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Equipment Discussions >> Observatories

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TimN
Pooh-Bah


Reged: 04/20/08

Loc: Ontario, Canada
Re: Pier diameter? new [Re: Christopher Erickson]
      #6047546 - 08/26/13 07:14 PM

I probably missed something obvious Terry but why can't you just use J bolts - the kind you get at any hardware store.

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Midnight Dan
Postmaster
*****

Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: Pier diameter? new [Re: TimN]
      #6047569 - 08/26/13 07:28 PM

Quote:

I was simply referring to pier parts.




In that case yes, it's done:



-Dan


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dawziecat
Carpal Tunnel
*****

Reged: 10/20/10

Loc: Rural Nova Scotia
Re: Pier diameter? new [Re: TimN]
      #6047653 - 08/26/13 08:29 PM

Quote:

I probably missed something obvious Terry but why can't you just use J bolts - the kind you get at any hardware store.




Hi Tim:

Twelve inch X 3/4 inch stainless steel J-bolts?
Not likely in any hardware store in Nova Scotia.
Galvanized maybe.

If you know anyone within Canada who will ship that size SS J-bolt to me, please let me know.


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mclewis1
Thread Killer
*****

Reged: 02/25/06

Loc: New Brunswick, Canada
Re: Pier diameter? new [Re: dawziecat]
      #6047762 - 08/26/13 09:33 PM

3/4" SS J bolts are indeed difficult to find locally. I went slightly smaller and didn't even bother to go galvanized. After they're installed and an observatory is raised they'll never be wet again. Mine are covered by a removable part of my decking.

I used 3/4" SS hardware for the rat cage area. It is a much more visible area, plus it's easier to get than the J bolts ... 3/4" threaded rod is quite popular in local hardware stores.

Anti seize is available in most Canadian tire stores - look up Permatex Copper Anti-Seize


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TheSheriff
sage
*****

Reged: 07/15/07

Loc: Yellow n Green, Duck Country
Re: Pier diameter? new [Re: mclewis1]
      #6048057 - 08/27/13 12:46 AM

Quote:

3/4" SS J bolts are indeed difficult to find locally. I went slightly smaller and didn't even bother to go galvanized. After they're installed and an observatory is raised they'll never be wet again.




My thoughts exactly. Use SS for the bling factor or some extreme environmental condition, like on Jupiter. I used 3/4 galvanized threaded rod with a welded anti-rotational tab on the end. It will outlast my grand daughter's children.


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dawziecat
Carpal Tunnel
*****

Reged: 10/20/10

Loc: Rural Nova Scotia
Re: Pier diameter? [Re: TheSheriff]
      #6048288 - 08/27/13 07:37 AM

Anyone have any suggestions as to an anti-rotation tab that I could afix to the end without welding, like with nuts. I plan to use a washer 2" in diameter between two nuts but that isn't much to prevent the rod rotating within the concrete.

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TimN
Pooh-Bah


Reged: 04/20/08

Loc: Ontario, Canada
Re: Pier diameter? new [Re: dawziecat]
      #6048431 - 08/27/13 09:20 AM

Terry, I'm with Mark and Brad and just used local stuff. Galvanized J Bolts for the bottom and SS for rats cage. Should all be easy to get locally. Don't make things too hard - they are already hard enough.

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JJK
Carpal Tunnel


Reged: 04/28/08

Re: Pier diameter? new [Re: TimN]
      #6048490 - 08/27/13 09:56 AM

I used galvanized bolts bent into Ls and haven't had a problem.

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dawziecat
Carpal Tunnel
*****

Reged: 10/20/10

Loc: Rural Nova Scotia
Re: Pier diameter? new [Re: mclewis1]
      #6048497 - 08/27/13 10:00 AM

Quote:

I went slightly smaller and didn't even bother to go galvanized. Mine are covered by a removable part of my decking.

I used 3/4" SS hardware for the rat cage area.





Hi Mark:

Your post confuses me a bit. It seems to describe a metal pier affixed to concrete at or below floor level? But then you have a rat's cage too? Why would you need a rat's cage if the pier can be leveled by shimming the pier base?

I plan a concrete pier with a rat's cage for leveling. So, the only metal fasteners are at the top. Nothing at/below floor level.

I plan to go to Dartmouth tomorrow to TransWorld , apparently THE place for fasteners in this neck of the woods.

I see on their site they have SS "anchor bolts!" I called and asked for SS "L-bolts" and they blew me off.
Looks like they may have SS steel L- bolts after all. They just don't call 'em that.

