42 replies to this topic

[SimonIRE]

Hi All, 

 

I am battling the urge to buy a heavy duty Baader pier (quite expensive) to hold a 100kg class mount with about 70kg of kit on it. 

 

I like the look of these (see below) and I am curious how one gets one of these made. Would you trust a metal worker to make a pier for your high precision kit? The pier, after all, is an extension of the mount and deserves attention. 

 

Could you show me your solutions and perhaps tell me what you think?

 

Many thanks,

 

Simon

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Edited by SimonIRE, 21 September 2020 - 05:43 AM.

[ssagerian]

Hi SimonIRE,

is this made by a specific company or are you talking about taking some plans to metal fabricator? Are there plans freely available that you can point us to, a link perhaps? Do you have a set of plans? electronic or other?

 

Im not sure what you mean by can you trust metal workers, have you ever programmed a CNC plasma or water jet cutter? They are highly skilled technical craftsmen and often have to deal with people with half baked incomplete, or impossible to implement ideas.

Steve S

Edited by ssagerian, 21 September 2020 - 06:24 AM.

[SimonIRE]

Im not sure what you mean by can you trust metal workers, have you ever programmed a CNC plasma or water jet cutter? They are highly skilled technical craftsmen and often have to deal with people with half baked incomplete, or impossible to implement ideas.

Steve S

Many thanks Steve, 

 

I definitely fall into this category (no offence was implied). 

 

The design of the pier as well as the materials I imagine are important. I don't have any plans - yet. However I was keen to see the designs others have implemented for heavy loads. 

 

Simon

[iwannabswiss]

Had my pier fabricated by a friend of mine. I gave him the information about what I was looking for and plans from Software Bisque; he was able to take it from there. I don't think there is anything wrong with going this route, especially if you can save yourself a few dollars.

 

[macdonjh]

Piers can be quite simple, actually.  A good source of information that might give you confidence not to over-think the design is in a thread called "pier engineering", it was started by Cloudy Nights member speedster.  

 

My simple design, using concrete, can be seen in this thread:  https://www.cloudyni...hl= poorly lit

Granted, I don't do photography, but it's been stable for the past six years now.

Edited by macdonjh, 21 September 2020 - 02:18 PM.

[t-ara-fan]

Piers are pretty simple. They don't have to be true to 0.0001°.  It does help if the machining of the holes on top will fit your mount or adapter plate, and if the holes at the bottom fit over the bolts sticking out of your base.

A solid base i.e. a 1,000-2,000lb of concrete poured into an open hole is a good start, if you are still at that point.

 

This is a 54" tall 8" Sched. 20 steel pier. A friend made it for me.  A Mach1GTO and TAK TOA-130 sits on it. Not quite as heavy as your equipment, so you would need 10" or 12" diameter. I had four 1/4-20 holes tapped into the south side, for trays and my GTOCP4.  I 3D-printed the trays, which have holes for hex drivers, and holes for the cables going up the pier.  The middle tray has a rectangular recess to hold my dew controller, USB hub, and Powerpole 12V distribution block.

 

 

 

[speedster]

Howdy Simon!

 

We like to think that heavy things needs massive support but that's not what we are after.  A 1/2" pipe will support over 7,000 pounds.  But, consider a 1/2" pipe 40" high - it's easy to deflect it.  What we are after is limiting deflection to something less than a camera is capable of recording.  The pier engineering threads mac references above explain it with examples and some calcs for common sizes and lengths.

 

Yes, you can absolutely trust a metal worker.  Baader does not have a lab manufacturing piers.  They show a design to a local fabrication shop and those guys fab it for them.  If the volume gets high, it's farmer out to China.  Rounds and squares can be bought online and simply welded to the end of a pipe.  The only machining is then drilling the holes.  Sure, the Baader tapered octagon looks cool but you can have an even stiffer pier and save nearly $2,000 dollars. 

