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
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
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
Stand the mirror on its end on a towel and let it dry naturally
Collimation – Newtonian Telescopes
This guide describes: Technique for visual use only Using a laser collimator Why collimate? By aligning optics as well as possible improves the performance of the telescope. Newtonians notoriously fall out of collimation very often.
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
The End