very grateful for any input on the practicality of the tarpaulin cover.

Thanks Gordon. When it is our own money vanishing through the observation slit we are bound to worry more. Still waiting for an answer from Bresser. I am [obviously] no lawyer, but I believe they have placed themselves in a very awkward legal position by including the "calculator" on their sales website. If the standard rate for delivery coughed up by their "calculator" is €70 then that is [surely] the flat delivery rate across most of Europe? I checked a random range of European countries on their "calculator." They all show €70 except for Bulgaria at €650. Ouch! That singular example of a variation on €70 is surely the determining factor? All others may pay [only] €70 for delivery. They may claim their get-out clause is that they have to arrange individual delivery contracts with carriers. Yet absolutely no mention of increased costs is included in their literature. We are then invited to use the calculator immediately below to asses our country's delivery charges. I did some online research on the subject and it is a red hot potato with many consumers. Furniture hidden delivery charges are a prime example. The gist of which is that, WE as customers, ABSOLUTELY DETEST hidden costs and sales are often cancelled as a result. No doubt there is Europe wide, consumer law covering the subject but I didn't delve that deeply. Were I still in the UK, a quick call to the Local Trading Standards Office would almost certainly enlighten me.

Thanks Gordon. The reference to "low loaders" was my [less than subtle] attempt at humour. I was going by the description given by Bresser's contact whom mentioned two large pallets. In fact Pulsar shows the dome sections already palletised on their Facebook page. I take my homework seriously just like any other self-respecting, obsessive-compulsive shopper for obs. domes. In fact I came very close to buying a 2.7m a year or so ago until I realised my 7" f/12 just wouldn't fit. I must have seen every single dome video on YT more than ten times by now. Read the pulsar website dozens of times in case of change. Pulsar were talking about a 3.5m model but gave up on the idea. Shame because I was very interested in one.

I'm not buying it from FLO Dave. I live in Denmark. So a European distributor makes sense. In this case Bresser is the major European distributor for Pulsar according to Pulsar's very own Facebook entry. [with pictures.] Bresser has a different web page. One with a calculator which shows €70 for delivery to Denmark.

The Lacerta 2" heat sink does indeed get hot when fed by a 180mm 7" refractor for several hours. I have burnt my hand [only briefly] through carelessness, but as already stated, there is no [hot] exit beam like the old fashioned wedges.

There are retailers in the UK who have paid a large fortune in fines over the years for having different prices in the shops from those advertised. Huge fines for repeatedly having different prices on the checkouts from those marked on the shelves. My fuzzy understanding is that they have to sell at the marked price. Why bother with a "pretend" calculator when it is meaningless nonsense? Why choose €70? Why not €7 or €7k? Click bait? Because €70 sounds "friendly?" So, once you express an interest you feel under pressure to continue regardless of their demands? The price you pay for any item inevitably includes the delivery charge. Sales often hinge on the TOTAL asking price. People pick and choose from eBay dealers depending entirely on the TOTAL price. They aren't idiots. £1 for the goods + £100 for P&P? Good luck with that as a business model!

The "universe" and Bresser are out to get me! They admitted the €70 delivery charge was a fiction! I can feel a missive to Margrethe Westager in the offing! Bresser muttered something about needing police outriders for the two, heavy transport, low loaders. I don't care how much practice they've had with wind turbine blades.. they'll never get those down our drive! More later.

I had holes drilled in my brake levers until I hit a security gate at work. Ouch! Relevance? Probably nil. But read on: What about bunging the guts from the Tak in another tube to be amply drilled to taste? Mr Drew Esq. could probably whip up something in a nice bit of 6" grey PVC drainpipe. Might even do it in "ally" if you have the necessary funds. 😱 Suits you sir!

That were me m'Lud. Guilty as charged. I regularly use my 2" Lacerta as a finder simply by watching the sun's huge image fill the heat sink through the window in the bottom. As the sun rises higher in summer it can be difficult to get behind or below the Lacerta for visual or binoviewing. The Brewster Angle is not as comfortable as the usual 90° jobbies in that respect. If you are using a camera then you won't care. The rotating top section of the Lacerta is handy for housing a single polarizing filter for dimming to taste and/or needs.

Thanks Gordon. Why worry?

I have a 10" f/8 1/30th wave mirror from a famous US mirror maker. Even when it was badly colimated it could show Plato craterlets without even trying. I tried to be clever in an OTA duplex beam design, but it never worked successfully. Torsion resistance was very poor on an equatorial. Just reaching the eyepiece needed a ladder. The mirror has never found its way into a "proper" tube to prove its true abilities. I made a cardboard tube and it weighed a ton and sagged. Dowels in rings were even worse! I used big saucepans for the cells. The "prop" is just a measuring stick. The 'tiny' mounting underneath is a Fullerscopes MkIV.

