Pier concrete base?

[AndyThilo]

Hi

Im soon getting a pier, the base is 450mm diameter, would a 600mm cube base be ok?

Edited August 12, 2020 by AndyThilo

[Craney]

  600 cubic millimetres ??

err... thats a cube of side...  8mm......  

This is what I built for my pier base.( about 50cm square)

• 

It is a bit deeper than 50cm, but I filled the base with rubble and half bricks, so the concrete making wasn't on the industrial scale...

 

[tooth_dr]

1 hour ago, AndyThilo said:

Hi

Im soon getting a pier, the base is 450mm diameter, would a 600mm3 base be ok?

You bought the pulsar one for sale on here 👍🏼
 

My pier is 500mm at the base and my concrete base is about 80cm square.  I suppose the narrower you go the more chance of movement but depth is important too.  Mostly these things are overdone to prevent failure, which is costly to rectify. 

[Miguel1983]

Got a Pulsar-ish pier and made a 60/60/60cm concrete base for it , that's 400-500kg

 

[AndyThilo]

37 minutes ago, tooth_dr said:

You bought the pulsar one for sale on here 👍🏼
 

My pier is 500mm at the base and my concrete base is about 80cm square.  I suppose the narrower you go the more chance of movement but depth is important too.  Mostly these things are overdone to prevent failure, which is costly to rectify. 

I did :), not sure the missus will approve of it, she asked if it would be camouflaged... But when I told her it meant the mount would be outside permanently and the tripod gone she was happier lol. 

[AndyThilo]

2 hours ago, Craney said:

  600 cubic millimetres ??

err... thats a cube of side...  8mm......  

This is what I built for my pier base.( about 50cm square)

• 

It is a bit deeper than 50cm, but I filled the base with rubble and half bricks, so the concrete making wasn't on the industrial scale...

 

Well ok, 216000000 cubic mm if you want to be precise :D. 

[AndyThilo]

33 minutes ago, Miguel1983 said:

Got a Pulsar-ish pier and made a 60/60/60cm concrete base for it , that's 400-500kg

 

Great, 60x60x60 sound perfect then

[Stuart1971]

19 minutes ago, AndyThilo said:

Great, 60x60x60 sound perfect then

I have a pier with 460mm round base plate, and made my concrete block 650mm cubed, but I used resin anchor bolts that had to be drilled afterwards, they were M16 and the holes were M18, so I had to make sure I was not drilling too close to the edge of the concrete or it could easily crack, I ended up with about 100mm between drilled anchor holes and edge of block, and all went well...So depending on how you are fastening down, it’s something to consider.... 👍😀

Edited August 12, 2020 by Stuart1971

[AndyThilo]

I might go 700mm then, although rotating the block so that the bolt holes line up with the block corners will provide more meat for drilling. I'll use chemical anchors, rawlbolts will for sure crack it eventually.

Edited August 12, 2020 by AndyThilo

[Stuart1971]

7 minutes ago, AndyThilo said:

I might go 700mm then, although rotating the block so that the bolt holes line up with the block corners will provide more mate for drilling. I'll use chemical anchors, rawlbolts will for sure crack it eventually.

Yes, I tried to put the bolts in the corners, but was limited with movement due to only so many ways the pier adapter would fit...

I drilled the holes before it was completely cured as much less chance of cracking, in fact when I got near the bottom of the holes when drilling, the dust coming out was still damp, I left covered for two weeks before drilling, but it was back end of last year and was very wet during the two weeks...

If you wait until it’s fully cured before drilling, , much more chance of cracking, also keep the block damp by wetting every day, after the first couple of days, and leaving covered, as it will crack also if dries too quick....and you will need a good SDS drill for the holes.... 👍😀

Edited August 12, 2020 by Stuart1971

[AndyThilo]

1 minute ago, Stuart1971 said:

and you will need a good SDS drill for the holes.... 👍😀

Got some nice Hilti drills here at the office :), don't think I'd bother with my Ryobi hammer drill lol

[AndyThilo]

Haha been quoted £1200 to make the base. What are these people smoking 😂

[teoria_del_big_bang]

6 minutes ago, AndyThilo said:

Haha been quoted £1200 to make the base. What are these people smoking 😂

What !  That is crazy price. 

I am guessing but after material costs that must be at least £1000 for a days work.

Steve

[Stuart1971]

14 minutes ago, AndyThilo said:

Haha been quoted £1200 to make the base. What are these people smoking 😂

That’s ridiculous, 😮😮 it cost me about £120 plus fours hours of my time.... 😀

[Xsubmariner]

You can’t beat a 1 m square by 4’ deep lump of concrete. It is future proof should you upgrade your mount and pier in the future. Not a Huge cost increase but better than having to start from scratch should you decide to upgrade to a high load Astrophotography setup in the future. 

[DaveS]

My pier sits on a platform just over 2.2 metres square and nominally 0.5 metre thick, plus another 0.3-0.5 metre for foundation. the contractors reckoned just over 8 tonnes of "stuff".

[tomato]

Here is my 1 cubic metre  base awaiting the concrete pouring, constructed for a substantial dual rig pier. There were several comments about it being well OTT, but as @Xsubmariner has posted, I definitely didn’t want to have go back and dig it out to make it bigger.

[AndyThilo]

Most I’ll ever put on mine is a EQ6R Pro and an Edge 8 HD. 600mm cube should be plenty. 

[tomato]

Yes, with that loading I’m sure a 600mm cube will be fine.

[Stuart1971]

1 hour ago, AndyThilo said:

Most I’ll ever put on mine is a EQ6R Pro and an Edge 8 HD. 600mm cube should be plenty. 

It will be perfect, 1m cubed is far to big for any mount and set up that would be used in a garden....totally overkill... 😮

[Xsubmariner]

Haha, I like it. 😂 tempted to change my name to Mr Overkill. Some might say this retaining wall I built last month falls into the same category. A great location for another observatory, but alas my wife would do a “Kill Bill” on me.

 

 

[bottletopburly]

Here’s what I did 600mm square hole approx 800mm deep , all depends started to hit water table , 4x 1200 mm rebar hammered into hole base to give concrete extra hold , run some 75mm gutter pipe(Bigger the better I used 40mm too small )  Into hole for cabling running  to centre even if your not feeding cable just future proof , I built a frame think of it as a top hat with a lid that can be screwed to top of frame and drill pier fixing holes attach threaded bar 600mm long securing with nut either side of ply top board  Remember to bend last 150mm so bar can’t unthread from concrete  place in hole making sure it doesn’t snag anything, no point drilling that’s extra work and not required , hire  electric mixer from hire centre  ,pour concrete then push top hat into concrete and screw down and let set , you can now use the nuts on the underside to level pier if required as the concrete will shrink slightly enough to get a spanner on pics attached to give you an idea how I did it .

[tomato]

2 hours ago, Xsubmariner said:

Haha, I like it. 😂 tempted to change my name to Mr Overkill. Some might say this retaining wall I built last month falls into the same category. A great location for another observatory, but alas my wife would do a “Kill Bill” on me.

 

 

"If some's good, more is better, and too much is just right"😁

 

11 hours ago, Stuart1971 said:

It will be perfect, 1m cubed is far to big for any mount and set up that would be used in a garden....totally overkill... 😮

 I don't have a garden, I have an observatory with a bit of grass next to it.😁