 

https://www.cloudyni...ier engineering

[rimcrazy]

Here are a few shots of my pier.  My son had his own metal fabrication shop when this was made.  Helps a lot to know someone with access to CNC Plasma cutters and water jet technology!  The pier stands about 10' high and weighs about 1000lbs.  This is more to show what can be done if you have access to a metal shop or someone with a shop.  To contract to have this pier made would be quite expensive.  My son made this and the steel was purchased at his discounted rate and most of the metal fabrication sans some water jet work was all done in his shop.

 

For your pier you would not need to go nearly as high.  I needed to lift everything up about 8' to get it to the level of the dome.  Had I made a shorter building it might not have needed to be so tall.  I was wanting to show you the concept of the pier.  A larger diameter pipe with stiffer gussets on the side would most likely be all you would need I would think.

 

Album: Overgaard Outreach Observatory

7 images

0 comments

Edited by rimcrazy, 22 September 2020 - 07:27 AM.

[macdonjh]

Not quite as heavy as your equipment, so you would need 10" or 12" diameter. 

It would look funny by today's practices, but a 4" or 6" pipe would be plenty to hold SimonIRE's equipment.  

 

SimonIRE, If you have some estimates of how much the mount you want will weigh (you've stated you anticipate 70 kg of gear),  the math isn't hard.  I'd be happy to post some of the basic calculations.  I also agree with speedster:  if you have a fabrication shop in your area talk with the owners or managers.  They might be willing to let some of their guys "moonlight" on your project.  Many of those guys have their own tools as well, so they could make you something over the weekend.  Please resist the urge to specify to a fabricator what he's making for you has to be accurate to +0.03mm, you'll have bragging rights but less money in your pocket.  Normal fabrication tolerance for something like a pier is +3mm and you'll have plenty of adjustment in your anchor bolts and when polar aligning your mount to make things perfect.

[t-ara-fan]

It would look funny by today's practices, but a 4" or 6" pipe would be plenty to hold SimonIRE's equipment.  

 

Probably.  All the "deflection talk" doesn't mean much to me, who pushes on their pier with 5lbs force while taking photos?

 

I wouldn't make the pier a smaller diameter than the base of the mount. Otherwise your astrobuddies will nickname it The Mushroom (or something worse!).

[Digital Don]

I took the drawing below to a local steel fabricator.  Top and bottom plates are 3/4" steel plates, 12" square.  The tube is about 8" diameter.  He had the materials on hand which reduced the price which came to $200 13 years ago.  I figure about a buck a pound!

 

The pier was originally designed for a Celestron 11 on a Celestron 14 wedge.  However, I also had holes drilled in the upper plate to accommodate future scopes.  The picture below shows the current configuration - an alt-az  CPC 1100 on second upper plate.  Four  3/4" threaded rods connect the upper pier plate to the plate (3/4" steel, 12" square) holding the telescope.

 

Don

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[t-ara-fan]

   The pier stands about 10' high and weighs about 1000lbs.  

 

My 8" pier is 56" tall and stands on a 2" bit of the concrete base that protrudes above the slab.  When I am up on a step-stool putting my scope on the mount, it seems way to high because the dovetail clamp is 6' above the ground.  When I am shooting Jupiter at 12° elevation over my 7' observatory walls I like the extra height.

[SimonIRE]

Here are a few shots of my pier.  My son had his own metal fabrication shop when this was made.  Helps a lot to know someone with access to CNC Plasma cutters and water jet technology!  The pier stands about 10' high and weighs about 1000lbs.  This is more to show what can be done if you have access to a metal shop or someone with a shop.  To contract to have this pier made would be quite expensive.  My son made this and the steel was purchased at his discounted rate and most of the metal fabrication sans some water jet work was all done in his shop.

 

For your pier you would not need to go nearly as high.  I needed to lift everything up about 8' to get it to the level of the dome.  Had I made a shorter building it might not have needed to be so tall.  I was wanting to show you the concept of the pier.  A larger diameter pipe with stiffer gussets on the side would most likely be all you would need I would think.

