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Backyard wood Pier

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#51 dandabson

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Posted 03 December 2012 - 10:24 AM

If his plates are like mine, you can put several hundred pounds on them and there would be no flex. I was surprised how tough they are.


What is the thickness of steel used for the plates? I will probably doing something similar in the near future.

#52 D_talley

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Posted 03 December 2012 - 01:12 PM

He stated his were 1/4 inch. I think mine were the same.

#53 John Miele

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Posted 03 December 2012 - 06:16 PM

Using a simple finite element model of the top plate, 90 lbs of load will flex the top plate downward by 0.0011 inch and the first natural frequency (up-down "bouncing" mode) is over 300 hz.(i.e., it's stiff). Should be pretty stable. If the entire system were modeled, the deflection would be a little higher and the frequency a little lower, but I don't think it would be enough to cause any issue. I guess if you want you could go with 3/8" thick plates, and I'll certainly change out mine if I find I need to, but it's more cost and harder to drill through...John

#54 Phillip Easton

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Posted 03 December 2012 - 08:27 PM

Here is a shot of the pier with an AT12IN on it. The pier is very stable. I get .12 and .14 RMS results in PHD now.


Very nice! I can see my Orion 190mm Mak-Newt on it. I will have to copy it too.

Cheers!
Phillip

#55 dandabson

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Posted 02 January 2013 - 12:43 PM

I am about to undertake a similar project. I will be mounting a cg5 on top. I am using 4 4x4s bolted and glued together. They are 6 feet long and I plan on setting them 3 feet in the ground with cement. My question is will a 8" auger suffice or will I need a 12" auger. The pier measures 7" square right now. Any idea of how much cement to buy? Thanks in advance.

#56 Raginar

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Posted 02 January 2013 - 02:46 PM

Dan, you can use an 8" auger and just make multiple holes if that makes sense. The 4 4x4s is a good idea; another option is just a single 6x6 for a light mount like that. I used a single 6x6 with my CGEM and it worked really well.

#57 D_talley

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Posted 02 January 2013 - 03:21 PM

I am about to undertake a similar project. I will be mounting a cg5 on top. I am using 4 4x4s bolted and glued together. They are 6 feet long and I plan on setting them 3 feet in the ground with cement. My question is will a 8" auger suffice or will I need a 12" auger. The pier measures 7" square right now. Any idea of how much cement to buy? Thanks in advance.


I would just use an 8 inch auger to dig the hole. The 8 inch is easer to use than the 12 inch. Then follow up with a post hole digger to enlarge it just enough to make sure you have enough room for the concrete.

I only needed two bags of concrete for my pier. I wanted to be able to remove it later.

#58 dandabson

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Posted 02 January 2013 - 03:22 PM

Will not mixing meathod work well on a project of this size?

#59 Raginar

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Posted 02 January 2013 - 04:12 PM

That's what I did on mine. Bought some fence post 'crete. Poured into the hole, balanced it out and leveled it, then dumped the water in.

#60 CharlesW

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Posted 02 January 2013 - 05:12 PM

You might find that using an auger drill bit with a screw tip will make boring through all that wood much easier.

#61 dandabson

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Posted 05 January 2013 - 06:13 AM

Thanks to everyone answering a lot of questions in this thread. My new wood pier is in the ground and the cement is setting up. I used 4 4X4s bolted and glued together. The entire pier is six feet long. Half of it is in the ground. That leaves me about the height of my CG5 tripod extending up from the ground. I was planning on letting it cure for at least 72 hours prior to use however, my clear sky alarm went off for tonight. I will check and see if it is ready for use. My oldest son is seen in this photo after the pier was set and leveled. I sure need to plan all of my projects before he moves to far away from home.

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#62 D_talley

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Posted 05 January 2013 - 08:49 AM

Great job! I hope it is setup by tonight.

#63 ahopp

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Posted 05 January 2013 - 09:08 AM

Great job. I put in a pier as you did with 4 4x4s back in '03. It was for an observatory that I built my God Son. 10 years later and it is solid as a rock.

One note, make sure you put in a level of gravel for drainage. Also, I mounted large joist hangers to the bottom of each side of the peer to act as anchors into the cement.

Tony

#64 dandabson

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Posted 20 January 2013 - 10:31 AM

An update. I was a little nervous. It has been rainy from the second day my new pier was in the ground and the mount attached. I was hoping my cover was keeping everything nice and dry.

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#65 dandabson

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Posted 20 January 2013 - 10:32 AM

Everything looks good to go. What a time saver. Powered it up and the polar alignment was spot on. Love it.

