Doomed Dome

[Scott]

40 minutes ago, Cozzy said:

Doh, Absolutly brilliant, nice spot; never even clocked that. ??

I've never done that... well not this week anyway

 

[Rusted]

Rog never updated... should we worry?

[DAVE AMENDALL]

Hi All, Not wanting to hi jack Rogs post,I certainly sympathise with WilsonM's post.That'a a real nightmare when you think of the money involved. I was lucky when I ordered a Pulsar 2.2 metre observatory a couple of years back,they could not supply. Wanting a dome, I looked for alternatives. Mine is shown in the atatched picture.The dome is moulded in one piece. The fibreglass is heavy duty. The door is moulded with heavy duty top and bottom locking system. The shutter runs on tubular steel runners. The dome revolves on a stainless steel ballrace. The price was no more expensive. The building is very strong,and stands up to the elements very well. Top quality. I am delighted with it.Like I say, I was lucky that Pulsar did not supply/They did refund my deposit however..........Dave

Edited June 17, 2018 by DAVE AMENDALL
ommission

[Gina]

Looks a nice dome.

[david_taurus83]

From past experience, from my younger car modifying days (think Nissan Skyline) I realised that GRP bumpers and body panels were of constant rubbish quality as no matter how good the original mould is, the fibreglass never retains its intended shape. Close, but never exact. I'd steer clear of fibreglass domes all day long. As bad as I am as a wood worker, id give a timber obsy a go if I could.

[JeremyS]

I've had a Pulsar 2.1 m dome (see my avatar) since 2004. Best astro purchase ever. It's in use practically every clear night had has never caused problems. It does need buffing up from time to time to keep the shine

[DAVE AMENDALL]

Must agree with you Jeremy. Seems if one gets a good Dome that's  lucky, and it can be the best astro purchase of all.  If one is unlucky, then really they should be asking for a refund....Dave

[sloz1664]

I agree with both Jeremy & Dave. My Pulsar 2.1 M Dome has totally transformed my love of AstroPhotograhy. Even more now it's motorised.

Steve

[Rusted]

Orbsey is no more, it is dissolved, deceased, gone to the observatory in the sky...

[Stub Mandrel]

If I had a dome like that I would have to fit a serious sound system to it and call it Malcolm...

[tomato]

New Pulsar domes are pricey in my view for what they are, so that’s why I went the 2nd hand route, only to discover that the older versions are not compatible with Pulsar’s drive kits. Mind you at £2.5k for the dome and shutter kits, they aren’t exactly cheap either. 

So will be going the DIY route for this, thanks to the many useful posts on this subject by the SGL community.?

[sloz1664]

1 hour ago, tomato said:

New Pulsar domes are pricey in my view for what they are, so that’s why I went the 2nd hand route, only to discover that the older versions are not compatible with Pulsar’s drive kits. Mind you at £2.5k for the dome and shutter kits, they aren’t exactly cheap either. 

So will be going the DIY route for this, thanks to the many useful posts on this subject by the SGL community.?

I agree they are pricey, particularly the add-on kits. I purchased my Dome 2nd hand and added my own drive system & control it with LevesDome software.

Steve

[DAVE AMENDALL]

True Steve They are expensive but so is everything else My Obsy is not available anymore, but there are alternatives, My friend in Tenerife has this one NexDome Complete Observatory 2.2m.pdf...............Dave

Edited June 19, 2018 by DAVE AMENDALL
omission

[Gina]

Shutter doesn't open very far.

[DAVE AMENDALL]

you are very observant today Gina. now you mention it no it does'nt. Probably needs setting up properly using the Black & Decker orange drive unit and micro switches.............Dave

[DAVE AMENDALL]

Don't think a calf rearing igloo is really the answer. Sort of thing you would find in Finland or Scande Too heavy Too much work on conversion. A silo top would be better      Dave

[Rusted]

Allow me to disagree, Dave.

Silo conversion is very hard work geometrically.

Particularly if you want to view beyond the zenith.

Being galvanized steel, they are sharp, heavy in any useful size and difficult to cut.

They also have weird, structural hoops which may impede the observation slit.

GRP work is relatively low skill and uses everyday tools.

Yes, it produces itchy dust and needs a proper mask and goggles.

Though lots of users do seem to survive to tell the tale. 

EDIT: There are UK dealers:

Some links:

http://www.holm-laue.de/index.php/iglu?ln=en-GB#ad-image-0

Holm & Laue GmbH & Co. KG | Iglu

Calf Husbandry, Calf Igloos & Verandas | Calf Igloo

BTW: I'm fairly sure my completed 10' plywood dome is going to be heavier than the 14' calf igloo.