Thanks Gordon. I look straight across at the dome from my upstairs computer window. Sadly, the dome is looking less than smart since the paint started peeling. The birch plywood surface is getting very rough in places from water penetration. A hired, telescopic lift would get it back down for a fibreglass overcoat on the ground. The work involved just does not appeal at all. It had its chance and it simply failed to last. Time to move on without regret. It was enjoyable and demanding work to build. So it owes me nothing but fond memories of a successful project which still fills me with pride and little awe. Those who consider a plywood dome should factor in the fibreglass coating as vital to longevity. It completely revolutionised my observing and now I am imaging quite successfully after decades in the doldrums. Those without an observatory cannot possibly imagine the value a dome brings to observing and imaging. I can be imaging in a couple of minutes from scratch and walk away knowing it will come to no harm. I go indoors for meals and it will all be there, ready and without any delay, when I return. This is invaluable in cloudy weather because I can sit and browse in comfort until the sun reappears. Whole days pass as I quietly capture videos and images without ever leaving home. That is absolutely priceless to someone who is retired. It gives real meaning to my life and I am always within earshot of my wife. An ROR would need constant supervision in changeable weather and provide absolutely no shelter from the burning sun.

Thanks Gordon. You will be the first to know the truth once I hear from Bresser. As will everybody else here of course. The price for a fully automated Scopedome is indeed very close to a Pulsar with all "the hidden extras." The Scopedome just doesn't appeal for my unique situation. I would have to rebuild the entire structure from the ground up to make it fit. The Pulsar is a simple, flip-top head job for my particular build. I get to keep my building with everything I have tailored and improved since I built it. Security, access, monitor and electronics, Wifi, swivel chair and imaging desk wrapped around the isolated pier. Nothing changes except I will no longer need a bathing cap.

Thanks Gordon. We shall see what they say when Bresser are back in the office. They surely can't claim a few days to deliver if they have no stock? That would be called false advertising. Likewise, the delivery fee. It would have to be "ballpark" or it would be false advertising. Or click bait. There are national and European laws covering false advertising. Not to mention the bad press on the specialist astro forums. That's an extremely narrow customer base to be messing about. Absolutely no plans for automating the dome at that price! Besides, I only need a nudge now and then for solar imaging. I have all the lifting equipment I need from the last build. Chain hoists, boat winches and several yachting block and tackle sets. My dome is 3m Ø. So the 2.7m would, probably just about fit inside. I need a slightly smaller base ring to support the Pulsar rotation ring properly. Other than that and careful levelling I see no real problems on a still day.

I should have added that a stumpy tine, fork mount would add useful headroom for a longer OTA. Without the present considerable GEM offset I'd then have room to spare. Some completely unnecessary illustrations of the original build and my techniques for working alone up high:

Thanks Gordon. The 2.7m Pulsar drop-on lid suits me just fine. I wanted one when I first started my build. At that time I was still using my 7" f/12 as a straight tube and it was tight fit even in my larger dome. Bresser-De are the European distributors for Pulsar now. Very short delivery times are promised. I'm looking at €70 [website auto-quote] for home delivery from Germany to Denmark. The bank holiday weekend has intervened in ordering progress. PULSAR 2.7 METRE OBSERVATORY SHORT HEIGHT | Bresser I'm hoping I can build the dome in place like I did my own ply and timber dome. Failing that I can hire a telescopic lift for the whole dome. [Prefer not to.] I built my own dome "upstairs" in segments using braced, builders stepladders. So I think I can manage the 2.7m on a still day. Pulsar really ought to provide individual panel weights on their website, but don't. Customers could then judge how much voluntary help they need on the big day. Has anybody actually weighed their 2.7m bits and bobs prior to or during assembly? Any opinions on a one man band build 14' off the ground?

Thanks Dave. Though I fear you underestimate the problem. After some early imaging, this morning, the sky turned dark and started tipping down. To the thunder of wind-driven rain on plywood, I could add the steady plops of water. Dripping into large containers arranged on the floor. Which already have an inch of water from yesterday's deluge. If it gets any worse I shall become a poor imitation of an aquarist. Rather than a poor imitation of an amateur astronomer. I am committed to fitting a plastic lid on my octagon. Life is indeed far too short to be wasted on precious, summer months of sanding and painting. Only for it to be required all over again next year. The cost of replacing all my kit after a single drenching would soon exceed that of a new dome. The trapezoidal dome was great fun to build but has proved that GRP is vital to waterproofing ply. Now I shall cut out the middle man and go straight to the finished GRP jobby. Any Dane who wants a free 3m dome, to fibreglass themselves at ground level, can take it away. It will be in segments on the ground [for a while] to be quickly removed by those who want it. NO time wasters! I built it that way so it would always come apart. Hundreds of hex socket stainless steel, machine screws and SS washers hold the ribs together. With the Pulsar I gain thermally on better seeing, ease of use, waterproofing and improved user comfort. A replacement base ring is all I need to support the new dome's low, rotation wall at the existing sill level. I can retain everything I have built so far with only the loss of about a foot on diameter at base ring level. My ply dome has deeper ribs so the difference in useful diameter isn't really that great.