It started with a hole... never thought it would come to this

[Pompey Monkey]

I am going to make a pier for my newly acquired AZ-EQ6 because, even after a short return to hands-on astronomy after several* years absence, I am getting fed-up with the set-up procedure.

I already knew the best position in my garden, so I have started digging a hole for my concrete tether: 1m X 1m X 0.9m deep:

However, I have already seen a Kever 6' by 4' plastic shed on Ebay, for buyer collection nearby, and I have put a bid on it. I don't like losing Ebay auctions, so I am looking to create a roll-off obsy over the summer. This seems to be the best place to blog/share my catastrophes/experiences and get advice that I've found. So let the journey begin!

Feel free to tear me a new one if you like. I'm off to smoke a kipper before breakfast.

* More than I would like to divulge.

** Apologies to Errol Brown

Edit: 100th post! Yaay!

[Pompey Monkey]

Day 2:

I didn't win the ebay auction because the wifi in Wetherspoons was not working!  . It was for a shed just like the one in Mikes thread: http://stargazerslounge.com/topic/234625-mikes-roll-away-shed-observatory/

Anyway, more digging was done and I'm down to about 30" deep, so not too much more to go.

However, the hardcore below the old concrete (which was for a greenhouse I think) was more like a boulder field and the net result is that there is little or no support under the surround. I will have to shutter it and back fill with more concrete, but I'm not sure whether to do this before or after filling the pier hole. I have some time to think it over - anyone have any suggestions?

You can see the "boulders" in one of my pictures.

[Beulah]

If it were my garden I'd take out that concrete altogether, level, then reconcrete. If you don't do it, later you will wish you had. There's already a sign of cracking at the front part of the concrete base. Probably was OK when it was first built, but the work you have done has probably disturbed the scalpings layer, hence the void.

At least you'll be able to take a good swing into that hole with a mattock/pickaxe, instead of worrying about damaging the concrete.

[Pompey Monkey]

If it were my garden I'd take out that concrete altogether, level, then reconcrete. If you don't do it, later, you will wish you had. There's already a sign of cracking at the front part of the concrete base. Probably was OK when it was first built, but the work you have done has probably disturbed the scalpings layer, hence the void.

At least you'll be able to take a good swing into that hole with a mattock/pickaxe, instead of worrying about damaging the concrete.

I knew this was coming! lol

I might be moving house in the next year or so, so am trying to keep the expense/effort to a minimum. I can just about dispose of the current rubble and soil in my car. If I dig up the whole slab (as I really should, I know) I'll need a skip. There is nowhere to put one outside my house, I have no rear access and it is a 40 yard trip from the site just to the back of my house...Then factor in the wheelbarrow runs through the living room, stopping the cat gettiing out the front door into the sometimes busy street, waiting to cross the road to wherever a skip would end up...you get the idea...

Removing he whole slab would turn a medium summer project into a major undertaking...

I was hoping to get a good solid pier with some decking supported on the surrounding structure, just to last me the year or so.

[Pompey Monkey]

For anyone who's interested, here is an un-annotated 3D pdf of my pier design. It's not finalised, but I find that CAD really helps me iron out potential issues before throwing money at a project

pier.pdf

[RichM63]

Why not just dig another hole and bury the rubble?

Best of luck.

[Pompey Monkey]

Why not just dig another hole and bury the rubble?

Best of luck.

I could always build a rockery. Or should that be shrubbery?

I've given it some thought and the old greenhouse plinth will be perfectly adequate to support a bit of decking. As long as I isolate the old concrete and deck from my pier, I'll be fine.

The real problem will be camouflaging the pier when prospective house purchasers have a viewing

[Beulah]

I think you could be right there with the decking, as long as it's isolated to prevent vibration.

Oh, those Keter sheds...they are great, rain proof, but not completely bug proof...had to knock out a wasps' nest yesterday!

[Fish]

Ooooo another plastic pig, if you are doing a roll off roof I would make 6x6 the smallest size 6x4 would make a great roll off.

I spray with an aerosol insect killer every 6 weeks or so and it keeps everything out (so far) .

[wxsatuser]

You don't need a massive hole.

Mine is just 600mm cubed.......the pier is just a length of 8inch drain pipe filled with concrete.

Obsy is just four 4inch fence posts with a deck between on concrete footings.

Decking under construction.

[Pompey Monkey]

You don't need a massive hole.

Mine is just 600mm cubed.......the pier is just a length of 8inch drain pipe filled with concrete.

Obsy is just four 4inch fence posts with a deck between on concrete footings.

Decking under construction.

Well, the hole is dug - I'll have to fill it with something. It might as well be concrete!

The shed type and size is not finalised, but I do like the reduced maintenance aspect of the "plastic pig".

[Pompey Monkey]

Well I finally am taking a week off work

Today I have been fabricating the pier/mount interface. I found a pair of MCD293 brake discs for £17.99 that have a hole 66 mm in diameter - this gives about 1/2 mm clearance around my AZ-EQ6 base

I bolted the brake disc, 10 mm ally disc (that goes between the brake disc and concrete to give the mount bolt a purchase) and the plywood bolt jig together while I drilled the holes so that they would align properly.

My rebar arrived last week and I am hoping to pour the concrete next weekend.

[wxsatuser]

Coming along nicely.

