New Pulsar 2.2m Dome

[Steve 1962]

After four years of lugging kit in and out, and months of "umming and arghing" I've ordered a 2.2m dome from Gary at Pulsar as a 50th birthday present to myself. OK - it's hardly a very DIY approach, but I am putting in the foundations myself and doing everything bar installing the dome, so I hope it's OK to post updates here.

The process started when I had to apply for planning permission. Although a dome would normally be classed as a permitted development and would therefore not need planning permission, my home is a fairly recent barn conversion located in an AONB, and all of my permitted development rights were removed when planning permission was granted for the conversation.

Anyway, gaining permission was relatively painless and free from cost (apart from about £8 to get an OS licensed copy of the location plan). I made sure all of the neighbours knew what was going on and they were all very interested and supportive - especially given that (to keep my wife happy) the dome is to be green and therefore relatively unintrusive.

One thing that did go wrong with the planning process was that a clerk at the councel must have read "Observatory" as "Conservatory" so the application was incorrectly logged at first. This was corrected but we're now being deluged with offers from builders and installers of conservatories as well as Velux blind and garden furniture suppliers.

It was my birthday in June, and we were planning a party in the garden so I was "instructed" not to make a mess of the garden before the party - the weather turned out to be awful and the party was held inside, so I needn't have waited, but I went to Ely to meet Gary (a very nice chap) at the end of June to see a dome in the flesh and I ordered a 2.2m dome in green with one equipment bay for delivery in September.

The DIY element of the plan is to install a home made 1m tall pier made from concrete filled 300mm diameter air-conditioning duct topped with a pier adaptor from Rob at Epsilon Telescopes (another thoroughly nice chap) on which to mount my NEQ6.

The pier will sit on a cubic metre of concrete which may be overkill but it's built up ground and I don't intend to do this job twice. The pier base will be surrounded by a 2.4m diameter, 250mm thick round concrete slab which will be isolated from the pier with a closed cell foam spacer. Mains power is already at the bottom of the garden and I'm going to run a Cat5 cable out from the house so that I have a gigabit LAN connection out there to allow remote operation of the kit and an alarm cable which will link into the house alarm.

I'm going to install a raised and insulated floor inside the dome with space to run cables underneath. The floor will be covered with recovered used carpet tiles.

In the long term I'm going to build an arduino based dome rotation stepper motor controller..but that's a way off yet

We did the digging yesterday and removed about 2.5 cubic metres of very hard clay and flint, so here's the first picture of the site.

This view (looking NNE) makes the site look quite "tree'd in" but I have relatively uninterrupted views all the way from ENE through S to NNW overlooking the Blackdown Hills. The willow tree in the left background of the photo obscures slight light pollution from Taunton about 6 miles away.

In case you're wondering why the hole for the pier is a bit of an odd shape, this was because we had to remove (and replant as part of the planning permission granted by my wife) a small tree which was in the way.

I'm going to concrete in the pier next weekend (weather permitting)..so more pictures will follow soon.

Steve

[teleskopjo]

Good luck and well done!

Hopefully the green colour wont allow it to heat up too much inside!

[Steve 1962]

Good luck and well done!

Hopefully the green colour wont allow it to heat up too much inside!

Thanks teleskopjo - I think it's bound to be warmer than a white one but hopefully it'll be OK - a white dome wasn't an option with my wife, the planners or my neighbours. A friend has a green Skyshed Pod and that's not too bad - hopefully it'll just need to be opened earlier for a longer cool down.

If needed I could add some forced cooling.

Steve

[Gina]

Lovely Nice start and coming on nicely - I know what a hard job digging out a big hole is with the various size stones and clay in the area. I'm up in The Blackdown Hills on the NW side of the Otter Valley. The view here is limited in the north and west but good round from NNE round through south to SW. We use the VETs in Wellington for our animals. Good luck with your observatory I always think a dome looks like a proper obsy but I'm very happy with my roll off roof wooden shed.

[Steve 1962]

Good luck with your observatory

Thanks Gina.

Well, we were rained off last weekend, but at 07.15 this morning my mate, Stan, arrived to give me a hand concreting in the pier.

In the end we set five reinforcing rods into 600mm of concrete in the bottom of the hole, let the concrete go off for an hour, then we set the 300mm aircon duct in place, built up the base by 300mm around it and then topped the pier up. Two and half tons of concrete in all!!

The plan now is let this go off for a week or so and build some circular formwork around it for the dome base. I'm going to isolate the pier from the floor with closed cell insulation over the pier base and around the bottom of the pier, then it'll just be another cube or so of concrete..and job done (hopefully!).

The aircon duct isn't cut off dead square, so once the concrete has gone off, I'm going to file it down level.

I'm feeling pretty chuffed with our morning's work, there's no mess, so SWMBO is happy and pier is dead plum. Off now to the NLO

[ollypenrice]

You won't have any problem with green. A few years back someone else was making GRP domes and green was the default colour. We had one at our club, in fact.

Enjoy the project!

Olly

[Steve 1962]

Thanks Olly!

[Steve 1962]

Latest update - this weekend I've cut out a circle of reinforcing mesh ready for the slab to be cast next weekend and I've set some M10 stainless steel threaded bar into the top of the pier using resin anchor.