 

 

Blimey - that's a serious looking pier. 

[macdonjh]

Probably.  All the "deflection talk" doesn't mean much to me, who pushes on their pier with 5lbs force while taking photos?

 

I wouldn't make the pier a smaller diameter than the base of the mount. Otherwise your astrobuddies will nickname it The Mushroom (or something worse!).

Probably nobody, which is part of the point, really.  Us astronomers have a couple of things in our favor when it comes to piers.  First, in the world of structures, our loads are really tiny.  Really, a heavy mount, scope and imaging train adding up to 200 kg is a laughably small load when you compare it to the compressive strength of the materials we use for our piers.  Second, our loads are typically well balanced statically and even pretty well balanced dynamically.  That means the loads on our mounts and piers stay largely compressive, there is hardly any bending applied.  You said it yourself when you wrote, "...pushes on their pier with 5lbs...".  Five pounds is pretty small when you consider SimonIRE thinks he's going to have 100 kg or more on his pier.  But you know he'll have it balanced well so the "side loads" will be negligible.

 

Don't get me wrong, I didn't follow my own advice when I built my pier:

 

Concrete is cheap, I had to rent an auger anyway, and I didn't want there to be any chance I'd want to tear it out and rebuild it.  I went big.  That photo is old, my pier doesn't look quite that oversize now that the G11 has been replaced by a MI-250.  Besides, I agree with you, an Astro Physics 1600 would look funny on a 4.5" diameter (114mm) pier, even if it would be structurally suitable.  What I am urging is for fellow astronomers to not make pier building more complicated (and costly) than it is.  

Edited by macdonjh, 23 September 2020 - 07:38 AM.

[SimonIRE]

What I am urging is for fellow astronomers to not make pier building more complicated (and costly) than it is.  

This is my problem. I could default and get a Baader pier that is custom made for the mount in question, but it is over 2k. 

 

It seems ridiculous. Although I am handy with wood, I have no experience with metal. I am tempted to get a pier made, but I am assuming, to have it CNC machined and then powder coated, I will still end up spending about £500. That's fine if the final product is right - but I don't want to waste that money on something that doesn't quite work. 

 

If you have a 14k mount sitting on the thing, you don't want to neuter it with a poor pier design. 

 

Feel free to comment, but understand, this is not an area where I have expertise, so to some of you, this may look like I am overthinking it...

[iwannabswiss]

This is my problem. I could default and get a Baader pier that is custom made for the mount in question, but it is over 2k. 

 

It seems ridiculous. Although I am handy with wood, I have no experience with metal. I am tempted to get a pier made, but I am assuming, to have it CNC machined and then powder coated, I will still end up spending about £500. That's fine if the final product is right - but I don't want to waste that money on something that doesn't quite work. 

 

If you have a 14k mount sitting on the thing, you don't want to neuter it with a poor pier design. 

 

Feel free to comment, but understand, this is not an area where I have expertise, so to some of you, this may look like I am overthinking it...

You're overthinking it. Get one made locally; just make sure you have the right dimensions, and you'll be fine.

[t-ara-fan]

   You said it yourself when you wrote, "...pushes on their pier with 5lbs...".  Five pounds is pretty small when you consider SimonIRE thinks he's going to have 100 kg or more on his pier.  But you know he'll have it balanced well so the "side loads" will be negligible.

 

I was actually referring to a transient that would upset guiding. If balance shifts by a few pounds over 4 hours of tracking, that would be a small deflection that is easy to guide out. Or just ignore.
 

[macdonjh]

This is my problem. I could default and get a Baader pier that is custom made for the mount in question, but it is over 2k. 

 

It seems ridiculous. Although I am handy with wood, I have no experience with metal. I am tempted to get a pier made, but I am assuming, to have it CNC machined and then powder coated, I will still end up spending about £500. That's fine if the final product is right - but I don't want to waste that money on something that doesn't quite work. 

