ORION TELESCOPES & BINOCULARS Tabletop Equatorial Mount 9009, 9009 Instruction Manual

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INSTRUCTION MANUAL

Orion

Tabletop Equatorial Mount

#9009

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Figure 1. The Tabletop Equatorial Mount

Counterweight

Counterweight shaft

R.A. slow-motion control cable

Counterweight lock thumb screw

Tr ipod leg

Latitude

lock knob

Azimuth

lock lever

Dec. slow-motion

control cable

R.A. lock lever

Dec. lock lever

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1. Parts List

Qty. Description 1 German-type equatorial mount 2 Slow-motion control cables 1 Counterweight 1 Counterweight shaft 3 Tripod legs

2. Assembly

Carefully remove all of the items from the shipping box. Make sure all the parts listed in Section 1 are present. Save the boxes and packaging material. In the unlikely event that you need to return the mount, you must use the original packaging.

Assembling the mount for the first time should take about 5 minutes. No tools are needed. Refer to Figure 1 during the assembly process.

1.La y the equatorial mount on its side.Attach the tripod legs, one at a time, by threading them into the holes at the base of the mount.

2. With the tr ipod legs now attached to the equatorial mount, stand the mount upright.

3. Orient the mount as it appears in Figure 2, at a latitude of about 40°, i.e., so that the pointer next to the latitude scale is pointing to the hash mark at “40.”

To do this, loosen the latitude lock knob (below the lati-

tude scale), and adjust the latitude of the mount until the pointer and the “40” line up.Then re-tighten the latitude lock knob.You may also need to rotate the mount about its right ascension (R.A.) and declination (Dec.) axes. Do this by first loosening the R.A.and Dec.lock levers.

4.Slide the counterweight onto the counterweight shaft. Make sure the counterweight lock thumb screw is adequately loosened so the counterweight shaft can pass through the hole in the counterweight. Position the counterweight about halfway up the shaft and tighten the counterweight lock thumb screw. The washer and screw on the end of the counterweight

ongratulations on your purchase of a quality Orion product.

Your new Tabletop Equatorial Mount is extremely portable and can be conveniently taken with you wherever you go to observe. A quickrelease mounting system allows fast and easy attachment of a wide variety of different telescope optical tubes. With its precision yet highly portable equatorial head, you’ll be able to easily track astronomical objects over time so that they remain within your eyepiece’s field of view. The setting circles will help locate hundreds of fascinating celestial denizens, including galaxies, nebulas, and star clusters.With a little practice and a little patience, you’ll find that your Tabletop Equatorial Mount is an invaluable tool for getting the most out of your astronomical observing sessions.

These instructions will help you set up and properly use your equatorial mount. Please read them over thoroughly before getting started.

Table of Contents

1. Parts List ................................................................................................................................ 3

2. Assembly ............................................................................................................................... 3

3. Attaching A Telescope ........................................................................................................... 4

4. Balancing the Telescope........................................................................................................ 5

5. Adjusting Height .................................................................................................................... 5

6. Aligning and Using the Equator ial Mount.............................................................................. 5

7. Specifications....................................................................................................................... 10

R.A. axis

Dec. axis

Dec. lock lever

Dec. setting circle

R.A. slowmotion control cable

R.A. worm gear shaft

R.A. setting

circle

Dec. worm

gear shaft

Dec.

slow-motion

control cable

R.A. lock lever

Latitude

lock knob Latitude scale

Figure 2: Close up of the equatorial mount

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shaft will prevent the counterweight from slipping off the shaft and possibly onto your foot if the counterweight lock thumb screw should come loose.

5. Thread the counterweight shaft with counterweight attached into the equatorial mount at the base of the declination axis. Before a telescope is attached to the mount, make sure the counterweight is oriented directly over a tripod leg, as shown in Figure 1. Otherwise, the mount will tip over.To orient the counterweight relative to the tripod legs, loosen the azimuth lock lever and rotate the mount left-to-right on the tripod. When properly oriented, retighten the azimuth lock lever.

