Metal or Concrete pier for Dome?

[tooth_dr]

Hi guys

Looking some advice here.  I'm planning of moving my observatory, and so need to make a new pier.

Metal or Concrete, bought or built?  Any particular recommendations.

 

TIA

Adam.

Edited September 25, 2019 by tooth_dr

[JamesF]

Very happy with my "Todmorden" piers made from hollow concrete blocks, and they work out very cheap compared with buying a commercially-produced pier.  They're not desperately attractive though and require a little confidence with DIY.  As mine are inside an observatory I've covered them with ply.

James

[Yawning Angel]

Personally, I found all the off-the-shelf piers where too short for my requirements. What I did buy was the adapter plate suited for my mount, allowing me to swap it in future if I upgrade.

At first I commissioned a custom one from an astro supplier, however, they hashed it up 3 times with long delays between - so I built my own, if only to progress my obs build!

[JSeaman]

I built my own a few years ago (see attached), £120 solid as a rock and is now under my observatory doing it's thing

Pier.pdf

[Moonshane]

my own pier cost about £20 in hardcore and recycled materials and freebies from friends. It's 140cm high and 10" in diameter.

 

[tooth_dr]

Thanks guys.  I have a bought a dome, and although my current pier is concrete and works well, i thought that a metal one might be a bit more fitting for the dome.

At £500 for a pier, and I'm wondernig if I can laser cut, weld and powercoat the same thing for considerably less. 

[x6gas]

I made mine; I've been very happy with it, it doesn't offend the wife too much and it was pretty easy to do.

I poured the base and pier of mine in one piece.  Dug a 75cm cube hole, 3/4 filled with concrete, set a 1.5 meter length of 6" round air conditioning ducting in it filled the tube with concrete and topped off the base.  The tube has 6 x 1m lengths of threaded rod it in with long hex nuts on the top set into the concrete so presents six mounting holes for a top plate.  The hardest part of the job was making a wooden former to ensure the correct orientation of the bolts / keep the threaded rod in the right place.

Edited September 25, 2019 by x6gas

[tooth_dr]

Thanks guys.  Should have been clearer with my opening post.  I've made two concrete piers in the past, but was considering metal this time.  Can it be done for much less than £500 to make it worthwhile?

[x6gas]

6 minutes ago, tooth_dr said:

Thanks guys.  Should have been clearer with my opening post.  I've made two concrete piers in the past, but was considering metal this time.  Can it be done for much less than £500 to make it worthwhile?

My concern with a metal pier is that they ring like a bell.  No problem in an obsy, I presume, where it is protected from the wind and accidental bangs or you can fill it with sand or something else to dampen it.

If you are decided on a metal pier then it all depends on whether you can find someone reasonable to fabricate it up for you.  If you have mates handy with a welder or a friendly garage mechanic then it can be done quite inexpensively but if you go to fabricator I think you'll find you won't save a great deal - but you do get it made to your own spec, of course...  Powder coating it alone would cost £50-75 quid at my local place (though I've no idea how that compares).

[tooth_dr]

Just now, x6gas said:

My concern with a metal pier is that they ring like a bell.  No problem in an obsy, I presume, where it is protected from the wind and accidental bangs or you can fill it with sand or something else to dampen it.

If you are decided on a metal pier then it all depends on whether you can find someone reasonable to fabricate it up for you.  If you have mates handy with a welder or a friendly garage mechanic then it can be done quite inexpensively but if you go to fabricator I think you'll find you won't save a great deal - but you do get it made to your own spec, of course...  Powder coating it alone would cost £50-75 quid at my local place (though I've no idea how that compares).

Defintiely looking to hear feedback on metal piers, not sure I would want to fill it with sand or anything.  I was thinking I can run wiring up the middle to tidy up the installation!  Maybe I should amend the opening post!

[tooth_dr]

Title amended to reflect better what I am actually trying to find out.

[Davey-T]

11 minutes ago, tooth_dr said:

Thanks guys.  Should have been clearer with my opening post.  I've made two concrete piers in the past, but was considering metal this time.  Can it be done for much less than £500 to make it worthwhile?