Edited by dawziecat (08/27/13 10:14 AM)


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mclewis1
Thread Killer
*****

Reged: 02/25/06

Loc: New Brunswick, Canada
Re: Pier diameter? new [Re: dawziecat]
      #6048627 - 08/27/13 11:20 AM

Terry,

While shimming the base between the steel and concrete sections would indeed allow me some flexibility it wasn't enough to make larger changes to the overall height I expected to need, plus the steel pier is really heavy and I had no intention of ever futzing with the base of it. The addition of a nice robust "rat cage" made more sense for me. Plus it also gives me a nice place to store USB hubs, etc. and other bits and pieces.

Another option if you can't get SS L/J/anchor bolts is to simply use a SS threaded rod cut long and then add some plain nuts and a 2" fender washer. That will provide enough surface area to solidly hold them when embedded into the concrete. Just watch how close to the edge the washers end up (depends on the diameter of the concrete pier) ... if it's too close smaller washers can be used. I might also stagger the height of the washers/rods to ensure that there isn't a substantially weaker layer at the point of all three washers.

Since you are going to use the anchor bolts set in concrete to affix your top plate I'd suggest when setting the anchor bolts to use a good solid piece of wood accurately drilled for your bolt pattern (or the actual top plate if you have it) with each anchor bolt installed and with nuts to solidly attach each bolt to it. Don't try to place each bolt separately in the wet cement and then use the wood template to bring them into alignment. Putting all the bolts on the wood template and dry fitting them also ensures that there are not any "close" situations (where you feel you can just nudge the bolt into position). You really don't want one of these bolts to be even slightly off from vertical or horizontally out of position.

Edited by mclewis1 (08/27/13 12:08 PM)


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Midnight Dan
Postmaster
*****

Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: Pier diameter? new [Re: mclewis1]
      #6048649 - 08/27/13 11:39 AM

Hi Terry:

Mark brings up a good point about putting the bolts in the concrete. I used a 2-layer wood form to keep the bolts precisely straight, but I'm sure I went a bit overboard. I think most people just use a single layer of heavy plywood and a couple of nuts on each bolt to clamp it to the wood.

Here's my setup:




-Dan


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dawziecat
Carpal Tunnel
*****

Reged: 10/20/10

Loc: Rural Nova Scotia
Re: Pier diameter? new [Re: mclewis1]
      #6048699 - 08/27/13 12:12 PM

Many thanks, Mark.

I plan on using a 1.5" thick plywood template. Am sweating bullets trying to ensure it is accurate as I will not likely have the actual top plate in hand when the concrete is placed. I won't be trying to "wiggle" the individual rods about in wet concrete. I appreciate they must be accurate and vertical.


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roscoe
curmudgeon
*****

Reged: 02/04/09

Loc: NW Mass, inches from VT
Re: Pier diameter? new [Re: dawziecat]
      #6049392 - 08/27/13 06:12 PM

Quote:

Anyone have any suggestions as to an anti-rotation tab that I could afix to the end without welding, like with nuts. I plan to use a washer 2" in diameter between two nuts but that isn't much to prevent the rod rotating within the concrete.





I'm perhaps confused, but are you talking about threaded rods here? If so, the concrete will stick to them enough that they won't ever turn, if you have a couple of locked together hex-nuts on them, you're doubly protected, if you want, you can bend then just slightly, and you'll be triple-safe.
Jiggle them around a bit as you install them in the concrete or the concrete around them, that action will work the finer particles in the mix into the threads, insuring a truly solid bond.

And, in case nobody's mentioned it in a week or two, vigorously working a rod or stick up and down in the concrete as you fill your tube will break up air bubbles or let them rise to the surface, and will work fines out against the sides of the form. tapping the sides of the form with a piece of wood (like a foot-long hunk of 2x4) also makes for a nicer-looking final product.
R


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JJK
Carpal Tunnel


Reged: 04/28/08

Re: Pier diameter? new [Re: dawziecat]
      #6049620 - 08/27/13 08:32 PM

Quote:

Quote:

I went slightly smaller and didn't even bother to go galvanized. Mine are covered by a removable part of my decking.

I used 3/4" SS hardware for the rat cage area.





Hi Mark:

Your post confuses me a bit. It seems to describe a metal pier affixed to concrete at or below floor level? But then you have a rat's cage too? Why would you need a rat's cage if the pier can be leveled by shimming the pier base?

I plan a concrete pier with a rat's cage for leveling. So, the only metal fasteners are at the top. Nothing at/below floor level.

