Orion Optics OD150 Manuel utilisateur
Owners manual for models:
OD150, OD200, OD250, OD300, OD350 and OD400
Contents
1 Introduction
2 Main parts of telescope
3. Model differences
4. Assembly
5. Checking things
. Collimation
7. Using the telescope
8. Care and Maintenance
9. Accessories and upgrades
Orion Optics UK Ltd
Thank you for buying one of our Dobsonian range of telescopes. The following will give you all the
information you need to allow you to assemble, use and, maintain your telescope. If you carry out the
procedures correctly the telescope will give you many years of faultless usage. Please take note in
particular of the details on care of optics, if these notes are ignored or not carried out properly, damage
to the optical coatings could result. Please read through this document before commencing assembly
of the telescope, familiarise yourself with the names of the major components. And finally, when
assembled, above all, enjoy it.
This section will show you the main parts of the telescope and their function within the telescope.
Nearly all the parts on all the range have the same name and function but, because of differing model
sizes, the actual shape of the part often varies.
Shown here is a typical model with most external components labelled. Certain items are shown in
greater detail.
Introduction
Main Telescope parts
TYPICAL DOB ONIAN MODEL
Fig 1
Apart from the obvious difference of aperture and physical size and shape, all the telescopes from the
OD150 up to and including the OD400, are remarkably similar. Differences occur mainly in the
technical specifications between the standard models and the de-luxe models.
The main areas of ‘visible’ differences are:
Finder scope. Standard are supplied with a 30mm aperture finder, De-Luxe with a 50mm finder
but both work off exactly the same principle.
Focuser. Standard are fitted with a rack and pinion 2” focuser (150mm models use a
31.7mm focuser) The De-Luxe utilises a 2” precision Crayford focuser.
Both the above two items are covered in more detail later.
Differences which cannot be readily seen until you begin to use the telescope:
Optics. Standard models are supplied with our normal coatings, De-Luxe models have our
hi-tech Hilux high reflectivity coatings applied to both mirrors. This typically
transmits around 25% more light to your eye than standard telescope optical
coatings. 1/4PV wavefront optics are fitted to the standard models and 1/ PV to
De-Luxe models. With the De-Luxe models, you should also have a Zygo print out
of data of the telescope on optical test.
You may have requested and had some additional equipment added to your telescope, this is not
covered in this manual.
Model differences
DOB ONIAN BA E ECTION UNA EMBLED
Fig 2
To assemble the base choose a hard, flat surface. Do not try to assemble on a carpeted or similar
surface as the mount will not fit squarely together. First of all, fix the back panel to the base assembly
with one of the assembly screws, use the supplied Allen key. DO NOT TIGHTEN the screw at this
stage. See Fig 3.
Assembly
Fig 3
Next, fix one of the side panels to the base and back panel, see Fig 4
Fig 4
Again, DO NOT TIGHTEN the screws yet. Now attach the other side panel, see Fig
Fig 5
The base is now assembled and you are about to align the 4 main sections together. This requires a
hard, flat surface. Lie the mount down on its side opposite the back panel and adjust the panels until it
lies flat on the floor. If you have tightened the screws too much it will not lie flat and you will need to
slacken them. Once the mount is lying flat, tighten gradually the screws until they are fully tight and the
mount is lying perfectly flat. Stand the mount up and you are now ready to add the telescope tube and
cradle assembly.
The easiest method of placing the telescope tube and cradles on the mount is to hold the two trunnion
bearings as you would the carrying handle on a suitcase, one in each hand. Carefully position the two
bearings directly over the top of the semi circular cut out on each of the side panels and lower the
bearings until they lie snug against the four rectangular pieces of PTFE in the cut outs. The telescope is
now ready for checking prior to use.
Fig 6
Before beginning to use the telescope there are a few things you need to check out first. This will
ensure you have a trouble free viewing session ahead of you. The fist thing to check is if the trunnion
bearings are lying snug a set square on the PTFE Alt. Bearings. On the smaller aperture models it is
unlikely you will come across a problem here but on the larger models occasionally a slight
misalignment occurs. Fig shows the location of four of the alignment screws on one side of the
trunnion bearing on larger models. These four screws, in conjunction with the four other screws shown,
will allow you to exactly align the bearings to the mount. This combination of ‘push/pull’ screws is
allowing the bearings to be slightly skewed against the hidden trunnion blocks which are inside the
trunnion bearings but unfortunately not visible. Once aligned, it will not be necessary to adjust them
again unless you completely dismantle the mount.
The next thing to check is the collimation (optical alignment) of both mirrors to the tube and each other.
Many people worry about collimation because on large, short focal length telescopes can be
sometimes difficult. However, if you follow the following, exactly, you will have no problem, probably.
If the telescope has travelled well to you, you may well still have a perfectly collimated telescope as in
Fig 7. Unfortunately most telescopes move out of alignment to varying degrees when being transported
over long distances. In those cases, you may well see something like Fig 8 or Fig 9. The secondary
mirror is slightly out in fig 8 and in f9, both mirrors are slightly out.
Not a problem:
The following is by no means a definitive description of collimating a Newtonian, neither is it the easiest
method to teach or learn. However, it has the advantages of being free, no equipment needed,
and, once learned, the principle can be applied to most telescopes. I will refer in the text to a `Polo mint'
It is the easiest method I know to refer to a particular view through the telescope when using this
procedure. For those who have lived a very sheltered life, a Polo mint is a circular white mint with a
central hole of approximately 25% of the overall mint's diameter.
Checking things
Collimation
Technical stuff!
If you can have someone to help in this procedure you will find things are resolved much, much quicker.
Procedure:
The first thing, which must be done, is to examine the telescope in daylight when positioned
horizontally (ish) and facing an even light coloured surface. In your house and pointing towards a light
painted wall or similar is ideal. If you point it to a surface which is unevenly lit, uneven colouration, or
texture, it can deceive your eyes in positional aspects.
If you can leave about 10 foot between the end of your tube and the `wall', so much the better.
Stand as far away from the end of the tube and look down it. You should see everything symmetrical.
When you position your head so as to see an even amount of inside the tube surrounding your mirror,
your eye should be blotted out with the secondary holder. Try it you will immediately see what I mean. If
you are too close to the tube this pre-test is not possible. If symmetry is not obvious the main
mirror's collimation is out. Get your ‘assistant’ to slacken just one of the nuts at the base of your mirror
cell end of the tube while you are viewing down the tube. Only ¼ turn and you will see a movement in
the annulus of inner tube/mirror/your eye relationship changing. Adjust the mirror wing nuts until you
are getting exactly the same view from each side of the mirror/tube. You will find that when you have
reached the correct position of your mirror's collimation that any view from one side of the edge of the
tube, is identical to a view at 180 degrees opposite.
Cell used on all models 300mm and larger.
Ce manuel convient aux modèles suivants
5
Table des matières
Autres manuels Orion Optics Télescope