6. Now attach the two slow-motion control cables to the R.A. and Dec. worm gear shafts (see Figure 2) of the equatorial mount by positioning the thumb screw on the end of the cable over the indented slot on the shaft, then tightening the thumb screw .For the Dec.axis, attach the cable to the longer end of the Dec. worm gear shaft. A cable can be attached to either end of the R.A. worm gear shaft, whichever is most convenient for you.

3. Attaching a Telescope

The Tabletop Equatorial Mount is designed to hold small to mid-size telescopes weighing up to about 7 lbs. For heavier telescopes, the mount may not provide sufficient stability for steady imaging. Many types of telescopes can be mounted on the Tabletop Equatorial Mount, including refractors and catadioptrics, provided the telescope has a 1/4"-20 mounting block. 35mm cameras can also be attached to the mount.

To connect your telescope to the Tabletop Equatorial Mount, you must remove the mount's quick-release mounting plate. Disengage the quick-release lever, and pull the plate off the top of the mount. Grip the plate by its threaded stud to do this (see Figure 3).

Now, attach the plate to your telescope by threading the stud into the telescope's 1/4"-20 mounting block. You can use a flat-head screwdriver in the slotted screw head on the underside of the mounting plate to firmly secure the plate to the telescope. Orient the plate so the telescope is perpendicular to the slots on the edge of the mounting plate (see Figure 4).

Replace the mounting plate, with telescope attached, to the top of the equatorial mount. Register the slots in the edges of the plate with the mating feature on the mount's top (see Figure 5). Once the plate is seated in its proper position, re-engage the quick-release lever.

For transporting and storing your telescope, it is an easy matter to remove the telescope from the mount. Simply disengage the quick-release lever, and pull the telescope (with mounting plate attached) from the mount.

quick-release lever

quick-

release

mounting

plate

slot in edge of mounting plate

Figure 3:To remove the quick-release mounting

plate, disengage the quick-release lever and

grip the threaded stud.

Figure 4: Or ient the mounting plate so thatthe edge

slots are perpendicular to the telescope tube.

Figure 5: The edge slots on the mounting plate

edge slot

mating feature on mount’s top

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4. Balancing the Telescope

Once the telescope is attached to the equatorial mount, the next step is to balance the telescope about the mount's R.A. axis. Proper balance is required to insure smooth movement of the telescope on the equatorial mount.

Keeping one hand on the telescope optical tube, loosen the R.A. lock lever. Make sure the Dec. lock lever is locked. The telescope should now be able to rotate freely about the R.A. axis. Rotate it until the counterweight shaft is parallel to the ground (i.e., horizontal).

Now loosen the counterweight lock thumb screw and slide the weight along the shaft until it exactly counterbalances the telescope (see Figure 6a). That’s the point at which the shaft remains horizontal even when you let go of the telescope with both hands (see Figure 6b). Retighten the counterweight lock thumb screw. The telescope is now balanced on the R.A. axis.

It is not possible to adjust the telescope's balance about the Dec. axis of the mount. Usually, the telescope will be balanced naturally about the Dec. axis due to the manufacturer's placement of the 1/4"-20 mounting block at the balance point of the telescope.

Now that the telescope is properly balanced, when you loosen the lock lever on one or both axes and manually point the telescope, it should move without resistance and should not drift from where you point it.

5. Adjusting Height

The Tabletop Equatorial Mount requires a sturdy table or platform for use.Find a platform that will place the telescope's eyepiece at a comfortable height for viewing. Typically, an outdoor picnic table will provide adequate height and stability. Other outdoor platforms, like a tree stump or large rock, can also be employed.

If you wish, you can use the equatorial mount on a standard photo-style tripod (see Figure 7). Simply remove the three supplied tripod legs from the mount, and thread the photo tripod's 1/4"-20 mounting stud into the threaded hole on the bottom of the equatorial mount casting. Lock the photo tripod's pan-head into place, and move the telescope about the R.A.and Dec.ax es of the equatorial mount only.

6. Aligning and Using the

Equatorial Mount

When you look at the night sky, you no doubt have noticed that the stars appear to move slowly from east

Figure 6a, 6b: Slide the counterweight along the

counterweight shaft until it balances the

telescope tube.

