Download What to do to a Dob

What to do to a Dob
Presentation by Keith Rickard
27 September 2012
Cleaning the mirror
Don’t!
Cleaning the mirror
Yuk!
Cleaning the mirror
What do you need?
1. Tap water
2. Washing-up liquid
3. 5 Litres of distilled water
4. Cotton wool – preferably surgical
5. Vessel large enough to take the mirror
6. About an hour of your time
Removing the mirror
Lay the telescope on a flat surface.
Removing the mirror
Locate the tube fixing screws – note an alignment mark for replacing the cell
Alignment mark
Removing the mirror
Gently withdraw the mirror cell
Removing the mirror
Removing the mirror
Locate the mirror fixing brackets
Removing the mirror
Unscrew and remove the brackets
Removing the mirror
Carefully remove the mirror from its cell
Washing the mirror
Fill the trough with tap water
Washing the mirror
Put in a sparing amount of washing-up liquid
Washing the mirror
Swish the water around to get an even spread of soap
Washing the mirror
Gently place the mirror in the water and leave to soak for about 15 mins
Washing the mirror
The mirror should be about 2cm below the surface
Washing the mirror
Gently swish the water across the water for about 5 mins
Washing the mirror
Use only the weight of a swab of cotton wool to remove stubborn marks
Washing the mirror
Remove the mirror while getting ready to rinse it
Rinsing the mirror
Rinsing the mirror
Use distilled / de-ionised water. This 5L container cost £3.99.
Using this water will mean no
marks will be left on the
surface of the mirror when it
is left to dry
Rinsing the mirror
After rinse and drying the trough, empty the container into it
Rinsing the mirror
Replace the mirror and swish the water over it
Drying the mirror
Drying the mirror
Stand the mirror on its end on a towel and let it dry naturally
Collimation – Newtonian Telescopes
Collimation – Newtonian Telescopes
Why collimate?
By aligning optics as well as possible improves the performance of the
telescope. Newtonians notoriously fall out of collimation very often.
This guide describes:
• Technique for visual use only
• Using a laser collimator
Collimation – Newtonian Telescopes
Collimation – Newtonian Telescopes
Before starting…
MAKE SURE THE OPTICAL
TUBE IS HORIZONTAL
You don’t want to drop anything onto
the primary mirror!
Collimation – Newtonian Telescopes
What needs adjustment?
1) Radial position of the secondary mirror
Collimation – Newtonian Telescopes
Secondary sighting tool
A Kodak 35mm film pot
is ideal for this purpose!
Collimation – Newtonian Telescopes
What needs adjustment?
• Insertion of the secondary mirror
• Orientation of the secondary mirror
Left image shows an insertion and orientation adjustment is
required. Right image shows the correct position.
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the secondary
Centre spot on primary is required
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the secondary
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the secondary
Collimation – Newtonian Telescopes
What needs adjustment?
• Introducing the Laser Collimator
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the secondary
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the secondary
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the secondary
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the secondary
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the primary mirror
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the primary mirror
Adjustment screws
Locking screws
Collimation – Newtonian Telescopes
What needs adjustment?
• Collimation of the primary mirror
Collimation – Newtonian Telescopes
In summary:
• Generally, only the use of the laser collimator is
required
• That means collimating the secondary & primary
mirrors only
• Generally, I find the secondary needs most attention
• The process takes 1 -2 minutes
Digital Setting Circles
• They aid rapid pointing of the telescope and to allow the
user know where the telescope is pointing
• This set-up is a Push-To arrangement
• Encoders are placed on each axis
• Encoders are connected an interface box
• The interface box is then connected to a computer
• Software on the computer, say a planetarium program,
gives the user access to a database of objects to find, etc.
Digital Setting Circles
The Altitude Encoder
Digital Setting Circles
The Azimuth Encoder
Digital Setting Circles
The Interface Box
The Dave Ek Digital Setting Circles printed circuit board - $24.00
Digital Setting Circles
The Interface Box
Digital Setting Circles
The Interface Box
Digital Setting Circles
The Interface Box
Digital Setting Circles
The Interface Box
Digital Setting Circles
The Interface Box connected to a PC serial port
Digital Setting Circles
The Interface Box connected to a Bluetooth serial adapter
Digital Setting Circles
Software – Android Smart Phone
• Sky Safari Plus (cost ~£8.00)
• Massive database of different types of
objects
• Contains 2.5 million stars – excellent
for zooming in to see the star filed as
seen in the eyepiece – makes
spotting the object more easy.
• Easy telescope control using
Digital Setting Circles
Software – PC Planetarium
• The software which use ASCOM drivers will work
• Sky Map Pro does
Digital Setting Circles
Digital Setting Circles
The End