Advice Needed Pole Query

[Offtensive]

I am going to be digging up the garden over the next few days, and I am tempted to install a pole for a new dish whilst I am at it. I will either be install 2 Zone 2 or 80cm dishes, or a 1.1m dish instead. The dish (or dishes) will be fixed, with a 4 to 5 Lnbs total.

The dishes will be circa 5 feet above the ground and about 6 to 12 inches in front of the garden fence.

Would an aluminium pole and one or two bags of postcrete be suitable for this? My main concerns are if the aluminium pole shatters in the wind and the weight of the dish causing the pole to eventually move.

My other option is to use a fence post. I assume this would be stronger than the aluminium pole, but if this could eventually move with the weight.

A scaffold pole may be an option instead of an aluminium pole, but I will need to see if I can source one locally big enough. Also, I assume I would need to use more postcrete with this given the weight of the pole?

Thanks

 

[moonbase]

I am going to be digging up the garden over the next few days, and I am tempted to install a pole for a new dish whilst I am at it. I will either be install 2 Zone 2 or 80cm dishes, or a 1.1m dish instead. The dish (or dishes) will be fixed, with a 4 to 5 Lnbs total.

The dishes will be circa 5 feet above the ground and about 6 to 12 inches in front of the garden fence.

Would an aluminium pole and one or two bags of postcrete be suitable for this? My main concerns are if the aluminium pole shatters in the wind and the weight of the dish causing the pole to eventually move.

My other option is to use a fence post. I assume this would be stronger than the aluminium pole, but if this could eventually move with the weight.

A scaffold pole may be an option instead of an aluminium pole, but I will need to see if I can source one locally big enough. Also, I assume I would need to use more postcrete with this given the weight of the pole?

Thanks

Postcrete is an expensive way of anchoring a pole in the ground, is there any reason why you are using postcrete rather than making up a sand/ballast and cement mix from bags?
Once you have worked out the depth of the pole in the ground and the wind load on the dishes you can get a rough idea of the volume of anchorage required for the pole.

The rough guideline is for one third of the pole length in the ground and two thirds above the ground.
Some "Pole Men" also introduce anti spin measures to prevent the pole spinning in the ground.

The greater the wall thickness of the pole the less prone it should be to flexing.
Out of choice I would personally go for steel rather than aluminium.
However, you are only sticking small dishes on the pole so there aint gonna be that much wind load.

Have a sniff on eBay for scaffold poles locally, there gotta be shed loads of 'em surely?
Alternatively, phone around a few local scaffolders or walk onto a job where they are putting up or removing scaffolding and wave a tenner at one of them.

 

[Terryl]

Well a piece of inch and a half or two inch galvanized plumbing pipe should do the job, you would need about 2 to 3 feet below ground, (depending on your local soil conditions) and put the end you cut in the ground, that way you can use a pipe cap to seal the top end off. a 3/8 inch bolt through the bottom end would keep it from twisting in the wind, and dont dig a round hols, a square one will help with keeping it from twisting.

And a sack of quickrete here state side is only $5 US, I dont know how much over at your end, but dont use fence post mix, it's not going to be strong enough to hold up to the shaking around in the wind.

 

[statalite]

Maybe think about if you are going to want to later change or add a bigger dish?
For example I was told on my thread that for a Trial TD 110 dish and a motor would require a 3 inch steel pipe as the weight I was proposing would have certainly flexed a 2 inch steel pipe.

 

[Offtensive]

I was thinking of using postcrete mainly due to the ease. As I write this, I remember that I have a mixer lying in the shed, so the sand/ballast and cement mix should be doable for me.

I think my neighbour is supposed to be getting an extension over the next few weeks, so I may be able to grab some scaffold poles from them. For the anti spin measure, what's the best way to get a hole in a scaffold pole safely?

 

[Manikm909]

I was thinking of using postcrete mainly due to the ease. As I write this, I remember that I have a mixer lying in the shed, so the sand/ballast and cement mix should be doable for me.

I think my neighbour is supposed to be getting an extension over the next few weeks, so I may be able to grab some scaffold poles from them. For the anti spin measure, what's the best way to get a hole in a scaffold pole safely?

cobalt drill bit and drill

small hole first - then go bigger....

 

[moonbase]

I was thinking of using postcrete mainly due to the ease. As I write this, I remember that I have a mixer lying in the shed, so the sand/ballast and cement mix should be doable for me.

I think my neighbour is supposed to be getting an extension over the next few weeks, so I may be able to grab some scaffold poles from them. For the anti spin measure, what's the best way to get a hole in a scaffold pole safely?

If using a hand held drill you could use a centre punch on the pole to give a surface guide to stop the drill bit wandering or some thick tape?
Alternatively, bash it with a club hammer to flatten the pole a little bit and there is less chance of the bit wandering.

As the pole section with the anti spin bolt(s) is going below ground level the cosmetic appearance is irrelevant.

If you know anyone who has a welding machine and will do mates rates you could weld a couple of steel flaps on to the pole section that is to go below ground and avoid the drilling.