 

If you have a 14k mount sitting on the thing, you don't want to neuter it with a poor pier design. 

 

Feel free to comment, but understand, this is not an area where I have expertise, so to some of you, this may look like I am overthinking it...

I agree with iwannabswiss, get the correct dimensions, put them on a drawing and give them to a local fabricator and you'll get a pier which works fine.  Heck, you can do most of the metal work yourself with wood working tools.  Both aluminum and plain steel can be cut with normal blades and bits.  Steel will wear out regular bits pretty quickly, though, so don't use your good tools (or buy some disposable tools).

 

Your pier will have three components:

 

Base plate: to bolt to your concrete footer/ foundation.  It can be round or square, it doesn't matter.  You'll need to provide the following dimensions to a fabricator:

• Thickness of the plate, 6mm will look a little light, 12mm will look good, 19mm is overkill
• Overall dimensions of the plate, e.g. 300mm diameter or 300mm x 300mm
• Size and location of the bolt holes, e.g. 4 ea 14mm diameter holes (for 12mm bolts) at 90^o on a 250mm bolt circle (that will tell the fabricator you want four 14mm holes spaced 90^o apart, the centers of the 14mm holes will be on a circle 250mm in diameter)

 

Column: you only need a couple of dimensions for this: diameter, thickness and length.  To match the base plate dimensions I assumed above, I would try using standard pipe, DN8, schedule 40, and however long you need to get your scope at the right height for you.  That gets you standard 8" sch 40 pipe (219mm OD x 8.2mm thick, heavy but readily available).  You can also use square or rectangular tubing, e.g. 200mm x 200mm x 6mm square tube.  I'm sure that will be less available and more expensive than pipe, though.

 

Top plate: provide the same basic dimensions as for the base plate above:

• Thickness of the plate, I suggest 12mm
• Overall dimensions, this will be based on the base of the mount you're going to install
• Size and location of the bolt holes, again, your mount company should provide you with a drawing which shows the bolt pattern you need

 

Then the column gets welded to the base plate and the top plate welded to the column.  Tell the fabricator squareness is important, the top and bottom plates should be parallel to within 0.5mm across their width (or whatever tolerance you want).  Then you can have your pier painted or powder coated.  When it comes time to install it you'll spin nuts onto your anchor bolts (the bolts embedded in your concrete), set your pier over the bolts and onto the nuts, then spin another set of nuts onto the anchor bolts.  You'll adjust the lower set of nuts to make your top plate level then tighten the top set of nuts to secure your pier.  If you want, you can then pack the space between your footer/ foundation and your base plate with mortar or concrete but you don't have to.  Finished.

 

If you provide me with some dimensions (and are patient) I can get you a drawing...

Edited by macdonjh, 23 September 2020 - 12:32 PM.

[macdonjh]

I was actually referring to a transient that would upset guiding. If balance shifts by a few pounds over 4 hours of tracking, that would be a small deflection that is easy to guide out. Or just ignore.
 

Gotcha.  But, still, we both agree, "who would do that?"  And, as you said, if your gear isn't quite perfectly balanced and the load shifts as the mount tracks, the deflection will be tiny and occur slowly so it will be easily guided out.

[macdonjh]

I agree with iwannabswiss, get the correct dimensions, put them on a drawing and give them to a local fabricator and you'll get a pier which works fine.  Heck, you can do most of the metal work yourself with wood working tools.  Both aluminum and plain steel can be cut with normal blades and bits.  Steel will wear out regular bits pretty quickly, though, so don't use your good tools (or buy some disposable tools).

