Pier height advice

[Brutha]

Hi All,

So, rather than go down the home made pier route, in the end I decided to order an Altair pier, which has now arrived, and looks to be a cracking bit of kit!

It will go in the garden (just open air, no observatory etc), and for starters I will be using my Celestron 8SE on it, with the standard alt/az mount. I will need to create a custom adapter plate, but that's in hand and shouldn't be too tricky.

For now, the reason for the pier is mainly to avoid the faff of carrying the scope plus tripod in and out of the house when I want to use it, with a side benefit of a bit less vibration when using the scope. But in the future, I may well get a GEM mount of some form for astrophotography.

The area is currently just grass, so I think I will put some paving slabs down which will surround a central 60cm x 60cm x 60cm concrete block sunk in the ground containing the bolts.

But I'm going back and forth a bit about the height; if I set it according to the usual height it would be at on the tripod, the concrete block would need to be 5cm or so above the level of the surrounding paving. But most pictures I see of the same pier seem to have the base of the pier lower than the surrounding area if anything.

Is this just due to the additional height of GEM mounts? Any advice on where to start is welcome!

Cheers

Brutha

 

[Brutha]

And to add a further question, as I have been doing lots of reading today! 

I am wondering whether paving slabs is a good idea around the scope, due to being slippy in cold weather etc. I am wondering if gravel might be a better bet - any thoughts?

[Swoop1]

I would suggest dry mounting your mount and scope to the pier to see where it puts the EP when the pier is at ground level. This woill give you a good guide to whete you need to raise the height or not. Be careful that everything is stable when testing or have someone to lend a hand. Height of the block wise, there are piers out there that are below the surrounding ground (mine is about 1-2 cm below, others are level and some are set above ground level. Your requirements will dictate the final pier base height.

As for surrounding the pier with slabs or gravel, slabs will be quieter but may get a bit slippery as you say, unless you go for a textured slab for grip. `either way, ensure there is a gap between the pier and the surround to prevent vibration as you move around.

[jacko61]

I have the altair astro pier and have around 12" of concrete above floor level in my shed to get the eyepiece to where I'm comfortable.  That's with a celestron advance GT mount.  I also have the pier top plate at it's fullest height. I started with the concrete at 4 inches above floor level but found it was too low for me and didn't take the scope high enough to clear the walls of my shed.

In the photo, I've raised the floor to the height of the original block after adding 12 inches. The floor isn't touching the block.

 

Graeme

edited to add a pic

Edited June 16, 2021 by jacko61

[Brutha]

On 16/06/2021 at 11:34, jacko61 said:

I have the altair astro pier and have around 12" of concrete above floor level in my shed to get the eyepiece to where I'm comfortable. 

Thanks (sorry for delay, hadn't been back to this site for a while!).

Interesting you have it so high though! Is it used mainly for astrophotography, or do you also do visual astronomy?

[Alan White]

Pier height will have two variables mainly.

The type of use you will put it to, Visual or Imaging

The type of scope as this will dictate the focuser height.

The two will then dictate the pier height as well as any issues of roof above etc.

 

A few nights ago I used a scope on a 6ft or so high pier, it was mounting a large refractor for visual use.

[Brutha]

2 hours ago, Alan White said:

A few nights ago I used a scope on a 6ft or so high pier, it was mounting a large refractor for visual use.

Thanks Alan, in fact this should perhaps have been more obvious for me, having seen the rather impressive “Fraunhofer Refractor” in the Deutsches Museum in Munich (the one that was used to discover Neptune): https://www.atlasobscura.com/places/deutsches-museum-refractor-telescope-neptune

[jacko61]

On 27/06/2021 at 08:58, Brutha said:

Thanks (sorry for delay, hadn't been back to this site for a while!).

Interesting you have it so high though! Is it used mainly for astrophotography, or do you also do visual astronomy?

Both although I'm concentrating mainly on AP.  I'm dead on 6 foot tall and found I was bending over too much to use the scope visually when the pier was set a foot lower then it is now. 

Graeme 

[DAVE AMENDALL]

On 16/06/2021 at 11:34, jacko61 said:

I have the altair astro pier and have around 12" of concrete above floor level in my shed to get the eyepiece to where I'm comfortable.  That's with a celestron advance GT mount.  I also have the pier top plate at it's fullest height. I started with the concrete at 4 inches above floor level but found it was too low for me and didn't take the scope high enough to clear the walls of my shed.

In the photo, I've raised the floor to the height of the original block after adding 12 inches. The floor isn't touching the block.

 

Graeme

edited to add a pic

 Graeme,You have done a nice job raising the Pier. I have always liked the Altair Astro Pier but often thought why they did not make it taller or at least the availability of a tube extension and fitting system with Fracs and SCTs in mind. It would save a lot of work......Dave

[fifeskies]

I too have the same pier.

I am thinking I could do with just another 5cm or so height.

The top plate sits on 4 x 12.5cm 16mm screwed rods. These are pretty damned solid.

Yes I know that longer rods might in theory add to vibrations, but in all honesty at 16mm that's never going to be an issue unless you go very much longer.

So I may just change out the 12.5cm screwed rods, and fit some 20cm rods , upgrading from BZP to stainless steel at the same time.

 

[nameunknown]

I suppose if you have the concrete base for the pier sticking up then its a right faff to hide it if you ever move the mount. Although if you leave it flush or below ground level you can always cover it up, but then the foot of the pier might be exposed to standing water.