Work has started on Al's Observatory

[sheeny (Al)]

"Darryl dug a hole, Darl"...

Well, I've finally started to get serious about the obs. I started earthworks about 6 weeks ago, recycling part of a disused motocross jump into the fill required for the site of my obs. All fill moved by hand and barrow, and sheepsfooted by hand with the crowbar in layers of <200mm. After compaction, I let the site settle for a month. The compaction worked because I nearly needed the crow bar to get through the fill!

This afternoon I dug the hole for the pier. It's 350x350x700 deep including a 50mm key into the rock layer. I was planning to go a metre deep if I didn't hit rock. So the plan is to pour the pier this weekend.

I have the pier fabricated and the anchor bolts are welded into a cluster ready to be cast in. The formwork for the top of the pier is built with the support for the bolts ready to keep them at the right level and square during the pour.

Once the pier is poured, the plan is to pour a slab floor for the Skyshed POD around it. It will be isolated from the pier footing by expansion jointing. The slab will be 100mm thick with 1 layer of F52 mesh with a plastic water barrier underneath.

I chose to go with the concrete slab for two reasons: we will probably sell this place before I retire and the girls move out so a concrete slab will be an asset for a garden shed, and a timber deck in the climate here would be particularly cold with the wind whistling underneath. The pier footing will be level with the slab so when I leave I'll grind the bolts off and it's good to go for a shed.

The observatory is closer to the house than originally planned. When crunch time came to start work preparing the site, I worked through the design process again, and decided it was best to move it closer to the house where I can fence it into the house yard. I've managed to keep the visible horison to under about 10° altitude everywhere except south, but south isn't much worse. A number of factors influenced the decision: a wind sucking horse, security and convenience to the house.

I'll post more as it develops.

Al.

[Dennis]

Hey Al

That is terrific news – you’ll be the envy of the “drag it all out every night” paupers, me included!

Cheers

Dennis

[Matty P (Matt)]

Looking good Al, I'm looking forward to watching the progress.

Do you know when your POD will be arriving?

I haven't had any time to continue work on my ROR Observatory but will in about two weeks time. We are currently collecting parts for the pier.

[sheeny (Al)]

Originally Posted by Dennis

Hey Al

That is terrific news – you’ll be the envy of the “drag it all out every night” paupers, me included!

Cheers

Dennis

Oooooh yeah! I am soooo looking forward to it. I can't believe how little astronomy I have done since I moved. I have a dark sky site, but I've hardly made the most of it since I've been busy working on the place. I've got the most important stuff done now, so I'm keen to get the footing and slab done so when the POD arrives I can set up and play!

Originally Posted by Matty P

Looking good Al, I'm looking forward to watching the progress.

Do you know when your POD will be arriving?

I haven't had any time to continue work on my ROR Observatory but will in about two weeks time. We are currently collecting parts for the pier.

I spoke to Matthew a week or two ago and his best estimate was about 6 weeks. He said the PODs were being manufactured and he'd let me know a better estimate of time when they were all ready to be containerised. Then he'll have an idea of what ship it'll be on.

Al.

[Screwdriverone (Chris)]

Ummm,.... a "wind sucking horse"????

Please explain?

Chris

[gmbfilter (Geoff)]

Horses grab hold of something, like a fence post, or a rail, part of a stable, telescope, or an EQ6 with their teeth, pull their necks backwards and swallow air.

It's a nervous habit perhaps bought on by boredom. Horses can loose condition, they would rather "windsuck" than graze

Some horses wander around looking for something to suck on plays havoc with the paddock infrastructure, also most astro gear.

Electric fences help.

Shooting the horse is probably a bit extreme but works

[stephend]

It's kinda tragic not funny when a horse gets the idea that wind sucking is the thing to do, they almost never get cured even when you reverse the original cause, and they're basically no good for anything ever again. Probably a lot like amateur astronomy.

[iceman (Mike)]

I hope it arrives sooner than anticipated, Al. Can't wait to see progress.

[[1ponders] (Paul)]

Woo Hoo, great news Al. Looking forward to first light.

[h0ughy (David)]

another one with an observatory under way...green with envy Al

[sheeny (Al)]

Originally Posted by gmbfilter

Shooting the horse is probably a bit extreme but works

Yes... well, the horse in question can't be ridden either as it has a "bog spavin" ( not sure of the spelling or even the pronunciation) on a rear hock, but it belongs to one of the girls and she's very attached to it.... I know what I'd do... Nice explanation BTW.

Originally Posted by stephend

It's kinda tragic ... they're basically no good for anything ever again. Probably a lot like amateur astronomy.

Getting close to the bone there!

Originally Posted by iceman

I hope it arrives sooner than anticipated, Al. Can't wait to see progress.

So do I!

Originally Posted by [1ponders]

Woo Hoo, great news Al. Looking forward to first light.

So am I.

Al.

[sheeny (Al)]

Originally Posted by h0ughy

another one with an observatory under way...green with envy Al

Thanks Shrek... uh HOughy!

Al.

[sheeny (Al)]

Just rang Matthew and got an update on delivery of the POD.

Manufacturing is complete. Due to sail on Sept 23. Delivery about 4-5 weeks after that. That means delivery should be during the week prior to IISAC!

Hmmm, maybe I should extend my holidays so I can set it up...

Al.

[Matty P (Matt)]

That's great news Al. You must be really eager to get all setup with your new POD.

Keep us updated.

[sheeny (Al)]

Originally Posted by Matty P

That's great news Al. You must be really eager to get all setup with your new POD.

Keep us updated.

You bet!

Murphy's Law says it will be delayed so it arrives while I'm away at IISAC! ...or it's delivered a day or two before IISAC just to tempt me into staying home to set it up!

Al.

[sheeny (Al)]

Another step closer...

Finished the formwork this morning. The plan is to pour it next Saturday. It'll be a Ready-mix job, I'm not going to mix that much in the mixer without more help than I'll have.

The slab and pier footing are oriented true N-S (within probably +/-5° for compass reading and set up errors). To orient your self the long timbers over hang the formwork on the Northern side.

Al.

[Matty P (Matt)]

Looking good Al,

It is all coming together nicely.

It must have been "Work on your Observatory Day" as I did the same. I concreted the pier in place.

[sheeny (Al)]

Thanks Matt!

Today I cut the reo to save time next weekend and I started putting in the strainer posts to extend the house yard around the obs. I also ran a string line across the pier footing. It seems that even though the level says the footing and the top of the formwork are all level, the footing is about 20mm low compared to the formwork. Obviously, this is less than ideal, but applying a bit of "adaptive engineering" it won't be too big a problem.

It was always my intention to fully grout the pier to the footing. Just bolting it to a footing or slab introduces a flexible connection into the pier, so grout is important... so... I cut a piece of 16mm MDF to fit the bolts and the same size as the footing. Some 4mm spacers underneath will make the board the right height to screed of the slab with expansion jointing around it. I'll strip out the board with the rest of the formwork, and when I fit the pier I'll lay a 20mm thick bed of grout. It should almost look deliberate when I've finished!

Al.

[[1ponders] (Paul)]

Looking forward to seeing the pour finished Al.




BTW I put my floor on today . Photos tomorrow.

[sheeny (Al)]

So am I, Paul! It'll just be a waiting game then till the POD arrives.

Looking forward to seeing your pics. I like watching these projects develop.

Al.