[Garethr]

I love watching these builds "develop"

Mount plates looking good

[happy-kat]

Garden decking is very popular for rodents to live under and flipping slippery in winter

[Physopto]

Well I finally am taking a week off work

Today I have been fabricating the pier/mount interface. I found a pair of MCD293 brake discs for £17.99 that have a hole 66 mm in diameter - this gives about 1/2 mm clearance around my AZ-EQ6 base

I bolted the brake disc, 10 mm ally disc (that goes between the brake disc and concrete to give the mount bolt a purchase) and the plywood bolt jig together while I drilled the holes so that they would align properly.

My rebar arrived last week and I am hoping to pour the concrete next weekend.

That brake disc is a great idea. Much cheaper than buying a steel flange. It also ahs good vibration dampening ability due to being made of cast iron. I looked all over for flanges etc and they were stupid prices.

Derek

[Pompey Monkey]

Coming along nicely.

Thanks

I love watching these builds "develop"

Mount plates looking good

Keep watching, because there's no going back now!

Garden decking is very popular for rodents to live under and flipping slippery in winter

Noted. I'll make sure that there's manoeuvring space for my cat in there too!

That brake disc is a great idea. Much cheaper than buying a steel flange. It also ahs good vibration dampening ability due to being made of cast iron. I looked all over for flanges etc and they were stupid prices.

Derek

Didn't know about the vibration dampening properties and I have to confess that the idea to use one came from some build threads right here on SGL!

Well, I've given up finished digging the hole at 90 cm deep - there's only so much back pain that I can tolerate and the received wisdom is that this will be deep enough.

Now I have to get the spoil down the tip. The tough supermarket "bags for life" are ideal for this: 6-8 in the boot of the car every work-day should clear it in about two to three weeks!

I have also ordered the cement (300 kg) and ballast (1600 kg) in 25 kg plastic bags (as it will surely rain at some point) which are due to arrive tomorrow or Thursday. I am getting some friends in to help move that lot the 60 metres from the front, through the house and down the garden... Like I said before, I have no side or rear access to my garden    I have, however been offered the use of a cement mixer for the job Yaaaay!!!

I am also going to chop back the top layer of old concrete to about 150 mm from the edge of the plinth, shutter it off and pour some more concrete to make the edges good (maintaining a suitable gap, of course!).

I also have to continue fettling the pier tube and head to be ready in time for the weekend.

Time for a beer now

[Physopto]

It's a pity you have ordered up all the cement already. You could have saved yourself a fair bit of work and time by casting the pier support as a pyramid, ( with flat top). Then back filled with some of the spoil. Uses less cement and you don't have to get rid of all the extra spoil.

Hope all goes well, it's a lot of work I know. Did the same several years ago. I never got past this stage as I'm moving.

Derek

And no I didn't follow my own advice, hadn't thought of it then!

[Pompey Monkey]

It's a pity you have ordered up all the cement already. You could have saved yourself a fair bit of work and time by casting the pier support as a pyramid, ( with flat top). Then back filled with some of the spoil. Uses less cement and you don't have to get rid of all the extra spoil.

Hope all goes well, it's a lot of work I know. Did the same several years ago. I never got past this stage as I'm moving.

Derek

And no I didn't follow my own advice, hadn't thought of it then!

As the great Homer* would say: D'OH!

I will bear this in mind next time (for there will be a Mk.2 at some stage). At least I have already planned to use the old ballast in the pit!

I am now in an indecision as to build a roll-off shed, a roll-off roof, or a full obsy... This consideration directly affects the height of my pier, so I need to decide very soon, or put off the pour! Gaaahhhhh!

*Simpson, not he of the Ilyad.

[Physopto]

As the great Homer* would say: D'OH!

I will bear this in mind next time (for there will be a Mk.2 at some stage). At least I have already planned to use the old ballast in the pit!

I am now in an indecision as to build a roll-off shed, a roll-off roof, or a full obsy... This consideration directly affects the height of my pier, so I need to decide very soon, or put off the pour! Gaaahhhhh!

*Simpson, not he of the Ilyad.

You could always just do as I did leave a flat surface to later drill into and bond in bolts to suit a steel pier. It would give you time to decide.

You can always remove the pier and take it with you when you move house.

Derek

[Pompey Monkey]

Well, I decided on a roll-off shed: If the weather is nice we can set-up on the bench near the telescope and enjoy the (somewhat light polluted) sky. If It's freezing we will operate remotely via wifi (I will set up a dedicated link from the house with a 14 dBi antenna and router).

Now the progress:

The hole is finished and shuttered, cement and ballast delivered, the mount interface is made, all is level and aligned north/south and we are good and ready to mix and pour tomorrow!

And I had a visit from the very friendly neighbours cat while I was working today

Sorry for the brevity of the post - this is hard work!!! I'll try to answer any questions though

Edit: PS I have added some rebar to the pillar, but it's not in the pictures.

[wxsatuser]

The ballast is in..........now we know you mean it.

Good luck with the pour.

[Pompey Monkey]

Well, now I know how to mix concrete! 350 kg of cement, 1400 kg of aggregate and another 100 kg or so of lumps previously removed from the hole!

Not quite as neat as I hopped, but it was our first time and it will all be covered up eventually. And it is just about dead level at the top

And no, I'm not in any of the pictures

[richyrich_one]

Well done, I think that once the pier is done it's all downhill. Not speaking from experience mind you I just really hope so. 

Hopefully my pour is this afternoon as it's cooler. 

[Pompey Monkey]

Well done, I think that once the pier is done it's all downhill. Not speaking from experience mind you I just really hope so. 

Hopefully my pour is this afternoon as it's cooler. 

I've been going downhill for years

Good luck with your pour. Just remember it's there to give any future owners of your house something to remember you by!