I plan to go to Dartmouth tomorrow to TransWorld , apparently THE place for fasteners in this neck of the woods.

I see on their site they have SS "anchor bolts!" I called and asked for SS "L-bolts" and they blew me off.
Looks like they may have SS steel L- bolts after all. They just don't call 'em that.




Why bother with a rat cage at all?


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dawziecat
Carpal Tunnel
*****

Reged: 10/20/10

Loc: Rural Nova Scotia
Re: Pier diameter? new [Re: JJK]
      #6050207 - 08/28/13 08:21 AM

Quote:

Why bother with a rat cage at all?




Seems to me there are only two ways to do this, with a third that is "maybe."

1/ Metal pier with provision for leveling at the pier base.
2/ Concrete pier with provision for leveling via a "rat cage."
3/ Maybe, just maybe your concrete surface at the pier top is perfectly level and finished smoothly enough that a top plate can be affixed flush to it and bolted tightly to the concrete surface.

As I see it:

Number one is just too expensive . . .for me anyway. Cost of a 10" ATS pier delivered in Canada would be in excess of 2300 USD plus 15%HST. Only Canadians are likely to understand that the costs will probably be pushing $3,000 CDN by the time this thing actually showed up here. That is $3,000 in addition to the concrete costs for the base!

Number two is very cost effective. The rat cage seems robust enough to me with a trio of 3/4" stainless steel bolts bearing the weight and allowing for precise and easy leveling.

Number three is . . . . maybe. I hope to have the threaded portion of the bolts extend into the concrete so that this option will remain open. Whether I use it or not will depend on how smoothly finished and level I can get the top surface.


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TimN
Pooh-Bah


Reged: 04/20/08

Loc: Ontario, Canada
Re: Pier diameter? new [Re: dawziecat]
      #6050537 - 08/28/13 11:47 AM

I agree your number 2 is cheaper but you can get a metal pier just over 8.5" to fit on a 14" concrete tube for $800 Cdn from Skyshed here in Canada that should be good up to about a 14" scope.

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Footbag
Postmaster
*****

Reged: 04/13/09

Loc: Scranton, PA
Re: Pier diameter? new [Re: dawziecat]
      #6050724 - 08/28/13 01:35 PM

Quote:

Many thanks, Mark.

I plan on using a 1.5" thick plywood template. Am sweating bullets trying to ensure it is accurate as I will not likely have the actual top plate in hand when the concrete is placed. I won't be trying to "wiggle" the individual rods about in wet concrete. I appreciate they must be accurate and vertical.




I waited until I got my top plate before pouring the final pier pour. It was a good thing I did because the template I made for the bolts held them slightly crooked. Fortunately I checked to ensure the top plate fit the bolts after the pour.

With a thick enough template board, it won't be an issue, but make sure you get it right. Personally, I'm glad I waited. You have about 10m to get it right.


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Midnight Dan
Postmaster
*****

Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: Pier diameter? new [Re: Footbag]
      #6050739 - 08/28/13 01:44 PM

Quote:

I waited until I got my top plate before pouring the final pier pour. It was a good thing I did ...




Good advice! I did that too. I used the top plate as a template for drilling the wood piece so I would be sure it was correct.

-Dan


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Raginar
Postmaster
*****

Reged: 10/19/10

Loc: Rapid CIty, SD
Re: Pier diameter? new [Re: Midnight Dan]
      #6050827 - 08/28/13 02:28 PM

Dan, can you detail how you did the top of your brick pier?

Pictures?


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dawziecat
Carpal Tunnel
*****

Reged: 10/20/10

Loc: Rural Nova Scotia
Re: Pier diameter? new [Re: Midnight Dan]
      #6050904 - 08/28/13 03:27 PM

Quote:

I waited until I got my top plate before pouring the final pier pour. It was a good thing I did ...




Can't do it! I just have to procede before Dan's can deliver the plate! To do otherwise likely means no pier at all or extra costs to have the hole excavated next summer. Means no progress at all this season. I'd like to have the pier ready for the 1100 mount which AP tells me will be delivered in November. I'll do what I can to ensure I have the bolts in the correct position and vertical. I'd absolutely hate to enlarge the holes in the top plate but if it comes to that, it will just have to be done!

The shop in Dartmouth will fabricate a set of three 12"X3/4"L bolts in stainless steel, complete with two nuts and two washers apiece for $59 each. Not really much more than I was going to have to pay McMaster-Carr before they cancelled the order.


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