 

Your pier will have three components:

 

Base plate: to bolt to your concrete footer/ foundation.  It can be round or square, it doesn't matter.  You'll need to provide the following dimensions to a fabricator:

• Thickness of the plate, 6mm will look a little light, 12mm will look good, 19mm is overkill
• Overall dimensions of the plate, e.g. 300mm diameter or 300mm x 300mm
• Size and location of the bolt holes, e.g. 4 ea 14mm diameter holes (for 12mm bolts) at 90^o on a 250mm bolt circle (that will tell the fabricator you want four 14mm holes spaced 90^o apart, the centers of the 14mm holes will be on a circle 250mm in diameter)

 

Column: you only need a couple of dimensions for this: diameter, thickness and length.  To match the base plate dimensions I assumed above, I would try using standard pipe, DN8, schedule 40, and however long you need to get your scope at the right height for you.  That gets you standard 8" sch 40 pipe (219mm OD x 8.2mm thick, heavy but readily available).  You can also use square or rectangular tubing, e.g. 200mm x 200mm x 6mm square tube.  I'm sure that will be less available and more expensive than pipe, though.

 

Top plate: provide the same basic dimensions as for the base plate above:

• Thickness of the plate, I suggest 12mm
• Overall dimensions, this will be based on the base of the mount you're going to install
• Size and location of the bolt holes, again, your mount company should provide you with a drawing which shows the bolt pattern you need

 

Then the column gets welded to the base plate and the top plate welded to the column.  Tell the fabricator squareness is important, the top and bottom plates should be parallel to within 0.5mm across their width (or whatever tolerance you want).  Then you can have your pier painted or powder coated.  When it comes time to install it you'll spin nuts onto your anchor bolts (the bolts embedded in your concrete), set your pier over the bolts and onto the nuts, then spin another set of nuts onto the anchor bolts.  You'll adjust the lower set of nuts to make your top plate level then tighten the top set of nuts to secure your pier.  If you want, you can then pack the space between your footer/ foundation and your base plate with mortar or concrete but you don't have to.  Finished.

 

If you provide me with some dimensions (and are patient) I can get you a drawing...

I guess I should say, I didn't want to mess with any of that, so I just poured my entire pier in concrete.  The local building supply store had a few different cardboard forming tubes available (I wanted 10", but chose 12" when 10" wasn't available).  I used a rented auger to drill a hole where my observatory would be, set some rebar (also purchased at the local building supply store) in the hole and then mixed and poured 440kg of concrete. 

 

When the hole was full to ground level I set my forming tube (cut to the correct length with a hand saw) over the rebar and pushed it a few inches into the ground (just to make sure I had smooth round concrete visible when I was done) and then continued mixing and pouring concrete.  

 

When the forming tube was full, I set a Losmandy MA adapter with all the anchor bolts installed into the wet concrete and packed the concrete around the anchor bolts.  I scraped away the excess concrete.  Then I used a carpenter's level to push the forming tube such that it was plumb and then used the level to tip and tilt the Losmandy adapter until it was level.  Yes, you're right, I should have used to wood to brace the forming tube but I simply checked it for plumb several times throughout the day and adjusted it as necessary.  It was fine.  I still laugh about that, though, I know better.  

 

There's a bit more to it (packing or vibrating the concrete, and I have conduit inside the concrete), but if you're really interested in that, I'll provide more details then rather than diverting this thread more.

[SimonIRE]

Thanks all.
I’ve made contact with a few local fabricators and I’ll see what they say. 2k for a pier seems ridiculous

[SimonIRE]

I agree with iwannabswiss, get the correct dimensions, put them on a drawing and give them to a local fabricator and you'll get a pier which works fine.  Heck, you can do most of the metal work yourself with wood working tools.  Both aluminum and plain steel can be cut with normal blades and bits.  Steel will wear out regular bits pretty quickly, though, so don't use your good tools (or buy some disposable tools).

