2 Pier Observatory Scenario for Mach2 x2


@mmalik
 

How viable would be a 2 pier scenario in a SkyShed Pod observatory housing TWO Mahch2s. Some assumptions, payload configurations, and observatory dimensions are as follows.

Assumptions
 
  • Red lines in the diagram are the maximum/safe lengths of scopes in neutral position, not necessarily the park position but clear of dome rotation and/or dome closure
  • Green circle is the moment arm for counter weights/shaft clear of the wall insides
  • Intersection of RA/DEC axes at or couple of inches above the wall edges
  • Extreme positions of scope/s can extend beyond wall and dome demarks in a PZT (...a platform where entire top dome section can be pushed out of the way) and/or one operational scope (...at any given time) scenarios
 
Payload (... to be optimally distributed between TWO Mach2s given the tolerances diagramed below)

Desired scenario may be to load 180ED on one and StarFire+85ED on the second?

Epsilon-180ED
Clear aperture: 180mm (7")
Focal length 500mm (19.6")
Focal ratio f/2.8
Length 22.4" (570mm)
Diameter 9.1" (232mm)
Weight 23.5 lbs. (10.7 kg)
 
StarFire 130mm
Clear aperture 130 mm (5.1")
Focal length 819 mm (32.2")
Focal ratio f/6.3
Length 28.5" (724mm) [Retracted]
Diameter 5.5" (140 mm)
Weight: 18 lbs. (8.2 kg)
 
FSQ-85ED
Aperture 85mm (3.3")
Focal length 450mm (17.7") [w/Flattener 1.01x]
Focal ratio f/5.3
Length 21.7" (553mm) [Retracted]
Diameter 3.7" (95mm)
Weight 8.8 lbs. (4 kg)
 
Question: How wide is Mach2 counter weight/shaft rotation circumference (Northern US latitudes)? Are the following tolerances acceptable for the counter weight/shaft to clear the observatory walls while sitting below the wall height? Observatory dimensions listed below. Regards









--
mc2 DSLR | MILC Modifications & Cooling
mc2camera.com


dvjbaja
 

While interesting, the POD internally is very small.  I found it cramped for space with my Mach 1 and FSQ, with minimal access to the sky unless you push the dome completely off.  You must account for the counterweight bar and OTA swing radius very carefully in all potential combinations.  If you are going to spend $20K on mounts and accessories, consider a new roll off roof configuration.  - jg


On Sat, Feb 6, 2021 at 9:21 AM <mike_malik@...> wrote:
How viable would be a 2 pier scenario in a SkyShed Pod observatory housing TWO Mahch2s. Some assumptions, payload configurations, and observatory dimensions are as follows.

Assumptions
 
  • Red lines in the diagram are the maximum/safe lengths of scopes in neutral position, not necessarily the park position but clear of dome rotation and/or dome closure
  • Green circle is the moment arm for counter weights/shaft clear of the wall insides
  • Intersection of RA/DEC axes at or couple of inches above the wall edges
  • Extreme positions of scope/s can extend beyond wall and dome demarks in a PZT (...a platform where entire top dome section can be pushed out of the way) and/or one operational scope (...at any given time) scenarios
 
Payload (... to be optimally distributed between TWO Mach2s given the tolerances diagramed below)

Desired scenario may be to load 180ED on one and StarFire+85ED on the second?

Epsilon-180ED
Clear aperture: 180mm (7")
Focal length 500mm (19.6")
Focal ratio f/2.8
Length 22.4" (570mm)
Diameter 9.1" (232mm)
Weight 23.5 lbs. (10.7 kg)
 
StarFire 130mm
Clear aperture 130 mm (5.1")
Focal length 819 mm (32.2")
Focal ratio f/6.3
Length 28.5" (724mm) [Retracted]
Diameter 5.5" (140 mm)
Weight: 18 lbs. (8.2 kg)
 
FSQ-85ED
Aperture 85mm (3.3")
Focal length 450mm (17.7") [w/Flattener 1.01x]
Focal ratio f/5.3
Length 21.7" (553mm) [Retracted]
Diameter 3.7" (95mm)
Weight 8.8 lbs. (4 kg)
 
Question: How wide is Mach2 counter weight/shaft rotation circumference (Northern US latitudes)? Are the following tolerances acceptable for the counter weight/shaft to clear the observatory walls while sitting below the wall height? Observatory dimensions listed below. Regards









--
mc2 DSLR | MILC Modifications & Cooling
mc2camera.com


Roland Christen
 

8 ft square looks too small for 2 setups. I have a 22ft x 12 ft roll-off roof observatory with 2 piers. Has just the right amount of space to move around in. Room for benches/tables, small cabinet for things like accessories, computer hardware, observing chair, etc.