If you're capable and equipped with the right tools you can easily knock one up for less than £200.00 and even less using second hand steel.

Made this one for less than £200.00 only Hammerited, don't see any point in paying out for powder coating.

Dave

 

[tooth_dr]

1 minute ago, Davey-T said:

If you're capable and equipped with the right tools you can easily knock one up for less than £200.00 and even less using second hand steel.

Made this one for less than £200.00 only Hammerited, don't see any point in paying out for powder coating.

Dave

 

That looks robust   and avoids using a tube.

What thickness of steel?  Is 10mm too thick?

 

[JSeaman]

Mine was £120 with all materials. The metal was about £30 and is readily available. You don't have to be able to weld but it does help

Mine is half filled with cement and doesn't ring at all, I'd definitely do it again that way

[tooth_dr]

3 minutes ago, JSeaman said:

Mine was £120 with all materials. The metal was about £30 and is readily available. You don't have to be able to weld but it does help

Mine is half filled with cement and doesn't ring at all, I'd definitely do it again that way

Bolted with 4 bolts into a base?  Is the concrete a necessity?

[Davey-T]

4 minutes ago, tooth_dr said:

That looks robust   and avoids using a tube.

What thickness of steel?  Is 10mm too thick?

Tube is 5mm and flat plate 10mm, it sort of evolved unplanned from some bits I already had which accounts for the shape 😂

Dave

[tooth_dr]

Just now, Davey-T said:

Tube is 5mm and flat plate 10mm, it sort of evolved unplanned from some bits I already had which accounts for the shape 😂

Dave

No I mean it looks functional and awesome.

I have 10mm plates made, so 5mm steel for the rest of it is probabaly more than adequate.

[Star101]

4 minutes ago, JSeaman said:

Mine was £120 with all materials. The metal was about £30 and is readily available. You don't have to be able to weld but it does help

Mine is half filled with cement and doesn't ring at all, I'd definitely do it again that way

Same here. A metal tube of about 10" diameter filled with cement, cemented in the ground. Solid!!  The plate on top has four long bolts sunk into the concrete inside the metal tube to hold the plate in situ. That plate has four more bolts connected to the top plate for leveling. Where the mount sits atop that.

If I had to do it again, I would just go with a concrete pier with some rods inserted to give it strength. Box it in to make it look neat. Much cheaper than metal tubing. 

[dave_galera]

+1 for concrete pier concreted in the ground with 12mm studding embedded in the concrete.

[JSeaman]

12 minutes ago, tooth_dr said:

Bolted with 4 bolts into a base?  Is the concrete a necessity?

No bolts, post was sunk into postcrete, set in seconds and absolutely solid. I would definitely do that again too and it was one of my first goes at using it, cheap and easy and very effective

[upahill]

Could be worth asking a local welding company to knock one up for you. There is a guy near our storage unit who has a load of 8" steel box going rusty in his yard - keep meaning to ask him how much he would charge to chop it up and add some plates.

I imagine it would be significantly cheaper than a commercial one (note cheaper, not necessarily better )

[Anthonyexmouth]

heres my concrete one . 600mm cube under the deck and rebar up through the duct. all cabling internal. I figured i needed a concrete block whatever i was doing so easier to knock up a little more and make the pier as one big 1 ton lump. all in i think it came to £150ish with the concrete, stainless fixings, plate and duct

 

[Star101]

1 hour ago, Anthonyexmouth said:

heres my concrete one . 600mm cube under the deck and rebar up through the duct. all cabling internal. I figured i needed a concrete block whatever i was doing so easier to knock up a little more and make the pier as one big 1 ton lump. all in i think it came to £150ish with the concrete, stainless fixings, plate and duct

 

Very nice Anthony. I like the simplicity. very cool 

[Anthonyexmouth]

22 minutes ago, Star101 said:

Very nice Anthony. I like the simplicity. very cool 

certainly future proofed by being a 300mm wide concrete pier, not sure i could ever afford a telescope to overload it. 

[Jkulin]

Adam, if you want the plans for my metal pier, then I can send them to you..