Thinking of building an outdoor pier

[Craig a]

Hello everyone I’m thinking of building an outdoor pier but at as low cost as possible, I’m living  in a rented house so what I build would need to be easily removed if something happens and we move out, I was thinking of the Altair sky pier but at over 600 quid with the mount adapter it’s abit on the expensive side even if I can just be unbolted and moved, my rig is the neq6 with a 10 inch Newtonian riding ontop, I was thinking would a 7x7 inch treated square post used for hanging farm gates off be ok? They are about 40 quid and I could make my own pier top plates and buy the neq6 adapter, if anything happens I can just saw it down at ground level, I also only do imaging from my rig if that helps? 

Edited January 30, 2022 by Craig a

[CCD-Freak]

Check the "Todmorden Pier" threads here on Stargazers Lounge and Cloudy Nights.  Not expensive and very solid.  A car brake rotor make great pier top plates for the Neq6 mount.

Here is my take on the Todmorden pier out in west Texas.

 

[Peter Drew]

You can bolt an EQ6 mount on top of a "Todmorden" mount, no need for steel plates etc, a spacer to spread the load is helpful though.    🙂 

[Craig a]

Thanks for the info but if I can I’d rather use the timber route if it’s doable I seen people on a internet search using timber but most bolt 4 lengths of 4x4 to create a 8x8 pier but was wondering if one 7x7 square post would be sufficient to carry my rig stable enough for imaging, I just don’t trust the concrete block I’ve seen at our local builders especially when a heavy rig is moving round the sky, before now I’ve had concrete block just break in half in my hands on jobs 

[Craig a]

After doing abit more research it seems that wooden piers only work in drier locations in the world as the timber will swell and shrink with the weather and in northwest England we do get quite wet so I may just save up abit longer and just bite the bullet and get the Altair sky pier, i will dig the hole tomorrow and fill with concrete ready for the pier when I press the buy button, I will keep posting updates here on how it’s going 

[david_taurus83]

I think for the short term it would be fine. You just might need to check polar alignment a bit more often. It certainly won't fall apart.

[Swoop1]

I looked into timber when I researched my pier.

I seem to recall the basis behind bolting 4 smaller posts together was that any swelling/ shrinking/ warping would have a lesser effect as it is spread across the 4 as opposed to one large cross section piece.

[malc-c]

The idea of a pier is to be as solid as possible to provide a stable and secure base for the mount.  Thus it either needs to be something like the Altair which can be bolted to a concrete base or slab, or something that is concreted into the ground.  You could draw up a design based on the Altair and see how much a local machine shop would charge to make it, or use the old tried, trusted and cheap method of sinking a length of 6" plastic drain pipe into the ground and fill it  and the hole it sits in with concrete.

However as you are in rented accommodation I would discuss what you want to do and why, and ask permission and gain consent from your landlord first (ideally in writing).  I'm sure if you agree to return the area to the same state as it is in now prior to any work then you should get an agreement if your landlord is reasonable.  

[Rusted]

If you have a scrap metal yard in your area see if they will sell you some 6" steel pipe. Find one with a flange if possible. Very commonplace.
A local engineering shop, or even a garage mechanic/welder, can tack a scrap metal plate on top. Ask who does their welding.
The scrap yard may do the job for you for the price of a pint if you ask nicely. They have cutting torches to shorten pipes too.
Getting it home will need a trailer or van. Or you can carry it in your sports car with a warning flag on the end.

Concrete blocks spread the load because of their very large surface area. The mortar sticks them together over the same, large area.
Concrete blocks, of typical dimensions are immensely stiff compared with smaller section of steel or wood.

I fought with a 6' tall [above ground] 4" steel pipe pier with a heavy flange on both ends. My BIG mistake was desperately avoiding concrete in the hole.
I tried large stones in the very deep hole and even added small stones. Nothing worked and it still shook like a leaf.
I filled the pipe with sand. Nope. Then I filled it with concrete. It as now too heavy to lift without aid and it still shook like leaf when touched!

