Piers? Varying questions I need help with.

[Alan White]

Mods if this is in wrong place, sorry.

Does anyone here own one of the great value RVO piers at all?
If you do some feedback please.
Cannot decide if it is too narrow for the height etc.???

Thanks 👍

Edited April 28, 2020 by Alan White

[JeremyS]

2 hours ago, Alan White said:

Does anyone here own one of the great value RVO piers at all?

Not tried one, Alan. I've had a Pulsar pier for years. Initially with a Vixen GPDX and Tak FS102, now with a Gemini Telescope Sysems G41 mount and C11. Highly recommended. 

I'd be wary about the adjustable screws at the top, too. See comments about adjustable platforms on the Pulsar link.

[Alan White]

32 minutes ago, JeremyS said:

I'd be wary about the adjustable screws at the top, too. See comments about adjustable platforms on the Pulsar link.

Who hasn't seen Mr Dalby and the video on Rats Cages!   
Just cannot decide if it's all hype and sales pitch as he was, maybe still is, the maker of said piers.
A lot of piers have the Rats Cage and work well.
Same way folks will say put 5 Million square Miles of concrete under the pier and Peter Drew gets on with a paving slab and concrete blocks.
Always a choice to be made.

Edited April 16, 2020 by Alan White
typos of course

[JeremyS]

2 minutes ago, Alan White said:

Just cannot decide if it's all hype and sales pitch as he was maybe still is the maker of said piers.

I guess it depends on what you load it with, Alan.

I should say that the Pulsar was overkill for the original set-up, but was future proofing. In the ended I needed it 🙂

 

Edited April 16, 2020 by JeremyS

[andrew s]

31 minutes ago, JeremyS said:

I guess it depends on what you load it with, Alan.

I should say that the Pulsar was overkill for the original set-up, but was future proofing. In the ended I needed it 🙂

 

Absolutely,  it also depends on expectations.  To shift an image by an arc second or so does not take very much flexure wherever it is. Most piers will flex with or without rats nests as the loads are  normally off centre.  

I use T Point by Patrick  Wallace that comes with The Sky X, and it is instructive to see the model terms needed to compensate for the various errors. If you are interested Google his site it has lots of fascinating information. He has worked on all the major telescope both optical, microwave and radio. 

The  more "Victorian " the engineering the less flexure but how much you can tolerate depends on the requirements. 

Regards Andrew 

Edited April 16, 2020 by andrew s

[Solar B]

Cannot comment on various piers , but as your only going to install

one once then I'd definitely suggest that pouring some concrete is a must 

and it's not really a big task.

Brian

[Alan White]

On 17/04/2020 at 00:00, Solar B said:

Cannot comment on various piers , but as your only going to install

one once then I'd definitely suggest that pouring some concrete is a must 

and it's not really a big task.

Brian

Pour concrete where Brian?

Fully agree on the need for a solid foundation for any structure, my expectation is for 600 x 600 x 600-900 deep.

But what to put above ground is my quandary based as much on overall cost as the final solid solution.

 

[Solar B]

Into the ground 😀 a friend built this 

cage found for me , I’m not sure how 

much concrete was poured but it 

wasn’t that much.

Brian u

[Alan White]

So looking at other Piers, the Pulsar one.
@FLO shows a picture with a solid top, Pulsar show one with a hole, which is the present version?

FLO picture

 

[JeremyS]

1 hour ago, Alan White said:

So looking at other Piers, the Pulsar one.
@FLO shows a picture with a solid top, Pulsar show one with a hole, which is the present version?

FLO picture

 

Not sure Alan, but you will need an adapter plate to go on top. 

https://www.firstlightoptics.com/pulsar-observatories/pulsar-multi-pier-adapter-plate.html

[1parsec]

10 hours ago, Alan White said:

So looking at other Piers, the Pulsar one.
@FLO shows a picture with a solid top, Pulsar show one with a hole, which is the present version? FLO picture

Hi Alan,    The FLO picture pier with the owls nest would be better than one with the rats nest threaded rod.  
The threaded rods don't offer the same torsional stiffness.  
The tip- tilt resistance of the pier is down to the section of pier tube and how well the gussets between the base plate and vertical tube is done.
I like to see a thick base plate with a footprint slightly larger than the pier tube with the holding down bolt holes drilled close to the gussets.
Some thing like this but say 8 gussets !

[Alan White]

18 minutes ago, 1parsec said:

Hi Alan,    The FLO picture pier with the owls nest would be better than one with the rats nest threaded rod.  
The threaded rods don't offer the same torsional stiffness.  
The tip- tilt resistance of the pier is down to the section of pier tube and how well the gussets between the base plate and vertical tube is done.
I like to see a thick base plate with a footprint slightly larger than the pier tube with the holding down bolt holes drilled close to the gussets.
Some thing like this but say 8 gussets !

 Hi Dave, so thick base, 8 gussets at plate base junction, do you suggest the gussets at low level or all the way up like the long standing Pulsar design?

The bollard pier you had for display, I take it was just to show the mount and not one to use?

 

 

[1parsec]

7 hours ago, Alan White said:

 Hi Dave, so thick base, 8 gussets at plate base junction, do you suggest the gussets at low level or all the way up like the long standing Pulsar design?

The bollard pier you had for display, I take it was just to show the mount and not one to use?

The height of the gussets depends on the section & height of the vertical tube. 

If the diameter and section is substantial enough then the gussets can be kept short just the stiffen the joint between the tube and base plate. 
With piers it's diameter that's King 🙂

The bollard we used at the show would work well in real use.  
 

 

[JeremyS]

37 minutes ago, 1parsec said:

The bollard we used at the show would work well in real use.  

Might have missed something here, Dave. Is this a commercial pier?

