jgw12936
sage
Reged: 03/28/07
Posts: 243
Loc: The Woodlands, TX
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The 8 inch pier is plenty big, that is what I have in the picture I attached above. You can also add accessories later since it is a standard size.
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Jim
5" Alvan Clark F/15, 1892
C8 CF XLT
APM/TMB 80/480
TV Pronto 70mm
Tasco 60mm 12TE
Mach1GTO
SBIG 4000XCM
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DeanS
sage
Reged: 07/12/05
Posts: 357
Loc: Nicholasville, Kentucky
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Yep, sometimes just getting things done quickly is worth paying more in the long run. However I think we are all hard headed and like to punish ourselves 
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8" LX200gps
AP1200GTO Mach1GTO
FS-60C Tak E160 C9.25
SXV-H9 ST2000XM STV
Meade 12" Lightbridge
Moonlite Focusers
www.doghouseastronomy.com
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WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 631
Loc: Frankfort, Ky
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Amen, Dean. Well said.
Thanks, Dave. Youve explained things in a way even someone like me can understand.
Sounds like 8" will do the trick. Since I dont know much about this whole subject, I never realized I could just attach a plate over my j bolts to accomodate whatever I get.
That sounds sweet.
So...see anything wrong with the Omega 2 from BYO? Linky.
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Sleep is the Cousin of Death
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Bowmoreman
Carpal Tunnel
Reged: 09/11/06
Posts: 2626
Loc: Bolton, MA
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No problem at all... Looks really nice, btw! I like the idea of the built in AC/DC power supply...
Had Scott had this last year, I would have gotten it...
clear enough skies
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Dave
Ustream
YLive
XT10i, RTP, CGE, TMB80SS, SN8
31T5, 22T4, 13Ethos, 8Ethos, 6&4 Radians; Paracorr
MallincamColorHyperPlus,SBIG STV&237A;CanonRebel Xti
WilderSkiesObservatory(BYO #90)
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WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 631
Loc: Frankfort, Ky
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Hey, Yall.
Weve been at it all day and and I think we got pretty far considering all that we got going on.
We went and got some floating foundation thingies and buried them in the ground and built a floor joist box around our dob slab to help with stability.
We braced everything in with anchors thingies until we ran out of them.
Right now im just waiting on a template from BYO to tell me where to put my J-bolts into the concrete and then Ill be able to do that.
Diane emailed me and said I may have to wait until Scott got back from his latest job and im hoping maybe someone here has one from their own build.
Anybody?
Im going to end up buying the Omega 2 pier from them, anyone know exactly where the j bolts would go, a new Omega 2 owner with a template lying around they could email me?
Its suppose to rain again for the next couple of days so im probaly stuck anyways, I was just hoping to go ahead now and set that concrete for the pier while I had a brief break in the weather.
Heres some pics of where we got to today. Once we can do the concrete for the pier then we can finish the floor joists on the other side and then lay on our floor!
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Sleep is the Cousin of Death
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WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 631
Loc: Frankfort, Ky
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Another shot. We had to peel the top most board of our concrete box and I keep plastic on it 'cos its gonna need some 'fill in' on the sides of it, Ive seena type of concrete filler you can use I just cant place the name.
Theres tiny little holes all where the boards were. i wanna fill them in.
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Sleep is the Cousin of Death
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WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 631
Loc: Frankfort, Ky
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And one trying to show the floating foundation box weve created on one side.
Theres two floating foundation thingies on each side, and it helped us be able to box in around where the floor will go around the slab. we dug them in a braced them with rebar (i got alot left over for some reason!).
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Sleep is the Cousin of Death
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jgw12936
sage
Reged: 03/28/07
Posts: 243
Loc: The Woodlands, TX
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Wow! Looks like you've made some great progress!
I don't have an Omega 2 pier from BYO, so I can't help you with a template. I'll bet it is similar to how I had to do my Le Sueur. They suggested an 18 inch diameter hole 48 inches deep. I used a sonotube with those dimentions. After the hole was complete and sonotube in place, with four pieces of rebar, I loaded it up with concrete and used the form and j-bolts they provided to me, it consisted of two wafer boards with the j-bolt pattern pre-drilled. I simply put in the j-bolts into the form and place them into the concrete with the bottom wafer board flush on the concrete and had it aligned north. You do have to be ready to place the j-botls and wafer board right away, because they can be hard to push into the concrete if you wait too long.
There are a few photo journals of the process that I found helpful, take a look at this one:
Sonotube hole
J-bolts
Edited by jgw12936 (05/18/08 10:48 AM)
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WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 631
Loc: Frankfort, Ky
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Thanks alot, jgw!
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Sleep is the Cousin of Death
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jgw12936
sage
Reged: 03/28/07
Posts: 243
Loc: The Woodlands, TX
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Your Welcome!
It looks like the Omega 2 has four J-bolts, so I would wait for a template and instructions. You may need to know which way to point your template north.
Jim
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Jim
5" Alvan Clark F/15, 1892
C8 CF XLT
APM/TMB 80/480
TV Pronto 70mm
Tasco 60mm 12TE
Mach1GTO
SBIG 4000XCM
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WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 631
Loc: Frankfort, Ky
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That reminds me, can I just use this 4 dollar compass from Walmart and Polaris to get North the best I can, or is there a trick or reason why I must be absolutely sure that im facing dead-on North?
Can you just be sure that im facing North and thats good enough?
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Sleep is the Cousin of Death
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jgw12936
sage
Reged: 03/28/07
Posts: 243
Loc: The Woodlands, TX
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When you have your pier bolted onto the j-bolts and your piertop attached to the top with your GEM mount attached, you will only be able to use your azimuth fine adjustments to polar align your mount. Usually these are +/- a few degrees. Some pier tops have an additional small adjustment, I don't know about the Omega 2. It is important to have your j-bolts set pointing the right direction so you can polar align your mount. I can't tell if your pier is going to have 3 or 4 j-bolts. If yours has three like mine, then you need to have one point of the triagle they form pointing as close to true north as possible. Since your mount looks square, you may have 4 j-bolts where I would think you would need to have 2 j-bolts perpenicular to true north. It just depends on how much wiggle room you have to determine how precise this needs to be. I polar aligned my mount and used string attached to stakes to mark the direction to true north, and had the string stretched across my sonotube. Others have used a compass knowing they had enough wiggle room to account for the difference between true and magnetic north. I have also seen a compass at REI that has a declination adjustment to account for the true vs magnetic north,
REI compass
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Jim
5" Alvan Clark F/15, 1892
C8 CF XLT
APM/TMB 80/480
TV Pronto 70mm
Tasco 60mm 12TE
Mach1GTO
SBIG 4000XCM
Edited by jgw12936 (05/18/08 04:58 PM)
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Joel
Carpal Tunnel
Reged: 07/08/04
Posts: 2055
Loc: Merrimack, NH
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Don't forget to offset north based on your location!
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Joel
10" LX200GPS UHTC-SMT
Vixen 80EDsf
Helix Mount on Oberwerk tripod
Turkey Hill Observatory
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Chris Schroeder
Post Laureate
Reged: 12/11/04
Posts: 4213
Loc: N.E. WI Sky Glow
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Wow, I was gone for a week and look at what I missed. Looking good widowMaker.
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Chris
10" DSH with SC DSC Big Blue
CPC 800 XLT "Onyx"
M102ED S.V. Mellow Yellow
ZS 80FD 10th Anniv The Red Temptress
ZS 66SD "Black Beauty Jr."
PST Golden Boy
POD XL3 http://POD.SchroederCity.com
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WidowMaker
professor emeritus
Reged: 12/29/07
Posts: 631
Loc: Frankfort, Ky
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Thanks, Jgw & Chris.
I just got back from Dean's Doghouse Observatory.
What a setup! Ill never be able to have anything like that, wow.
Hes such a nice guy, and let me take as many pitures as i wanted! Thanks alot, Dean!
Quote:
Don't forget to offset north based on your location!
Can you explain what you mean for me, Joel?
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Sleep is the Cousin of Death
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DeanS
sage
Reged: 07/12/05
Posts: 357
Loc: Nicholasville, Kentucky
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Glad you stopped by, I always enjoy talking scopes with people and feel free to stop by anytime.
Mike, remember that I showed you the compass on the Mach1?
The scope is properly polar aligned yet the compass showed it was not due north. That is our 'offset' for our area. Most mounts will have enough adjustments or allow for that I would imagine.
Dean
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8" LX200gps
AP1200GTO Mach1GTO
FS-60C Tak E160 C9.25
SXV-H9 ST2000XM STV
Meade 12" Lightbridge
Moonlite Focusers
www.doghouseastronomy.com
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astrotrf
super member
Reged: 09/30/07
Posts: 153
Loc: Rodeo, NM
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Quote:
Most mounts will have enough adjustments or allow for that I would imagine.
Magnetic declination can be quite a bit larger than most mounts will be able to adjust for. It's a hair over ten degrees at my observatory, and there's some source of local deflection that seems to add a couple more degrees. 
Magnetic declination
Go out at night and line up your pier with the North Star; never mind the compass. Drive a pair of stakes such that the line between the stakes lines up with Polaris. You can even check a chart before you go out and compensate for the small difference between Polaris and the north celestial pole. You should have no trouble getting within a degree just by eye.
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Terry (astrotrf)
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cocobolo
Carpal Tunnel
Reged: 10/27/07
Posts: 1550
Loc: british columbia, canada
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Only 10 degrees? Try 20 degrees out here! Makes it real fun if you're navigating a boat!
Keith
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Bowmoreman
Carpal Tunnel
Reged: 09/11/06
Posts: 2626
Loc: Bolton, MA
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I agree with Terry's method...
Before Scott got here to build my WSO, I had used my XT10i Dob to point DIRECTLY to Polaris. I then dropped the OTA down to Horizontal, and hung a plumb bob off the top/center of the OTA to the Ground, and marked that location with a stake.
Then noted EXACTLY where the OTA was pointing (in my case my house) and marked THAT location also... If you don't have an obstacle, you could have the OTA point all the way down to the ground maybe, or have someone hold something mebbe?
In my case I used a Green Laser, but you could as easily just sight through your finder (which would likely focus close enough).
The line between the two will be within 1 degree accurate of Due North.
Then Scott just transferred that "north pointing line" to the pier J-bolts template...
I trusted this method more than using magnetic declination offset (mostly because I wasn't sure of the accuracy of my compass!)...
Clear enough skies
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Dave
Ustream
YLive
XT10i, RTP, CGE, TMB80SS, SN8
31T5, 22T4, 13Ethos, 8Ethos, 6&4 Radians; Paracorr
MallincamColorHyperPlus,SBIG STV&237A;CanonRebel Xti
WilderSkiesObservatory(BYO #90)
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Joel
Carpal Tunnel
Reged: 07/08/04
Posts: 2055
Loc: Merrimack, NH
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Yeah what these guys said! Check the chart for your area for magnetic declination. In my case is what 14 degrees so I had to set that in the compass. Just pay attention to the degree and whether it's offset east or west.
I only used a compass and it worked fine for me. You should have a few degrees to play with built into your pier.
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Joel
10" LX200GPS UHTC-SMT
Vixen 80EDsf
Helix Mount on Oberwerk tripod
Turkey Hill Observatory
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