Here's a picky of my NEQ6 sat on the MPS adapter and custom made cap plate from Epsilon Telescopes. http://www.epsilon-t...s.co.uk/mps.htm (the black cap plate is covered with plastic to protect its finish during construction). The height of the adapter is to allow the pier to be about 1m high and enable the fitting of a bigger mount (he coughs, shuffles feet, looks nervously at wife) in the future.

Strewth - it's hot here today!

[Gina]

Oooh - nice pier

[Steve 1962]

Thanks Gina.

I've just ordered some nice stainless steel dome head nuts to finish the studs off after I've cut them down a bit.

[JamesF]

Looking good so far. Should be great once the dome arrives.

James

[Steve 1962]

Well, we've finally had a couple of days when the weather's been favourable(!?) , there's been no family or work commitments, and my brother-in-law, Kevin, and mate, Stan were free, so we've now finished the plinth for the dome.

Yesterday, Kev and I built round formwork using two layers of 5mm polycarbonate that Kev scrounged from the waste skip at Debenhams (thanks guy and well spotted Kev - perfect!). It was a major problem getting the formwork round because whenever we hammered in a stake, we hit flint - hence the odd angles of stakes in the photos.

The plinth is about 300mm thick to cater for the slope across the site and is reinforced with mesh. Stan thinks it's well over the top - and I tend to agree but I'm only going to do this job once! I do feel sorry for the people that buy our house in future though.

We covered the pier footings with 50mm of insulation and wrapped the bottom of the pier with a camping mat to isolate it from the plinth. For the cabling we've used surplus guttering downpipe secured to the mesh with cable ties.

This morning Stan and I shifted about 1.5 cube of concrete and now have a nice smooth plinth.

Off now to ring Gary to arrange delivery of the dome!

Happy days.

[dmahon]

I see you paid them in Celebrations.

[Steve 1962]

I see you paid them in Celebrations.

No - they were there to lure Stan in - he couldn't reach them!

[Astrokev]

Really interesting project.

I have a couple of lengths of air-con ducting just like yours, sitting patiently in my shed, waiting for the day when I pull my finger out. My original plans were to make a roll-off roof, andthis may be what I eventually plum for, but of late I've been seriously tempted to consider a dome on a DIY base/walls, similar to your build, so watching your thread with great interest!

Look forward to the next installment.

[Bizibilder]

You certainly build things solid in Somerset! A very interesting project.

[Steve 1962]

but of late I've been seriously tempted to consider a dome on a DIY base/walls

Sorry if this disappoints you Kev, but I've bought the whole thing - walls 'n all - from Gary, so apart from the wiring and fit-out - that's the DIY done.

You certainly build things solid in Somerset

Yup, Roger, this isn't going anywhere (touch wood!) - it's actually pretty tight really - the plinth is only two inches out of the ground at the top and about 4 inches in the ground at the bottom of the slope.

Costs so far;

Labour to dig it out - £100

Skip - £118

Mesh - £14

Mesh "Turrets" - £4

Insulation - £9

Camping Mat - £4

Pipe bends - £15

Timber - £14

Concrete - £170

Total - £448 plus tea / coffee / beer / sandwiches and Celebrations for Kev and Stan

The prices quoted by local builders ranged from £1750 to £3000 PLUS VAT!

[Steve 1962]

Almost there.

This morning I've trimmed down the cable ducts and pier insulation to floor level, cut the pier-mount bolts to length and removed the form-work.

The form work came away easily, but I've got quite a few chips around the edge and holes in the sides - does anyone have any advice of whether / how to fill them in please? I'm think of a fairly strong wet mix of cement and cement just trowelled into the gaps.

SHMBO wants me to paint it green to match the dome...not sure myself

The dome arrives on the 26th. Yeha!

[Bizibilder]

If you still have a bit of ballast left over then sieve the largest stones out of it and mix up a "morter" - use that to fill any holes. Don't mix up with sand as it will dry the wrong colour and look horrible!

[Steve 1962]

Thanks Roger - we used premix, so we don't have any ballast - I guess it'll have to be sand and cement, then paint it!

[Scott]

looks really great there mate and i must say you have a beautiful looking garden as well. looking forward to the next installment

Scott.

[Steve 1962]

you have a beautiful looking garden as well

Thanks Scott - that's a bit of a sore point - my wife, Vicky, does the gardening (I mow the lawn though!) and she doesn't agree with me that the dome will make it more beautiful.

[Scott]

Thanks Scott - that's a bit of a sore point - my wife, Vicky, does the gardening (I mow the lawn though!) and she doesn't agree with me that the dome will make it more beautiful.

plant some nice low, slow growing plants around it and she'll soon change her mind.

surely an domed observatory in the back garden will give it an air of prosperity

[Tinker1947]

Thanks Roger - we used premix, so we don't have any ballast - I guess it'll have to be sand and cement, then paint it!

I think i remember with this type of hole fixing, bung in a drop of Unibond, will assist with keeping your mix in the hole.....

[Steve 1962]

Thanks Tinker1947 - all holes PVA'd and filled - two coats of masonry paint will follow during the week