Steel Pier

[RayD]

On 5/14/2017 at 10:09, 1parsec said:

Using square or round section doesn't make appreciable difference in pier design. As RayD says, its the outside dimensions of the pier that's important.

For example comparing a 6" diameter tube with 1/4" wall section  vs    8" diameter tube with 1/4" wall section.
The 8" tube will be 2.44 times more rigid than the 6"

Often you'll see a nice sized tube mounted on a thin base plate without any braces. This un-does all the good work selecting a suitable tube.
Make sure the base plate is well braced and put the bolt positions close up against the braces. A thick plate with a smaller foot print is much better than a larger thin base.

 

Got mine this morning, and to say it's heavy is somewhat of an understatement.  See the holes close to the webs as noted by Dave (although they look tiny they are 18mm), and the fact that it is a very healthy 220mm diameter, with tapered webs and very thick top and bottom plates.  The top plate is tapped for the Mesu adaptor, which is the plate you can see sitting on top.

If this moves I'm giving up engineering 

[1parsec]

2 hours ago, RayD said:

Got mine this morning, and to say it's heavy is somewhat of an understatement.  See the holes close to the webs as noted by Dave (although they look tiny they are 18mm), and the fact that it is a very healthy 220mm diameter, with tapered webs and very thick top and bottom plates.  The top plate is tapped for the Mesu adaptor, which is the plate you can see sitting on top.

If this moves I'm giving up engineering 

That's a superb job.   If I was making one,  it would look just like that :-)

[smudgeball]

Hi all

Thought I'd drop by with the beginnings of my pier project.

I will be painting it, but just back from the local blacksmith today.

I'm going to drill the holes nearer the support webs but other than that I'm quite pleased.

Neil

[RayD]

2 hours ago, smudgeball said:

Hi all

Thought I'd drop by with the beginnings of my pier project.

I will be painting it, but just back from the local blacksmith today.

I'm going to drill the holes nearer the support webs but other than that I'm quite pleased.

Neil

 

That's looking great Neil 

[Jkulin]

On 18/05/2017 at 16:50, smudgeball said:

Hi all

Thought I'd drop by with the beginnings of my pier project.

I will be painting it, but just back from the local blacksmith today.

I'm going to drill the holes nearer the support webs but other than that I'm quite pleased.

Neil

Neil, Can I ask how you will level and adjust your pier, I imagine that you can rotate to adapter for the pier by slackening the bolts at the side, have you left one side open so that you tighten the mount down?

[StevieDvd]

That pier design allows for the top part to be removed, attached to the mount and replaced. The bolts on the side screw into the removable part. As long as the top is roughly level it can then be polar aligned using the mount adjusters.

 

[smudgeball]

On 24/06/2017 at 23:56, Jkulin said:

Neil, Can I ask how you will level and adjust your pier, I imagine that you can rotate to adapter for the pier by slackening the bolts at the side, have you left one side open so that you tighten the mount down?

Hi

It's getting an NEQ6Pro attached, so not worried as long as it's fairly level.

That'll be down to the concrete pour.

Not going to open a side, just attach top plate to mount.

Again, as long as I sort out North before drilling the holes for the bolts, I'll be ok.

Neil

 

[Adaaam75]

58 minutes ago, smudgeball said:

Hi

It's getting an NEQ6Pro attached, so not worried as long as it's fairly level.

That'll be down to the concrete pour.

Not going to open a side, just attach top plate to mount.

Again, as long as I sort out North before drilling the holes for the bolts, I'll be ok.

Neil

 

 

58 minutes ago, smudgeball said:

Again, as long as I sort out North before drilling the holes for the bolts, I'll be ok.

 

 

 

Neil,

Please explain in simple terms why you need to sort North out before you drill the bolt holes?

I've heard this a lot with steel/concrete piers and my ignorance is getting in the way of logic. I really don't understand why North matters on a pier when you can set the mount on top after and align that properly.

Please help....

[spillage]

@smudgeball Will you not need to polar align the mount and then tighten the mount. If you have to remove the plate and tighten would you not possibly knock it out of alignment.

Would it not be easier to use a circular metal cutter to make a small owl's nest. Even if its only enough to get a ratchet in to tighten it up.

[smudgeball]

As long as the metal lug used for AZ adjustments is aligned North, I'll have enough adjustement with the AZ knobs to polar align.

I've never had an obsy before, so will most likely drill ONE hole, do a polar alignment and position the pier to give me even thread spacing on the AZ adjusters.

Then mark and drill other holes.

No intention of moving it after that.

 

Neil

[Adaaam75]

26 minutes ago, smudgeball said:

As long as the metal lug used for AZ adjustments is aligned North, I'll have enough adjustement with the AZ knobs to polar align.

 

So to confirm, the metal peg in the pier needs to be aligned north for the minor AZ adjustments and that is the only consideration with regard to aligning a pier?

[smudgeball]

13 minutes ago, Adaaam75 said:

So to confirm, the metal peg in the pier needs to be aligned north for the minor AZ adjustments and that is the only consideration with regard to aligning a pier?

That's how I'll be doing it.

I wouldn't say that's the only consideration for polar alignment (that process is well documented)

Sight of Polaris is important if that is what you are using but its not the only way.

Software such as alignmaster is good but obviously we're talking about a GOTO mount. (think I'm right in saying alignmaster doesn't even need sight of polaris ??)

I personally (when using the neq6 on its tripod) use the polar align app on my phone to find polaris position and align my polar scope to that.

I don't get too hung up on polar alignment or I find that half my evening is gone !

Anyway, I'm aware of hijacking this thread, so I'll leave it there.

Neil

[Solar B]

I think everyone has their own preferences and indeed budgets for piers etc , I always had it in my mind that I wanted one with

a levelling table and was lucky enough to source this secondhand one with a unique SS table , installed bang on north and

used exclusively for ? 

 

Brian 

 

[spillage]

If you are not going to be imaging then I would not worry to much about polar alignment. Just get it roughly right as any drift would not be noticed when observing.

If you attache the polar lug to the mount and then make a mark on the mount plate opposite the lug and then in the evening use your eye to sight it up to polaris..(like a rifle sight) and leave it there till the morning or mark its position and then fix it in place.

[ollypenrice]

I wouldn't care whether my pier were square or round but we have four square topped piers in the robotic shed (that is they have square top plates) and these have proved to be a bit snag prone. Our work around has been to run thin metal stips downwards from each of the corners to stop cables getting underneath them.

Olly

[Adaaam75]

Ooooh update! Who'd have thought I'd be lucky enough to have a brother in law who can weld! £200 all in. Cost of steel and powder coating. Just need the time to install it now and I'm set.