Pier Construction Advice

[zedds]

A second way to do things is to put the plastic pipe all the way to the bottom of the hole you have dug BUT after making several large holes in the wall of the pipe below ground level - thus when the concrete is poured the concrete can freely flow between the inside and outside of the pipe and will set "holding" the pipe in place.

Hello Rich. How Bizibilder advised above is how i did mine.

I`ve put up a few pics to show how i did it. I hope they are of help to you. I used 160mm HPPE high pressure water pipe for the pier.

1st pic shows all the reinforcing in place.

2nd shows pipe in place with holes drilled at the bottom. Only one is visible in this pic but there were three at the time. I actually put four more in.

3rd shows pipe and bracing.

4th shows finished pier with the template with rods in place lined up north.

[MartinB]

With regard to 6" vs 8". Most people seem to go for 8". I chose a 6" Episilon aluminium pier for my dome observatory. The dome is very sheltered and there really aren't any sideways pressures on the rig. The narrower diameter of the 6" pier gives a tad more tracking time beyond the meridian. If you are in a more exposed situation then 8" may be a better bet but, in reality, if you have enough wind to deflect a 6" pier significantly it will also be doing bad things to the rest of your set up and it is probably time to pack in the imaging session!

You will hear all sorts about "ringing". At first I left my pier hollow. Then filled it with sand and oil. I noticed no difference at all except that I ended up with oil seeping out through the bottom of my pier!

[ribuck]

Thanks all,

I feel a lot happier about the construction method now. I think i'll go with some 8" plastic and have it set in the ground with holes in the pipe at the bottom.

Now to try and figure out how many bags of sand, stone and cement i need to fill a 8" pier

Rich.

[Bizibilder]

Try this:

Concrete & ballast volume mixing concrete calculator - cubic metre quantity mixing calculator

And use the combined sharp sand/gravel amount to give you the amount of ballast you need.

ADD 20% to the total!!!!! You can always find a use for a bit extra but you can do nothing if you buy yourself "short". Bags of ballast are cheap! Hope this helps.

Edited June 26, 2011 by Bizibilder

[Freff]

This is my effort. I did contemplated going for the concrete method but quickly dismissed it for the steel option. http://stargazerslounge.com/diy-observatories/144553-build-begins-part-1-pier.html

With the steel option I could adapt it at a later date if needs be. Also, I was mine to take with me if I moved or changed locations.

HTH

[Gina]

The steel option is fine if you have access to the raw material and can weld/cut etc. or have a tame steel fabricator on hand. OR can afford one of the ready made steel piers.

[Freff]

The steel option is fine if you have access to the raw material and can weld/cut etc. or have a tame steel fabricator on hand. OR can afford one of the ready made steel piers.

Gina of course you are dead right. I was fortunate and got my materials cheap. A couple of members have asked me to quote a price to make theirs for them.

I can see after costing up the materials and labour where all the money goes. Even if I could get the materials relatively cheap and just charged reasonable rates, the costs are in the hundred of pounds for basic minimal sized piers.

I asked a pipe fitter welder friend of mine to give me the cost of a pier based on my specs. I nearly fell over when he said >£800, without the machined mount adapter.

His reasoning was that he would not have time to source materials from scrap yards etc.. it would need to be ordered cut to size and would have to charge the hourly rate of a pro welder.

The only difference I think between the two methods is circumstances.

BTW your build is looking better each post. I can't wait to start mine.

[Tim]

Try getting in touch with Richie Jarvis Rich, I think he was doing something with piers a little while ago.

[laser_jock99]

Would love to know what diameter piers people are using for imaging ?

Also there any people on here that manufacture pier adapter plates ?

Rich.

I'm using an 8" dia steel pier 1.8m high for my obsy. It cost £100 from my local steel stockist/fabricator - but it's mighty strong & really heavy >80kg. The EQ6 adaptor I had made as a favour by a local engineering shop (we give them around £20,000 worth of work a month!).

[daslolo]

On 24/06/2011 at 12:04, Bizibilder said:

The advantage of a bolted down steel pier is that you can move/remove/modify it quite easily. Concrete is pretty much permanent. In terms of "strength" there is not much between the two if properly built.

My own steel pier was made (welded) by the local steel fabricator - I just drilled the holes and shaped the plates (as I have access to machine tools). All the steel (offcuts) and welding came in at around £70 if I remember correctly.

70 GBP!? damn that's cheap, care to show photos and dimensions?

[MarkAR]

OMG, this thread is 9 years old !

[laser_jock99]

On 20/05/2020 at 01:16, MarkAR said:

OMG, this thread is 9 years old !

....and still relevant! And my pier is still there!!!