My present pier is a flour legged pyramid and about 14' high. Built of sawn finish, genuine 100x100/ 4"x4" on a 3m square base.
The feet are bolted to buried, concrete carport foundation blocks with heavy [supplied] brackets buried in self-stabilizing sand & gravel.
The brackets lift your timber off the ground and provide height adjustment. The pyramidal form is stiff. Particularly when clad in 18mm/ 3/4" exterior plywood.
I might be quite unhappy if I inherited a whopping great concrete foundation block in a rented property. Or even in a bought house.
My carport foundation blocks are easily dug up in half an hour and carried away. Along with my 2 story, timber observatory built on these same blocks.
These blocks are dirt cheap in my local big shed discount DIY store. More expensive in builders merchants. The come in different sizes and weights.

Bung four of these blocks in a hole in the ground with a little bit of spacing between them.
Back fill with self stabilizing gravel stamping well with a length of 2x4 timber. [This gravel contains a little clay to bind the particles together]
Build your 4x4  timber pier off the brackets and tighten the galvanized bolts firmly. Clad in exterior plywood if you want "posh."

[Craig a]

Thanks for all your reply’s, my landlord is a good bloke, he doesn’t mind me pouring a concrete block, it’s not massive anyway, the spec Altair state is the hole needs to be 15x15 inch and 3 feet deep, I’m not going down that deep 2.5 feet is enough where I live our ground is like concrete anyway that deep, my landlord let me build a solid block foundation for the aviary that my Harris hawk lives in, he even gave me the foundation block for it as he had some in his garage from an extension he built on his own house 

Edited January 31, 2022 by Craig a

[Rusted]

Then sink your block a couple of inches below ground level if it is on a lawn. To allow turf to grow over the top.

Edited January 31, 2022 by Rusted
typo

[malc-c]

That's one exceptional landlord you have.

Here's some images taken at the time when I was building my observatory.  - 6" plastic pipe concreted into a block approx 1m x 1m x 1m - reinforced with rebar down the middle, and filled with a strong mix of concrete.  Custom made pier head fitted with J shaped threaded rod sunk into the concrete. - Still rock solid after 10 years 

 

[Craig a]

That’s a big hole you dug, mine is nowhere near that size, 15x15inch 2.5ft deep is all I’ve done today, one cubic meter of concrete weighs approximately 2.5 tons there’s no way I need that much 😂

[Rusted]

11 minutes ago, Craig a said:

That’s a big hole you dug, mine is nowhere near that size, 15x15inch 2.5ft deep is all I’ve done today, one cubic meter of concrete weighs approximately 2.5 tons there’s no way I need that much 😂

The surface area of the sides of a buried concrete foundation block must be resisted by the soil when subject to lateral loads
It follows that the weight of the concrete alone is not the final arbiter. 15"x30" is not a very large area in soft soil.
Most of the sideways loading is near the soil surface. That said, a lightly loaded telescope pier is unlikely to suffer much sideways loading.

My 2.2m Ø parabolic satellite dish on a 110mm Ø x 150cm tall pole has a 40x40cm x 1.5m deep hole filled with concrete.
4.5" Ø x 5' tall pipe on  16" x 16" x 50" block in Olde Money. I tapered the hole outwards towards the bottom to resist frost heave.
The wind loading it has suffered would make a complete mockery of almost any telescope pier in amateur hands.

 

[malc-c]

43 minutes ago, Craig a said:

That’s a big hole you dug, mine is nowhere near that size, 15x15inch 2.5ft deep is all I’ve done today, one cubic meter of concrete weighs approximately 2.5 tons there’s no way I need that much 😂

The general thinking in the day was 1cu metre was the "normal" defacto hole when concreting in a pipe.  Much better to go large and over engineer something rather than find you skimped and the base moves, due to soft soil or soil shrinkage in hot weather

[Craig a]

1 hour ago, malc-c said:

The general thinking in the day was 1cu metre was the "normal" defacto hole when concreting in a pipe.  Much better to go large and over engineer something rather than find you skimped and the base moves, due to soft soil or soil shrinkage in hot weather

I understand your reasoning but in northwest England we don’t worry about long hot weather or frost heave 😂, I can count on one hand the amount of frosts we get here in winter in recent years, we just get mild wet winters these days our ground here is a few inches of soil then rock hard clay that’s impossible to dig out without a clay digging attachment to a small jackhammer 🤣, even though I’ve dug the hole I’m beginning to rethink the whole thing to be honest do I really want to spend the time and money on it in a rented property where there’s no guarantee I will still be here in 12 months time even though our landlord is a nice bloke, somthing may come up and we have to move out, I would be gutted after building a permanent pier, I think it was a moment of madness, is it time to call in the straight jacket now? 