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#66 D_talley

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Posted 21 January 2013 - 11:21 AM

Same here, ground is soaking but the mount is dry and alignment is still on target. I use three covers to cover the mount hardware and I see no evidence of moisture on it.

#67 CharlesW

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Posted 23 January 2013 - 12:46 AM

If you have any of the top plate plywood left over, chuck it up in a vise and install a piece of threaded rod in it just like the mount and torque the nuts down until the wood fibers start to crush. Then torque your pier nuts to the same setting. You'll know you will have the highest clamping force possible on your plates.

#68 Raginar

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Posted 23 January 2013 - 09:13 AM

Charles, that is an excellent idea!

#69 turk123

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Posted 23 January 2013 - 08:01 PM

Just a note for you "northern" folks: For areas that get freezing weather (It's 6 out right now in Ohio) the recommended depth is 35" -38" putting you below the frost line. Your milage may vary but you can look up this number. If you don't go the needed distance down, your pier will get pushed up by the frozen ground. Also, most fence companies use small amounts of concrete in the hole for a reason. The concrete should not be at the surface but in the hole. Setting a treated wooden post in solid concrete will cause the water to be held by the wood (it doesn't drain) and eventually destroy the wood. Ask me how I know! :bawling:

I think I might build this project. I'm tired of hauling my losmandy out for a 2 hour setup!

Turk

#70 turk123

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Posted 23 January 2013 - 08:09 PM

Dwight

Does the Losmandy Pier mount just have one bolt in the center? Is that a solid connection? Can it turn on you?

Turk

#71 D_talley

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Posted 23 January 2013 - 08:20 PM

Just a note for you "northern" folks: For areas that get freezing weather (It's 6 out right now in Ohio) the recommended depth is 35" -38" putting you below the frost line. Your milage may vary but you can look up this number. If you don't go the needed distance down, your pier will get pushed up by the frozen ground. Also, most fence companies use small amounts of concrete in the hole for a reason. The concrete should not be at the surface but in the hole. Setting a treated wooden post in solid concrete will cause the water to be held by the wood (it doesn't drain) and eventually destroy the wood. Ask me how I know! :bawling:

I think I might build this project. I'm tired of hauling my losmandy out for a 2 hour setup!

Turk


I set my pier down three feet with gravel on the bottom to help drain the water. I am glad it does not get cold enough to worry about ground pushing it up. More worried about the rain. I set my concrete about 6 inches below the ground level, which will make it easier to remove the pier later.

#72 D_talley

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Posted 23 January 2013 - 08:27 PM

Dwight

Does the Losmandy Pier mount just have one bolt in the center? Is that a solid connection? Can it turn on you?

Turk


Only one hole in the middle. I worried about it moving and made sure I used lock washers to prevent it getting loose and moving. So far no problems with it moving. One way the mount could move is if you pushed the scope by hand and not use the motors.

#73 aa6ww

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Posted 24 January 2013 - 03:57 PM

Everything looks good to go. What a time saver. Powered it up and the polar alignment was spot on. Love it.


I like that idea allot Dan. I've been wanting to do this for a year at least, now you have me motivated. Id be using a C14 on a G11 so it sure would save on set up time!
One thing I thought of in putting one of these together was to make it just wide enough so I could put a 5 gallon bucket over it to keep the hardware clean and dry, and put a sun dial on top of it so you have something cool to look at in the day time. Something like this:

http://windchimedire...CFSTZQgoda1kA1w

Great Job!!

....Ralph

#74 dandabson

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Posted 25 January 2013 - 05:53 AM

Everything looks good to go. What a time saver. Powered it up and the polar alignment was spot on. Love it.


I like that idea allot Dan. I've been wanting to do this for a year at least, now you have me motivated. Id be using a C14 on a G11 so it sure would save on set up time!
One thing I thought of in putting one of these together was to make it just wide enough so I could put a 5 gallon bucket over it to keep the hardware clean and dry, and put a sun dial on top of it so you have something cool to look at in the day time. Something like this:

http://windchimedire...CFSTZQgoda1kA1w

Great Job!!

....Ralph



I can't imagine why I didn't do it sooner after I settled down. I am retired military and have set up to observe in a lot of different places from all the moving around. When the wife and I settled down and finally bought a house it was on my list of things to do. Finally, I just spent the 2 days of work on it and it has paid off.

#75 Raginar

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Posted 26 January 2013 - 01:18 AM

Dan,

Start looking at a ROR shed and you'll be in business permanently :).

Congrat's on retiring!






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