AstroGab

Astrophotographers hangout. Invite friends and notice chat bar on bottom.

I need advice on what i should do to make a pier. how deep should i make a 24 x 24 x ??? hole for a 12" tube? I want to make it with concrete.also Can anyone lend some pointers? I will be using a cpc 1100 on a wedge with the orion short tube piggy backed for a guide scope.will i need a plate made? Please help if any of you have done this let me know. Thanks!!

Views: 1631

Reply to This

Replies to This Discussion

Good point Russ, I am going to "do it right the first time" now should i do a 4 foot deep 12" hole or should i do a 4' x 4' x 4 ' square hole with the 12 " concrete pole up from it?

Its probably overkill unless you live far north where there is a deeper frost depth.  if you live in the south 2 feet is probably sufficient.  call your local building department with your city or county.  they can tell you what your frost depth is.  you will want to dig to the frost depth or a couple inchea deeper.

I have an 8" concrete pier build from scratch using this websie as a guide (especially in how to build the bottom and top plate). Here is a pic:
I too dug about 4 feet into the ground and it is proving to be plenty stable carrying a load of about 79 pounds (G11, CW and scope).

Very nice setup.

did you do a tube 4 feet into the ground or is there a base also? Nice set up by the way!!

To be honest, I used a post digger and just took an 8 foot Sono tube 4 feet into the ground. So far so good, like I said it is plenty steady for my set up. If I did it again I would go the extra distance and pour a "foundation" with rebar laid horizontally in the ground.

Thanks Steve!! I guess I will go deep and a little wide.where did you get your plates at?

I had them cut at a scrap metal shop in town. If I remember correctly I paid $20.00 for both of them. 10x10 inch and 1/2 inch thick and used 4 12mm threaded rods 100mm long.

Steve, I'm assuming there 4' of concrete pier above ground level, in a "had to do it again" scenario is that a good working height (a bit higher/lower?) Anybody else have thoughts on the pier height (minus the base/leveling plates+mount head). Thanks, Marc

I would not go any higher than 4 feet above the ground. I'm ~5'5" and can manage everything fine. It was the perfect height with the CG5 but now that I have the G11 it is a pinch tall. Most importantly, no one can see it above my back wall...

I did the exact same setup with mine too. 4 feet deep, 8 foot sonotube.

Putting more weight on mine now and planning even more weight, so I got a new pier from software bisque and will be digging a much more solid setup. Squaring the hole not just a post. Will be digging deeper as well, just to be on the safe side.

I don't know if I can help (my system is smaller EQ-6 mount with - from time to time - a 10" Schmidt-Newton).
The frost line in my case is at about 60 cm so my "hole" is 80 cm deep, 80x80 cm surface at the deepest point and 60x60 cm at surface.
The pier is fixed with 4 50 cm (20 inch) anchors 12 mm (0.5 inch) diameter with extra metal rings on bottom to have a higher rigidity.
1 feet is 30.48 cm.
I'm mounted on this pier since almost 3 years and I haven't notice a movement and the drift tests are all the same.
If you want to make is 24x24 then I suppose that you have to dig at least 2x more than the surface so I would say 48? But that's a lot to fill, do you really have to use the 24x24 dimensions?

RSS

© 2020   Created by Charles Dunlop.   Powered by

Badges  |  Report an Issue  |  Terms of Service