 

Your pier will have three components:

 

Base plate: to bolt to your concrete footer/ foundation.  It can be round or square, it doesn't matter.  You'll need to provide the following dimensions to a fabricator:

• Thickness of the plate, 6mm will look a little light, 12mm will look good, 19mm is overkill
• Overall dimensions of the plate, e.g. 300mm diameter or 300mm x 300mm
• Size and location of the bolt holes, e.g. 4 ea 14mm diameter holes (for 12mm bolts) at 90^o on a 250mm bolt circle (that will tell the fabricator you want four 14mm holes spaced 90^o apart, the centers of the 14mm holes will be on a circle 250mm in diameter)

 

Column: you only need a couple of dimensions for this: diameter, thickness and length.  To match the base plate dimensions I assumed above, I would try using standard pipe, DN8, schedule 40, and however long you need to get your scope at the right height for you.  That gets you standard 8" sch 40 pipe (219mm OD x 8.2mm thick, heavy but readily available).  You can also use square or rectangular tubing, e.g. 200mm x 200mm x 6mm square tube.  I'm sure that will be less available and more expensive than pipe, though.

 

Top plate: provide the same basic dimensions as for the base plate above:

• Thickness of the plate, I suggest 12mm
• Overall dimensions, this will be based on the base of the mount you're going to install
• Size and location of the bolt holes, again, your mount company should provide you with a drawing which shows the bolt pattern you need

 

Then the column gets welded to the base plate and the top plate welded to the column.  Tell the fabricator squareness is important, the top and bottom plates should be parallel to within 0.5mm across their width (or whatever tolerance you want).  Then you can have your pier painted or powder coated.  When it comes time to install it you'll spin nuts onto your anchor bolts (the bolts embedded in your concrete), set your pier over the bolts and onto the nuts, then spin another set of nuts onto the anchor bolts.  You'll adjust the lower set of nuts to make your top plate level then tighten the top set of nuts to secure your pier.  If you want, you can then pack the space between your footer/ foundation and your base plate with mortar or concrete but you don't have to.  Finished.

 

If you provide me with some dimensions (and are patient) I can get you a drawing...

 

Thanks for all these details - appreciate the effort. 

 

I've made contact with a good local fabricator. I need to discuss with him what I need in terms of dimensions. I would like the pier diameter to be at least as large as the mount base - actually I would like it a bit bigger. The base I am unsure of - it will only be 100cm high so I am guessing the base plate doesn't need to be much larger than the pier diameter. 

[SimonIRE]

Hi All, 

 

Some points, following talking to my man...

 

• Price aside, what do you think is the best material for a pier. Is stainless steel overkill? The fabricator gave me a list of the options. For something that will see the outdoors a fair bit with reasonable temperature fluctuations I thought stainless steel or galvanised steel?

 

• Is there any benefit to making it very weighty - i.e. going with a thick diameter pipe? Part of me imagines something very heavy as being good, but is there an issue with "storing energy"? 

 

• I get the impression gussets are relatively pointless - I never liked them. Let me know what you think.

 

Simon

[SimonIRE]

Incidentally, do you think this design (albeit with at 100cm) would be sufficient i.e. the diameter of the tube?

 

The user in the photo has a GM4000 which is rated for 150kg so the answer to my question seems obvious, but his pier is very short. I would be proposing something close to double the height of tube part of this pier. 

 

 

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[t-ara-fan]

 I would try using standard pipe, DN8, schedule 40, ..

The stiffness is all from the diameter.  Doubling the weight by going to schedule 40 from schedule 20 might add 1% to the stiffness.

 

Thanks all.
I’ve made contact with a few local fabricators and I’ll see what they say. 2k for a pier seems ridiculous

£2000?  That seems very high.

 

 

 

  I would like the pier diameter to be at least as large as the mount base - actually I would like it a bit bigger. 

If the pier has a really large diameter it is easier to crash into.

 

Incidentally, do you think this design (albeit with at 100cm) would be sufficient i.e. the diameter of the tube?

The double rat-cage looks terrible in terms of stiffness compared to the main steel tube.  IMHO you only need a rat cage if you have to reach a bolt under the mount to attach it to the pier, like with a HEQ5.  You don't need the pier top perfectly level for Polar Alignment.
 

Edited by t-ara-fan, 24 September 2020 - 10:58 AM.