Pier Base Setup

[multiweb (Marc)]

Some serious earth work and machinery here. The scope will be on rock solid grounds.

[CDKPhil]

Originally Posted by multiweb

Some serious earth work and machinery here. The scope will be on rock solid grounds.

Having a tractor has made my job a lot easier, thats for sure.
But I still had to get in the hole with a jackhammer and a shovel.
I don't think when I am finished it will have the great colourful paint job as your pier Marc.

Cheers
Phil

[CDKPhil]

I have back filled the pier site and also levelled the pier footing. I used a levelling compound which has worked very well. It has given me a very flat surface to ground the pier base. You can see in the photo I managed to get a steel ruler to stand on its edge, there are no undulations in the surface.

The pier has been ordered from Software Bisque, hopefully it will arrive next week.

The next step will be, to make the platform.

cheers
Phil

[frolinmod]

Originally Posted by CDKPhil

I have back filled the pier site and also levelled the pier footing. I used a levelling compound which has worked very well. It has given me a very flat surface to ground the pier base. You can see in the photo I managed to get a steel ruler to stand on its edge, there are no undulations in the surface.

The pier has been ordered from Software Bisque, hopefully it will arrive next week.

Excellent Phil.

As I understand it, the problem with the steel pier is that the bottom acts like a drum. The steel base needs to have firm contact with the concrete footing with no high or low points. A smooth flat concrete footing works best. Torquing the pier firmly to the footing is derigueur.

The last thing you ever want to do is to suspend the pier up the the air on ("leveling") bolts and nuts.

[Marke (Mark)]

How did you lvl the top Phil it looks pretty smooth.

[mithrandir (Andrew)]

Originally Posted by Marke

How did you lvl the top Phil it looks pretty smooth.

Leveling compound. Mark, my brother works for Ardex and that links to their leveling product list. He also lives in Castle Hill if you want some professional comments.

[Marke (Mark)]

Thanks for that info Andrew I will keep that in mind when finishing off the pier base.

[CDKPhil]

Originally Posted by frolinmod

Excellent Phil.

As I understand it, the problem with the steel pier is that the bottom acts like a drum. The steel base needs to have firm contact with the concrete footing with no high or low points. A smooth flat concrete footing works best. Torquing the pier firmly to the footing is derigueur.

The last thing you ever want to do is to suspend the pier up the the air on ("leveling") bolts and nuts.

Thanks
Thats how I under stand it. From what I have been reading it is best to get the
footing level and smooth. I have read a lot of bad things about levelling bolts.
I guess if you look at a pier it has a very ridged structure. By placing three or four bolts on top or the bottom compromises the strength of the pier. I would imagine that having bolts would introduce all sorts of movement.
I can see the attraction of levelling bolts but it is not that hard to get a level surface. It does take a bit of time but it is worth the effort.

Originally Posted by Marke

How did you lvl the top Phil it looks pretty smooth.

What Andrew has said. I used a levelling compound by Ardex. I ended up putting three layers on to achieve the result that I wanted. I put some form work around the top of the footing, primed the concrete and poured the compound onto the top of the footing. Using a trow I pushed the compound around till it had an even thickness and then let it set. It only takes about ten minutes to go off so you need to be quick. It has given a very flat surface.
There are some epoxy base levelling compounds available and they give better results than the cement base products. I did not use the epoxy because the Ardex product achieved a very good result.


Cheers
Phil

[Marke (Mark)]

Thanks Phil my pier should be ready next week , I will see how well I can level the concrete and may be try the Ardex although it will have a lvling plate anyway.

[CDKPhil]

Originally Posted by brumby

Would it be best to use a cement pier or build a steel one (for stability?)

Hi David,
From what I have been reading a steel pier will have a lot less flex than a concrete one of the same diameter. If you read this thread http://www.iceinspace.com.au/forum/s...ad.php?t=86411there is a post by AL (sheeny) and he explains the difference with concrete and steel.

Originally Posted by Marke

Thanks Phil my pier should be ready next week , I will see how well I can level the concrete and may be try the Ardex although it will have a lvling plate anyway.

NP Mark
Remember the smoother and flatter the surface the better the pier will be grounded.
I would like to see some photos when you are done.

Cheers

Phil

[Marke (Mark)]

Sure thing I was going to use grout under it but your solution may be just as good I think and its pretty damn heavy

[jenchris (Jennifer)]

put the baseplate onthe concrete before it sets! then you have a matched base. It won't need much to make it 100% contact face then. Epoxy mixed with fibre with a cling film separator (or you'll never get it off again!) and pull it down til the epoxy squeezes out the sides - 100% contact -

[Marke (Mark)]

Good idea Jen I was thinking something like that only it weighs about 70kg
I may need to wait till it sets a bit

[CDKPhil]

Here is the latest. This might be a bit obsessive or pedantic. I have used a piece of 25mm thick aluminium as my contact surface for the base of the pier.
Rather than have the pier onto concrete which is level and flat I thought I would try to use a metal contact surface, this is far smother and flatter than the levelling compound. And if I wanted to get really pedantic I could have the surface machined.
I have used 16mm stainless steel Ramset chem studs to hold the aluminium plate down. I will then tap 16mm holes for the pier. I will anodise the aluminium to protect it from oxidisation.
I am calling it a pier to concrete interface.

Cheers
Phil

[Marke (Mark)]

Phil I dont think you are trying hard enough I am using 20mm steel plate
top and bottom with 20mm bolts but I am sure yours will look prettier :p

[CDKPhil]

Originally Posted by Marke

Phil I dont think you are trying hard enough I am using 20mm steel plate
top and bottom with 20mm bolts but I am sure yours will look prettier :p

I have got bolt envy now

[Marke (Mark)]

Originally Posted by CDKPhil

I have got bolt envy now

lol thats a new one

[jenchris (Jennifer)]

Mine's a pretty blue and isn't bolted at all, it's embedded 750mm into the concrete. There's 4 inch holes spaced around it in the concrete through which reo is introduced and the whole thing is filled to the top plate (15mm steel) with reinforced concrete.

Vibrations - nil - though the fork on the OTA is still a problem.

I noticed that previously the adjustment of the focus would be sufficient to disturb the system when x10 on the live view. I'd have to wait for a few seconds for it to reduce.
Now, I can grab and adjust and it stays pretty much still - any vibe is gone in a second or two. I'm happy with that. I know it could be better, but the fork is causing most of it I think.

[CDKPhil]

Originally Posted by jenchris

Mine's a pretty blue and isn't bolted at all, it's embedded 750mm into the concrete. There's 4 inch holes spaced around it in the concrete through which reo is introduced and the whole thing is filled to the top plate (15mm steel) with reinforced concrete.

Vibrations - nil - though the fork on the OTA is still a problem.

I noticed that previously the adjustment of the focus would be sufficient to disturb the system when x10 on the live view. I'd have to wait for a few seconds for it to reduce.
Now, I can grab and adjust and it stays pretty much still - any vibe is gone in a second or two. I'm happy with that. I know it could be better, but the fork is causing most of it I think.

Nice Job.

I take it you have reo welded to the bottom side of the top plate? or do the levelling bolts go down 750mm into the concrete?

May be the levelling bolts are introducing some movement?

Cheers
Phil

[jenchris (Jennifer)]

No there's a central J bolt that runs down 200mm, the plate was set in place when the concrete was still plastic. The central bolt tensions the concrete onto the plate there is no play at all.
Basically the only thing that can move is the fork and the leveling plate bolts - which are protruding a little more than they need - I can take them down quite a lot now that the angles are established and the initial drift alignment is done.