Joe asked me for tips for purchasing a pier on which to mount his scope in his yard. My thoughts follow but I'm sure the ATMs here will have even better ideas so I'll ask questions for the ATMs along with my thoughts. +++++ I'm pretty sure piers are available commercially but I've always favored home built models. I guess one extreme would be "Patrick's Pompous Pier Project", pictures of which can be seen in image numbers 108 to 138 at: http://users.wirelessbeehive.com/~paw/PATRICKW03.HTML Obviously "normal" people don't need to go to that extreme. :) For most applications a concrete filled steel pipe cemented into the ground ought to work. I like steel for smaller piers, BTW, because it's easy to weld a flat steel plate to the top and onto which a wedge can be bolted. What diameter and wall thickness for the pipe? I like a thick wall. The steel part of my current pier is 1/2" thick. Diameter? Better too big than too small. Perhaps about the width of the base of the wedge? How deep to bury the pier into the ground? Better too deep than too shallow. FWIW, my first pier (for a C-8 in a ground level observatory) stood one meter above ground but went 1.5 meter into the ground. Fill the pipe? And, if so, with what? Some leave it empty. I used concrete in my first and current piers and sand in my second pier (which was made from 3 oil drums welded end-to-end). Ok, those are my thoughts. Now let's hear from the ATMs. Cheers, patrick
Aloha Patrick All 5 piers that I have constructed are from welded steel tubing (4-8",1-6") with a base plate of 3/8" to 1/2" plate steel w/ a 22" diameter to which 1/4" to 1/2" wall 8" tubing is welded w/ 3 to 6 gussets each. Three leveling holes are made (spaced 120º apart, 1 1/2" in from the edge) thru which are 3/4" threaded rods cemented into the pad. A pair of 3/4" nuts one each above and below the base plate serve to get a level top. The tops are usually machined 1" steel plate so a groove beneath the top cap fits over the pier tube, holes drilled in the top cap anchor the cap to the tube. We've been filling our piers at the Haleakala site w/ sand, used lead tire weights and iron window weights. After final assembly, I'll have the piers sand blasted, primed and painted. My first pier painted 22 years ago is just beginning to show rusting but that's from 4 moves and it is exposed to the mountain elements. I hope this helps, a hui ho Rob http://gallery.utahastronomy.com/main.php?g2_itemId=5914 http://gallery.utahastronomy.com/main.php?g2_itemId=5911
"a hui ho"? I don't think that kind of language is called for on this site. While I would agree he sometimes deserves a good old fashioned "Heave-Ho", I don't thing it rises to the level of a full blown "Hui Ho". Quoting Rob Ratkowski Photography <ratkwski@hawaii.rr.com>:
Aloha Patrick
All 5 piers that I have constructed are from welded steel tubing (4-8",1-6") with a base plate of 3/8" to 1/2" plate steel w/ a 22" diameter to which 1/4" to 1/2" wall 8" tubing is welded w/ 3 to 6 gussets each. Three leveling holes are made (spaced 120º apart, 1 1/2" in from the edge) thru which are 3/4" threaded rods cemented into the pad. A pair of 3/4" nuts one each above and below the base plate serve to get a level top. The tops are usually machined 1" steel plate so a groove beneath the top cap fits over the pier tube, holes drilled in the top cap anchor the cap to the tube. We've been filling our piers at the Haleakala site w/ sand, used lead tire weights and iron window weights. After final assembly, I'll have the piers sand blasted, primed and painted. My first pier painted 22 years ago is just beginning to show rusting but that's from 4 moves and it is exposed to the mountain elements.
I hope this helps, a hui ho Rob
http://gallery.utahastronomy.com/main.php?g2_itemId=5914
http://gallery.utahastronomy.com/main.php?g2_itemId=5911
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My only piece of advice would be to install a weather-proof electrical outlet on the pier, fed by an underground length of Romex. You need not hard-wire it in if it seems too daunting, but can just plug the other end into an existing outlet in the garage. A GFI is a good idea with outdoor outlets (and may be required by code). On Sat, Apr 19, 2008 at 3:45 AM, Patrick Wiggins <paw@wirelessbeehive.com> wrote:
Joe asked me for tips for purchasing a pier on which to mount his scope in his yard.
Joe,
Chuck is right a weather-proof outlet is a must. I buried mine when I was installing sprinklers. My pier is concrete with a cap specific to my mount on the top. It is 10" diameter and is about 5 feet tall and 4 feet into the ground. The Romex was easy to install but I had planned by an outdoor box with wires to connect the Romex to. Erik My only piece of advice would be to install a weather-proof electrical
outlet on the pier, fed by an underground length of Romex. You need not hard-wire it in if it seems too daunting, but can just plug the other end into an existing outlet in the garage. A GFI is a good idea with outdoor outlets (and may be required by code). On Sat, Apr 19, 2008 at 3:45 AM, Patrick Wiggins <paw@wirelessbeehive.com> wrote:
Joe asked me for tips for purchasing a pier on which to mount his scope in his yard.
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participants (5)
-
Chuck Hards -
diveboss＠xmission.com -
erikhansen＠TheBlueZone.net -
Patrick Wiggins -
Rob Ratkowski Photography