[1parsec]

7 minutes ago, JeremyS said:

Might have missed something here, Dave. Is this a commercial pier?

The pier is a re-purposed fork truck bollard used to protect the corner stanchions of a high bay racking.
I used to look at them thinking they'd be perfect as a telescope pier.
The warehouse layout was re-done, the bollards became redundant and I managed to squirrel a few away.  It was many moons ago.  

[Alan White]

And a very nice job the lads made of making one into a pier, it held an AZ100 rather well at the IAS.

Sadly in my quest to keep money building for a new mount, the pier and associated is driven by budget.
So any steel pier is off the table, but a solution has been found.

I am going to cast a 10" concrete one within some vent duct, with a brake disc top. 
Total expected cost abou £130.
See my Observing Area Build thread for progress.

Thanks for all the input from everyone.
It has helped cement 🤣(boom, boom) my decision!

or perhaps not........
Factor in the stainless rods, nuts bolts and more bits and suddenly its over £200 on a concrete pier!

 

Edited April 28, 2020 by Alan White
added a note on cost

[FLO]

On 22/04/2020 at 20:27, Alan White said:

So looking at other Piers, the Pulsar one.
@FLO shows a picture with a solid top, Pulsar show one with a hole, which is the present version?

FLO picture

Our photo shows the current/latest version with welded top-plate. 

HTH, 

Steve 

[Alan White]

HELP please !!!!!!!!

OK, i NEED help, A pep talk or good advice PLEASE.

So far I have dug the hole for the concrete foundation as posted in my Observing Area thread.
It is 700 x 700 x 550 deep at present, see picture....it is also boarded over keeping people and rain out.

As I had said, I was intending to cast a 10" concrete pier using spiral duct, this was from cheapness rather than desire.
But having a duct makes me realise how much I don't like it.
Add in after reading a lot more it needs a load of reinforcing too.
And finding it will cost over £230 for the cast option to complete, the materials all add up!
OK that is still just over 1/3rd of a complete Pulsar one and top........

So I have suddenly got cold feet over the cast option, after all, once cast, it's done and the height is set for good.
The plan is literally set in concrete for the duration.
We will move in years to come as the kids fledge and the Father In Law in his annexe departs us.

So do I cast the base and just stop, have a breather and take stock.
Then perhaps hang a metal jobbie on the foundation at a slightly later date?
So that it can move with us, just leaving a concrete foundation under a concrete paved area.

Or do I press on with a concrete casting and get a pier now?

Oh my goodness, what to do, this is suddenly really stressing me out!!

Any help greatly appreciated please 


 

Edited April 29, 2020 by Alan White

[Alan White]

HELP me please folks..... 

My goodness, what to do, this is suddenly really stressing me out was so true last night and truer today.
I have spent a sleepless night worrying over this......




 

[Saganite]

Hi Alan,

My opinion is, cast your concrete block and put a steel pier there. At least when you do move you can take it with you. The pier that I made would have cost about £300 so not a huge difference in cost.

This is just my opinion of course, but I never entertained having a concrete pier.....

Edited April 29, 2020 by Saganite

[Xsubmariner]

Hi Alan,

I agree with Saganite and would cast the concrete base then fit a steel pier.

For consideration;

I built a concrete pier with rebar support and it worked fine, but the size and construction will depend on what weight you are loading it with. As people have already stated It is surprising what impact a small amount of ringing/flex will cause on a long focal length imaging setup.

When my needs changed and I installed a heavy duty mount/system I had to cut off the concrete pier and fit a steel unit. When you move home you will probably have to cut off any concrete pier, if that is the way you decide to go. With steel you can unbolt and take it with you.

Steel piers do appear in classifieds at a substantial saving so this may be an option,  both of my steel piers were acquired used. Have you tried a wanted ad.

If you decide to go for steel, don’t forget to shutter the top of your hole with suitable packing that you can remove when it sets. This will allow you decouple the pier base from the surrounding concrete base. I would then use a can of expanding foam to fill the gap.

PM me if you wish to discuss in further detail my experience . 

Martin

[JamesF]

May also be worth talking to a local steel fabricator about making a pier up for you.  They're hardly complex in design and it could save a fair bit of the cost of a commercial one.

James

[ShrewView]

Hi Alan

I'm also at the stage of pondering piers for a planned obsy. I too thought of making my own but am currently leaning toward buying something instead. In my case it's partly because of appearance and partly because it may be the easier and quicker option.

If I were planning to move within the next few years as you are I'd be looking to buy a steel one that I could take with me, otherwise I'd only have to rebuild at the new house, which effectively doubles the cost.

You may have already seen and dismissed these but in the short while I've been looking at these I've spotted a few other options to the pulsar you've considered. I've no idea how good they are. but I'm sure others do.

https://www.altairastro.com/altair-skyshed-8-observatory-pier-with-anti-vibration-fins-441-p.asp

https://www.homeobservatoryuk.com/?p=telescope.piers

https://www.telescopehouse.com/explore-scientific-pier-for-eq-5-mounts.html

[Skipper Billy]

I would support the idea of casting the concrete and adding a steel pier for all the reasons given above.

My pier is a short length of scrap thick walled steam pipe with a flange welded on each end - cost me a bottle of single malt. 

Its bolted down flush and although it has a 'rats cage' at the top its 8 x 14mm bolts not 3 weedy 8 - 10mm studs that I can well imagine would allow flexure.

There is about 0.6 cubic metres of concrete in the base. 

It holds a Mesu 200 and about 30kgs of rig without any issues whatsoever.

This from last week on a breezy day.

 

 

[Skipper Billy]

Some photos of the pier are here https://www.davidbanksastro.com/micro-observatory

and the bottom of this page https://www.davidbanksastro.com/micro-observatory