[AZ-Observing] Re: Telescope mounts and the monsoon?
- From: Michael Collins <cal_donley@xxxxxxxxxxxx>
- To: az-observing@xxxxxxxxxxxxx
- Date: Fri, 15 Jun 2018 11:47:07 -0700
On 06/14/18 21:38, Nikul Suthar wrote:
Do you think that having a small air conditioner running inside the
observatory would have the mount + OTA + electronics survive the Phoenix
summer heat? Also the roll-off-roof observatory will occupy almost twice
the amount of real estate than its floor area if we add the area beneath
the roof when it is rolled off. Is it possible to have a flip-top
observatory construction to save the real estate beneath the rolled off
roof in the limited backyard space?
Bill Shaheen touched on your questions, but I'll add some comments, for
what they're worth.
Certainly a small A/C unit will reduce the temperature inside the
building. If you eventually plan to go this route, I would recommend
that you insulate the walls and roof during construction and finish them
on the inside with either drywall or paneling. But, as Bill noted, it
may not be necessary depending upon your equipment. I initially
installed a Celestron C11 on a Losmandy G11 in my observatory and left
both in the building through two full summers. Neither was adversely
affected by the heat. Likewise the A-P 1200 carrying an RCOS 12-1/2" R-C
last summer. At worst, the temperature in the building reached about 50
C, and all of the equipment I use (including two different Point Grey
cameras) are rated for temperatures in that range, particularly when not
operating. Losmandy and A-P use industrial grade or better electronic
components which are qualified to operate to at least 85 C, so there is
a healthy margin. It may be a different story with import mounts which
could well be using consumer grade components, particularly electrolytic
capacitors.
For computers, I have several Dell Latitude business-class machines. I
had docking stations in both my office and the observatory, and simply
carried the machine back and forth. I also installed a router in the
observatory, bridge via the wireless link to my home network, so I had a
GigE network between the cameras and computer in the observatory along
with a slower network link to the Internet (though still fast enough to
stream baseball and hockey games on SiriusXM). A big advantage to the
wireless link between the house and observatory is freedom from concern
about nearby lightning strikes which could cause havoc with a hard-wired
connection. I used an RV power cable and connector (basically, a
glorified extension cord) to power the observatory when in operation
since Chandler does not permit full-time electrical service to utility
buildings.
Before I constructed my building, I sketched several different flip-top
buildings but never found a design that looked particularly satisfying,
or if it was from the utility perspective, safe to operate. Even a small
roof will likely be quite heavy and all of the designs I came up with
had either pinch points or regions of instability in their range of
motion which appeared to be potential hazards to my eye. That said, I've
seen some clever and evidently workable flip-top and slide-off designs
in the Cloudy Nights Observatories forum, so there may be good options.
I'm not one to offer much help there, however.
One design I saw on CN which appeared to be workable and quite elegant
utilized industrial grade roller slides similar to what you would find
on a mechanic's tool box or file cabinet. I believe the slides used
offered 60" of travel with a load rating of 1000 pounds. When closed,
the building had no overhang. Two sets could be used on opposite ends of
a building with a split roof to create an opening nearly 10' long, which
is quite enough for almost any amateur class instrument. Were I to
design a building around these slides, I would pay particular attention
to loads when the roof is open, since they would involve significant
forces in tension which are generally a challenge for wood frame
construction where you really want loads in compression.
Of course, the other option is a dome, which also requires no overhang.
Height requirements increase significantly, however, and you're unlikely
to sell the idea to most HOAs inside city limits.
--
<
mailto: cal_donley@xxxxxxxxxxxx>
--
See message header for info on list archives or unsubscribing, and please
send personal replies to the author, not the list.
Other related posts:
