Pulsar 2.2 Observatory Building


Almost one year after my first try to build an amateur observatory in my  garden  this was unfortunately discarded due to poor location both in light pollution and water log coming form a nearby golf course grounds. The current location is situated in Istan Mountain around 270m from the sea level and away from light pollution. I am installing the observatory using a Pulsar 2.2M (https://www.pulsarastro.com/).

Description

The Pulsar Observatory Dome provides a high quality, secure and practical housing for your telescope. Providing excellent weather protection for you and your telescope, it allows you to have your instrument ready for use at all times. Whether imaging or visual, having the convenience of a permanent set up adds greatly to your enjoyment of exploring the night sky.

The Pulsar Observatories 2.2 metre full height dome benefits from the following advanced features:
Finest quality, weather proof GRP finish
High quality locking system
Simple design for self assembly
Motorised dome rotation available
Motorised dome shutters available
Accessory storage bays available
Available in white or sage green (other colours - please call)
Dimensions:
Total Height approx 2.47 metres
Dome Diameter approx 2.2 metres
Door Height approx 1.1 metres
Dome Aperture approx 0.6 metres
Ideal for up to 12" telescopes and a variety of installations.






I am housing a 10" Takahashi Telescope with the 16000FLI camera, the pier comes from Germany Its an Euro EMC Observatory Pier P300 - Height approx. 1200 mm, Payload 100 kg Telescope Weight



This  star observatory pier P300 with its pyramid shape is, as the smaller P200, uncompromisingly designed for high load carrying capacity. The upper part of the pyramid has a cross-section which corresponds to a tube with 300 mm diameter, because of this the pier has the name. The lower part, where the effective forces are the highest, the diameter reaches 500 mm at the 1000 mm high version. The stiffness follows the diameter in third power, thus the diameter of 500 mm is already clearly superior to, let´s say a steel tube Ø300 mm and 15 wall thickness, if it is burdened with the particularly critical loading case "bending".

Almost more important than sheer diameter is the conical design, as acting forces are directed into the material mostly as significantly more harmless tensile stress, substantially reducing vibrations. By well-directed tuning of wall thickness, cross section and slope, euro EMC achieves maximum rigidity at very low proper weight - consequently the P300 can be still handled well with muscle power, despite its high payload.

The holes at the ground can be closed for filling the observatory pier additionally with sand.

An adjustable 4-point arrangement forms the especially rigid transition from the welded pyramid to the precision machined surface for receiving the telescope mount. The mounting plate consists of stainless steel and has a regular diameter of 290 mm. We will be glad to take over the adaption of your mount.

A stationary column reaches its theoretical rigidity only with ideal floor anchoring. This fact is rarely given due attention and it is with a screw also not very easy to reach. The pyramid shape with its large surface area and the matching anchor sets provide optimum solutions for this issue.

A hole at the bottom allows accesss to the internal anchoring to the ground.

The pyramid is made of steel sheet and regularly white powder-coated. With this surface, it will withstand common climatological conditions, but can be shimmed with an additional corrosion protection for permanent outdoor operation. For extreme requirements, exclusive use of stainless steel is possible.

The Structure



Based
Pie 




Platform
Based of the Dome

Complete Dome

Completed Dome




Next Step - Internal Equipment Installation








Dome Drive



The mounts will follow the apparent movement of the stars in a smooth arc: ideal for imaging, but through the course of the imaging session, the telescope starts on the west side of the pier pointing east and ends up on the east side of the pier pointing west. 
This non-linear pointing has to be accounted for to ensure that the telescope points through the dome’s aperture at all times, requiring some complex mathematics.
It is the job of the dome control software to do this for you.
However, to do this correctly, the software must know exactly where the telescope is mounted in relation to the centre of the dome, so your first task is to make some careful measurements to obtain the dimensions required.
Using the spreadsheet available below will make it easier to get all the dimensions correct and ready for insertion into your software.
Install the ASCOM software and enter the offsets from your spreadsheet, ensuring the correct signs (positive or negative), into your choice of control software – we used MaxIm DL and POTH (Plain Old Telescope Handset) and my personal choose is Sequence Generator Pro.
Once the above is completed, your telescope and dome aperture will be in sync.
 An example below using my AstroPhysics 1100GTO mount, the dimension is obtained from the mount (see below)





Mount Parameters for Dome Slaving
DimensionmmcmmetresInches
a (RA Centre)120.0012.000.1204.72
d (RA Centre Offset)222.0022.200.2228.74
t (GEM Axis Offset)142.1014.210.1425.59
h (RA Centre Height)192.0019.200.1927.56
Wall Height1330.00133.001.33052.36
Pier Height1200.00120.001.20047.24
Pier Height + h1392.00139.201.39254.80
Pier Offsets
n (North to pier)1005.00100.501.00539.57
s (South to pier)1005.00100.501.00539.57
e (East to pier)1005.00100.501.00539.57
w (West to pier)1005.00100.501.00539.57
Dome Diameter2010.00201.002.01079.13
Dome Radius1005.00100.501.00539.57
Pier Centre (N/S)0.000.000.0000.00
Pier Centre (E/W)0.000.000.0000.00
Dimensions for control software
Total N/S Offset222.0022.200.2228.74
Total E/W Offset0.000.000.0000.00
Total U/D Offset62.006.200.0622.44
Dome Diameter2010.00201.002.01079.13
Dome Radius1005.00100.501.00539.57
GEM Axis Offset142.1014.210.1425.59


Mount Measurements























Dome Measurement

























Assembly of Dome Quadrants