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My Suburban Concrete Pier + cem120 + 12x12 Deck + Nexdome Build thread

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#51 markm75c

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Posted 19 August 2019 - 09:59 AM

Ha - I like the look on the face of your model that shows the space constraints!    I have a son about that age and it is like pulling teeth to get him to help me on these sorts of endeavors - I hope you have better luck than I!

Haha yes indeed, it certainly can be trying at times, though they did help quite a bit with the deck and digging.  They also dont really have an interest in using the telescope unfortunately (my son here is 16, my other is 12 and i have a 3 year old that does love the telescope haha).


Edited by markm75c, 19 August 2019 - 10:00 AM.


#52 Stevegeo

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Posted 19 August 2019 - 10:50 AM

so far everything looks good ..however ..i would suggest a vapor barrier under the floor.

i stapled 10 mil plastic to the underside of floor joists with wood lath across the joists ...

 

but i have from bottom up in this order ...

earth . gravel . vapor barrier.  concrete. 

1 foot air space . vapor barrier. joists. plywood.

then building ..the one foot air space isolates ground temp from building .. i have insulated the underside of building ..which helps a lot in humid or very cold temps.



#53 markm75c

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Posted 19 August 2019 - 02:25 PM

so far everything looks good ..however ..i would suggest a vapor barrier under the floor.

i stapled 10 mil plastic to the underside of floor joists with wood lath across the joists ...

 

but i have from bottom up in this order ...

earth . gravel . vapor barrier.  concrete. 

1 foot air space . vapor barrier. joists. plywood.

then building ..the one foot air space isolates ground temp from building .. i have insulated the underside of building ..which helps a lot in humid or very cold temps.

Interesting, i hadnt considered this, i havent seen many do this either.  Issue is since the decking is down, i really dont want to have to undo it all.  I'm going to have the rubber 3/4 gym mats for flooring and seal the outer edge of the dome with pl max loctite caulking as some have done.  I would hope maybe at least the flooring would help on insulation?



#54 markm75c

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Posted 19 August 2019 - 03:27 PM

on my previous statement about possibly doing the skyshed roll off instead.. i was concerned about wall height (6 foot the typical height) vs my current 52.5" scope height, but given the wall would be 5.5  feet outward (12x12 deck), that means it actually should be more than possible to see 22 degree targets (after i did a brief calculation using H elev = Tan(A elev) * D wall  (means i have an extra 7" to work with in fact, i think if i did this calculation correct)  but i still need to consider the dark adaption advantages of the dome and complete remote ability (so basically i havent abandoned the nexdome at all yet)


Edited by markm75c, 19 August 2019 - 03:33 PM.


#55 Stevegeo

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Posted 19 August 2019 - 07:55 PM

A concern here with the gym mats ...they are prob rubber or vinyl covered  and either way like many materials will collect moisture, underneath between the mat and the wood  and that's not good  (for).. I know this first hand ...that's the very reason why I suggest a vapor barrier under the platform  and if possible insulation .

Insulation could be done easily by lifting the platform . Glue foam board 1in thick under and use lath strips 90degrees to the foam screwed to platform every 2ft .. tapering the foam joints would help tremendously. And help midigate any moisture from the ground .   Moisture from the ground , or air temp difference , what we all hate ..DEW.

A good example of what I am talking about is lift a rubber Matt that has been outside after a rainstorm , but not exposed to the rain .in a porch or garage.....it will be damp ...to stop this moisture, either a barrier with insulation , or if your climate is somewhat dry, insulation alone ..the temp difference slowed by insulating even small, would make a great difference in your maintenance, equipment longevity , and building.  But that's my opinion.



#56 markm75c

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Posted 20 August 2019 - 10:27 AM

A concern here with the gym mats ...they are prob rubber or vinyl covered  and either way like many materials will collect moisture, underneath between the mat and the wood  and that's not good  (for).. I know this first hand ...that's the very reason why I suggest a vapor barrier under the platform  and if possible insulation .

Insulation could be done easily by lifting the platform . Glue foam board 1in thick under and use lath strips 90degrees to the foam screwed to platform every 2ft .. tapering the foam joints would help tremendously. And help midigate any moisture from the ground .   Moisture from the ground , or air temp difference , what we all hate ..DEW.

A good example of what I am talking about is lift a rubber Matt that has been outside after a rainstorm , but not exposed to the rain .in a porch or garage.....it will be damp ...to stop this moisture, either a barrier with insulation , or if your climate is somewhat dry, insulation alone ..the temp difference slowed by insulating even small, would make a great difference in your maintenance, equipment longevity , and building.  But that's my opinion.

I think what people end up doing is combatting moisture issues in other ways, like having a fan blowing at the pier was one i read (during the day i think).

 

However, i'd consider doing some extra steps here, but i think your still suggesting i unscrew all the 5/4 boards though right?  I'm not sure i follow the lath strips and foam board (are the strips wood pieces?), foam board would be pretty expensive wouldnt it?  Are you suggesting foam boards instead of the 10mil plastic or whatever material that was?  Trying to visualize this, as i havent seen anyone show this done in photos at least.  

 

Would just putting 5 or 10 mil plastic overtop the deck boards be bad (trapping moisture i assume, so no good)?   I'd still consider using insulation along the inside perimeter (and outside with caulking) as some have done, in fact some have put what i think is foam material from harbour freight, a gym bench material glued to the entire wall surface of the dome down to the edge of the floor) wiith success in the nexdome forum.



#57 markm75c

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Posted 20 August 2019 - 03:39 PM

My current thinking is to go with a layout like this to avoid the counter weight shaft issue (red square being the 22" lcd location, likely keeping the subpanel and data pathways in the other bay, slightly moving them is all that should be needed).    Putting the lcd in the lower right is the opposite of the original intention which was to be in the other bay in the upper left.  The data wires can just go under the deck in some tubing and come back up in the new spot pretty easily without much modification.

deckwithmount1mod.jpg


Edited by markm75c, 20 August 2019 - 03:40 PM.

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#58 Mel M

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Posted 24 August 2019 - 10:17 PM

Somebody planning a similar set up can save labor by digging the hole only a little larger than the diameter of the above ground pier and pouring the concrete against the undisturbed soil of the sides of the hole. 


Edited by Mel M, 24 August 2019 - 10:20 PM.


#59 markm75c

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Posted 24 August 2019 - 11:04 PM

Tonight I put the Celestron 11 Edge HD on its mount and did some testing.

 

Here my oldest smiling nicely for the camera:

scopeup1.jpg

 

Spent some time learning the basics of the GEM mount (my first).  Struggled a bit with the right angle adapter flipping around and not being able to really fully find polaris despite using an artificial star and centering in both the 9x50 and the scope.  I have a red dot finder somewhere but couldnt find it, i think that would help narrow things down visually.  I did try a 2 star align but something was off there as well.  I was ready to use my asi224 as the polar alignment camera with sharpcap or phd2 drift align (following some tutorials) but of course didnt get that far.  Jupiter looked great with my 1.25" 25mm eyepiece however.

 

Next time ill come armed with the red dot finder and get to the polar alignment, of course by then, ill probably just wait and the dome will be in place as well. (within 2-3 weeks i think)


Edited by markm75c, 24 August 2019 - 11:10 PM.

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