[Rusted]

Well, at least you would only own a 300kg monolith instead of the 2.5 tons you feared was overkill.

[Craig a]

Another reason for thinking of a pier was that at the moment my rig is on the skywatcher pillar tripod like this…

https://www.firstlightoptics.com/sky-watcher-mount-accessories/skywatcher-pillar-mount-support-for-heq5-eq6-series-mounts.html

but as my rig is quite heavy there is abit of wobble in the pillar you only have to flick the scope and it’s off on it’s wobble dance, so was going to build the pier to help stop its wobble, I think I need to think of a way of stiffening it up abit now I’ve abandoned the whole build your pier idea I may need to start a new thread in equipment help for ideas to stiffen the pillar mount up abit 

[malc-c]

2 hours ago, Craig a said:

even though I’ve dug the hole I’m beginning to rethink the whole thing to be honest do I really want to spend the time and money on it in a rented property where there’s no guarantee I will still be here in 12 months time even though our landlord is a nice bloke, somthing may come up and we have to move out, I would be gutted after building a permanent pier, I think it was a moment of madness, is it time to call in the straight jacket now? 

it could always be turned into a fancy bird table when you move out

[Craig a]

24 minutes ago, malc-c said:

it could always be turned into a fancy bird table when you move out

The pier would of been a skyshed pier bolted onto the concrete slab and the concrete covered over so if I did move out it would of been as simple as unbolting the pier and taking it with me leaving behind no trace of the slab underneath, I really need to make my mind up ASAP 😂 

im back and forth with should I or shouldn’t I, I hate it when I Carnt make my mind up it drives me bonkers 

[Swoop1]

13 hours ago, Craig a said:

Another reason for thinking of a pier was that at the moment my rig is on the skywatcher pillar tripod like this…

https://www.firstlightoptics.com/sky-watcher-mount-accessories/skywatcher-pillar-mount-support-for-heq5-eq6-series-mounts.html

but as my rig is quite heavy there is abit of wobble in the pillar you only have to flick the scope and it’s off on it’s wobble dance, so was going to build the pier to help stop its wobble, I think I need to think of a way of stiffening it up abit now I’ve abandoned the whole build your pier idea I may need to start a new thread in equipment help for ideas to stiffen the pillar mount up abit 

Have you thought about digging in some decent footpads as a stable base for your tripod?

Something like 3 flowerpots filled with concrete. Another advantage of this is that it helps with speedy alignment of your rig.

[drjolo]

17 hours ago, Craig a said:

but as my rig is quite heavy there is abit of wobble in the pillar you only have to flick the scope and it’s off on it’s wobble dance, so was going to build the pier to help stop its wobble, I think I need to think of a way of stiffening it up abit now I’ve abandoned the whole build your pier idea I may need to start a new thread in equipment help for ideas to stiffen the pillar mount up abit 

I think that may bend at the point I marked red here (all three around of course):

so what you can do is to put some a few mm diameter steel cables (blue lines) with a device to stretch it (sorry, do not know the correct name - see below). Once you stretch all three legs it should be much stiffer.

 

Then you may put this modified tripod on three concrete blocks and that should work much better. 

Edited February 1, 2022 by drjolo

[cajen2]

'Turnbuckle'?

[cajen2]

That's the nautical term....whether it has another name on dry land, I have no idea!

[Rusted]

Turnbuckle is the term used for fencing strainers and pole stays.

I found a picture of my carport foundation blocks.
It might offer inspiration. They sell for about £16 each over here.