Edited June 21, 2018 by Rusted
Add info

[Peter Drew]

+1 for avoiding steel silo dome conversions. I did a 26ft one and it was an absolute nightmare for the reasons @Rusted listed.

[Gina]

WOW that was a massive job Peter!!

[DAVE AMENDALL]

Points taken I must stand corrected. I did not think it through. Those silo tops look so attractive on top of towers down on the farm. I saw the 10ft plywood dome on your website. Clever construction.Not everyone is handy enough to do it. It's easy to see why the commercial fibreglass domes have become so popular in recent years. Here is a heavy wood construction which has worked well for years.........Dave

Edited June 21, 2018 by DAVE AMENDALL
omission

[Rusted]

What's the history of the wooden structure, Dave? I can't even imagine the weight of the rotating parts.

 

Convenience and a ready-made solution are probably worth the premium of buying a commercial dome.

But only if the solution really is convenient, offers instant gratification and long term satisfaction.

Building a DIY dome is expensive and hard work over quite an extended period.

It is only rewarding if the result lasts and you place absolutely no value on your own labour.

Imagine if I had paid myself only £10 per day for my own labour. That would have bought a Pulsar dome by now.

Unfortunately [?] Pulsar did not offer anything large enough to house my instruments of choice.

The upside is I get to use my brain and stay fit into old age as I ponder the wisdom of making so much noise and sawdust.

The cost in tools and materials has never been calculated but I bet it probably makes a Pulsar dome seem quite good value.

Fiberglass domes are much lighter than wooden constructions. So might actually be much more user friendly than wood.

Never enter into such a building project unless you have both eyes firmly closed to reality.

Don't be fooled that you will save any money [at all] unless you have some useful skills or badly need a project for your own sanity.

Take Peter's lead and build a half cylinder. You know it make [little] sense. 

[DAVE AMENDALL]

The  Wooden Observatory dates back to the Patrick Moore era and was constructed at Severn Oaks and was used for many years by a certain Commander Hatfield. It housed one F8 12" Newtonian And a large photographic Schmitd camera. The rotation system is just below the window. The wheels were squirreled from hospital beds twelve of them in all and run in a heavy duty circular steel runner. The system operated manually by chain and crank. Turns smoothly and easily enough. The shutter opens to the zenith. The shutter rails can be seen on the picture. Very old fashioned at modern standards. I would assume needs constant maintenance and weatherproofing.Fascinating nevertheless....Dave

[JeremyS]

6 minutes ago, DAVE AMENDALL said:

The  Wooden Observatory dates back to the Patrick Moore era and was constructed at Severn Oaks and was used for many years by a certain Commander Hatfield.

I visited that observatory many times as I lived quite near Commander Hatfield when I was at school. Lovely structure. Last I heard (many years ago) it was moved from Sevenoaks to Christ's Hospital School in Sussex..Glad to hear you are still making use of it Dave. is it in Nottingham?

[Rusted]

55 minutes ago, JeremyS said:

I visited that observatory many times as I lived quite near Commander Hatfield when I was at school. Lovely structure. Last I heard (many years ago) it was moved from Sevenoaks to Christ's Hospital School in Sussex..Glad to hear you are still making use of it Dave. is it in Nottingham?

Hospital School? Perhaps they wanted their wheels back? 

[Rusted]

1 hour ago, DAVE AMENDALL said:

The  Wooden Observatory dates back to the Patrick Moore era and was constructed at Severn Oaks and was used for many years by a certain Commander Hatfield. It housed one F8 12" Newtonian And a large photographic Schmidt camera. The rotation system is just below the window. The wheels were squirreled from hospital beds twelve of them in all and run in a heavy duty circular steel runner. The system operated manually by chain and crank. Turns smoothly and easily enough. The shutter opens to the zenith. The shutter rails can be seen on the picture. Very old fashioned at modern standards. I would assume needs constant maintenance and weatherproofing.Fascinating nevertheless....Dave

Thanks, Dave. I noticed later that the image was taken from a book.

One I have obviously missed.

The problem with any normal wood skeleton construction is the sheer weight.

We should be borrowing canoe and lightweight boat construction techniques.

Thin marine ply, epoxy, CF and disposable copper wire. Not heavy plywood struts.

Few domes will need to survive whitewater rafting.

Not unless sea level rise has been badly underestimated.

Edited June 22, 2018 by Rusted
typo