Rolando

-----Original Message-----
From: mike_malik@...
To: main@ap-gto.groups.io
Sent: Fri, Feb 5, 2021 11:41 pm
Subject: [ap-gto] 2 Pier Observatory Scenario for Mach2 x2

How viable would be a 2 pier scenario in a SkyShed Pod observatory housing TWO Mahch2s. Some assumptions, payload configurations, and observatory dimensions are as follows.

Assumptions
 
  • Red lines in the diagram are the maximum/safe lengths of scopes in neutral position, not necessarily the park position but clear of dome rotation and/or dome closure
  • Green circle is the moment arm for counter weights/shaft clear of the wall insides
  • Intersection of RA/DEC axes at or couple of inches above the wall edges
  • Extreme positions of scope/s can extend beyond wall and dome demarks in a PZT (...a platform where entire top dome section can be pushed out of the way) and/or one operational scope (...at any given time) scenarios
 
Payload (... to be optimally distributed between TWO Mach2s given the tolerances diagramed below)

Desired scenario may be to load 180ED on one and StarFire+85ED on the second?

Epsilon-180ED
Clear aperture: 180mm (7")
Focal length 500mm (19.6")
Focal ratio f/2.8
Length 22.4" (570mm)
Diameter 9.1" (232mm)
Weight 23.5 lbs. (10.7 kg)
 
StarFire 130mm
Clear aperture 130 mm (5.1")
Focal length 819 mm (32.2")
Focal ratio f/6.3
Length 28.5" (724mm) [Retracted]
Diameter 5.5" (140 mm)
Weight: 18 lbs. (8.2 kg)
 
FSQ-85ED
Aperture 85mm (3.3")
Focal length 450mm (17.7") [w/Flattener 1.01x]
Focal ratio f/5.3
Length 21.7" (553mm) [Retracted]
Diameter 3.7" (95mm)
Weight 8.8 lbs. (4 kg)
 
Question: How wide is Mach2 counter weight/shaft rotation circumference (Northern US latitudes)? Are the following tolerances acceptable for the counter weight/shaft to clear the observatory walls while sitting below the wall height? Observatory dimensions listed below. Regards









--
mc2 DSLR | MILC Modifications & Cooling
mc2camera.com

--
Roland Christen
Astro-Physics


@mmalik
 
Edited

Thanks for the feedback; much appreciated. Actually 8 ft. square is just the wooden deck, observatory itself is 7 ft. circle made of prefabricated plastic panels (SkyShed Pod).

As far crammed space goes, I feel that should be manageable in a primarily imaging setup (...I do see the need for space for visual observing though). I don't intend to have desk or other setup in there and most of the computing will be compactly mounted on the pier/s. FYI: I don't intend to guide with Mach2, my stated goal for all imaging in future. Following is the best case scenario I have come up with so far, at least on paper. Regards

Note: There will be bit more space on the wooden deck for other activities while imaging happens in the POD


1/2 the Radius Rule (for PODs)...

What I am proposing is putting piers at about the half-way point of the radius. This probably will be the simplest and safest approach as far selecting the pier center/s goes. Rest (latitude, scope size/type/number, etc.) will have to fall into place within certain limits. Regards

Note: Of course I'll be able vert it all out once I have all pieces in hand especially Mach2



--
mc2 DSLR | MILC Modifications & Cooling
mc2camera.com


weems@...
 

I agree with the others. I found my Pod to be much tighter in practice than I expected. The lack of zenith access was also frustrating. A lot of Pod users end up converting to a roll-off, with a platform kit that Skyshed sells.  I replaced it with an Exploradome, which is theoretically about the same size, but feels much more spacious. And it’s much less affected by wind than the Pod. I don’t think the slotted shutter design would work for your setup, though. So I would also recommend a roll off roof design. If space is tight, you could use a flip up roof instead. 

Chip