 

[Channel Hopper]

Postcret around this region is under £6 a 20kg bag.

 

[moonbase]

B&Q prices
Ballast = £2.78 for 25kg
Cement = £5.18 for 25kg
Postcrete = £5.90 for 20kg

Using a 4:1 mix of ballast and cement, raw material weight is 125kg for £16.30p
Postcrete at £5.90p works out at £36.87p for the same raw material weight, more than double the price of mixing up from ballast and cement.

 

[Offtensive]

I have done some prelim analysis using the information from here

Just Sharing This - My Channel Master 1.8 project.

how deep would i need to accommodate such a weighty beast...? 'ere, cop for this table attached below. The table presents the wind load and anchorage parameters for a 1.8m dish. You can "shape your hole" to provide sufficient depth and with enough anchorage :eek: Calculations are...

www.satellites.co.uk

Here are my rough, pre-coffee calculations from this morning

For a Zone 1 dish:
Area circa 2.02 cu ft (54 * 43 * pi/4 / 900)
Wind load for 80mph wind: 33.2lb (2.02 * 16.38)
Concrete required: 0.22 cu ft (33.2 / 175 * 1.17)

So if my pole is 4 feet above ground, 2 feet below ground, implies I would need a hole roughly 4" x 4" x 2 ft


For a Zone 2 dish:
Area circa 3.71 cu ft (76 * 56 * pi/4 / 900)
Wind load for 80mph wind: 60.8lb (3.71 * 16.38)
Concrete required: 0.40 cu ft (33.2 / 175 * 1.17)

So if my pole is 4 feet above ground, 2 feet below ground, implies I would need a hole roughly 5.5" x 5.5" x 2 ft



At the other extreme, for a Toroidal T90 dish or a similar size 1m dish

Area circa 11 cu ft
Wind load for 80mph wind: 180lb
Concrete required: 1.2 cu ft (180 / 175 * 1.17)

Again, pole 4 ft above ground, 2ft below ground, implies a hole of 9" x 9" x 2ft

But for something like a toroidal dish, would I need to consider other factors as the dish is front heavy

 

[moonbase]

If you are putting a 2" diameter pole in the ground it will take up 2" of a Zone 1 dish 4" x 4" hole and you will be left with a 2ft depth of concrete that is 1" thick and a little over around the pole.
You are not seriously considering this are you?

 

[Offtensive]

Cr***

I forgot to account for the area of the pole

Is it better to pour the concrete in first, so that the concrete is in the pole too? Or do I just want to keep the concrete outside the pole only?

 

[Terryl]

What is your soil like where your going to put the dish??? Sandy loam, clay, soft dirt, rocky, very hard?

This would determine the depth and size of the hole needed and if you need a soil cap around it.

A soil cap keeps the dish and post from moving in a strong wind with rain drenched soil at the base, a soft soil with lots of rain could need a soil cap (part of the concrete needed for the post) that could be 2 to 4 feet square, but again this would be determined by the type of soil at that location.

And it's best to put the pole in the hole first, this way you can brace it up to be truly vertical left to right/front to back, some 1x2's, ground stakes and C clamps can be used to do this, the more vertical the pole, the less tracking problems you will have, also your local electrical codes may require a ground rod, this could be put into the base and stick up a few inches to connect a ground wire to it.

 

[Channel Hopper]

Cr***

I forgot to account for the area of the pole

Is it better to pour the concrete in first, so that the concrete is in the pole too? Or do I just want to keep the concrete outside the pole only?

You can fill the pole from the top after the base has set.

 

[Offtensive]

What is your soil like where your going to put the dish??? Sandy loam, clay, soft dirt, rocky, very hard?

The soil is medium ish I would say. Soft on the surface, but rocky after the first 8 inches.

also your local electrical codes may require a ground rod, this could be put into the base and stick up a few inches to connect a ground wire to it.

Thanks, that never occurred to me - I will have a look into that.

 

[Offtensive]

If I go with a pole, the difficultly I will have is ensuring that it remains at 90 degrees. I don't have much to clamp it too.

Do anyone have any views on the following mount or something similar?

Blake UK Tripod Satellite Mount - 60mm Dia Tube x 1m High @ TradeWorks

Blake UK Tripod Satellite Mount - 60mm Diameter Tube x 1m High SAT/3O(60) online from TradeWorks. Unsure? Speak to our technical team on 0191 487 1292

www.trade-works.co.uk

It seems to be adjustable, to help ensure that it is at 90 degrees.

https://www.blake-uk.com/productdownload/render/SAT3O/PA2011-8030-01_(SAT_3O_P).pdf

 

[gap30]

Dont make the mistake I made when I installed my pole for my 1.5m gibby I really went to town and wedged it in with bricks and it was bang on level

Somehow during the curing process it moved ever so slightly not much but enough to give me some 'slight' issues

Make sure you secure the pole at the top end good luck

 

[ozumo]

For fixed dishes the plumbness of the pole isn't critical. I'd use a 4x4" fence post and a couple bags of postcrete for convenience.