6a.

6b.

Figure 7: The Tabletop

Equatoral Mount used in conjunction with a photo-style tripod.

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to west over time. That apparent motion is caused by the Earth's rotation (from west to east). An equatorial mount is designed to compensate for that motion, allowing you to easily “track” the movement of astronomical objects, thereby keeping them from drifting out of the telescope's field of view while you're observing.

This is accomplished by slowly rotating the telescope on its right ascension axis, using only the R.A. slowmotion cable.But first the R.A. axis of the mount must be aligned with the Earth's rotational (polar) axis; this is a process called polar alignment.

Polar Alignment

For Northern Hemisphere observers, approximate polar alignment is achieved by pointing the mount's R.A. axis at the North Star, or Polaris. It lies within 1° of the north celestial pole (NCP), which is an extension of the Earth's rotational axis out into space. Stars in the Northern Hemisphere appear to revolv e around P olaris.

To find Polaris in the sky, look north and locate the pattern of the Big Dipper (Figure 8). The two stars at the end of the “bowl”of the Big Dipper point right to Polaris.

For general visual observation, an approximate polar alignment is sufficient:

1. Loosen the latitude lock knob.Tilt the mount until the pointer on the latitude scale is set at the latitude of your observing site. If you don't know your latitude,

consult a geographical atlas to find it. For example, if your latitude is 35° Nor th, set the pointer to +35 (see Figure 9).Then retighten the latitude lock knob. The latitude setting should not have to be adjusted again unless you move to a different viewing location some distance away.

2. Loosen the Dec. lock lever and rotate the telescope optical tube until it is parallel with the R.A. axis (see Figure 10). The pointer on the Dec. setting circle should read 90°. Retighten the Dec. lock lever.

The two stars at the end of the "bowl" of the Big Dipper point to Polaris.

Figure 8. Finding Polaris

Big Dipper

(in Ursa Major)

Little Dipper

(in Ursa Minor)

N.C.P.

Pointer Stars

Cassiopeia

Polaris

latitude

scale

latitude

lock

knob

indicator arrow

Figure 9: Adjust the tilt of the mount until the arrow

indicates your latitude on the latitude scale.Each

mark on the scale represents 5° increments.

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3. Loosen the azimuth adjustment lever and rotate the entire equatorial mount left-to-right so the telescope tube (and R.A. axis) points roughly at Polaris.If you cannot see Polaris directly from your observing site,

consult a compass and rotate the equatorial mount so the telescope points North. Retighten the azimuth adjustment lever.

The equatorial mount is now polar aligned for casual observing. From this point on in your observing session, you should not make any further adjustments to the azimuth or the latitude of the mount, nor should you mov e the tripod.Doing so will undo the polar alignment.The telescope should be moved only about its R.A.and Dec.axes.

Use of the R.A. and Dec. Slow-Motion Control Cables

The R.A. and Dec. slow-motion control cables allow fine adjustment of the telescope's position to center objects within the field of view. Before you can use the cables, you must manually “slew” the mount to point the telescope in the vicinity of the desired target. Do this by loosening the R.A. and Dec. lock levers and moving the telescope about the mount's R.A. and Dec. axes. Once the telescope is pointed somewhere close to the object to be viewed, retighten the mount's R.A. and Dec. lock levers.

The object should now be visible somewhere in the telescope's (aligned) finder scope. If it isn't, use the slow-motion controls to scan the surrounding area of sky. If the object is still not visible in the finder scope, you will need to slew the mount again, this time being more careful to point the telescope closer to what you wish to view.

When the object is visible in the finder scope, use the slow-motion controls to center it.Now, look in the telescope with a long focal length (low magnification)

eyepiece. If the finder scope is properly aligned, the object should be visible somewhere in the field of view. If it is not, you may need to realign the telescope's finder scope.

Once the object is visible in the telescope's eyepiece, use the slow-motion controls to center it in the field of view.You can now switch to a higher magnification eyepiece, if you wish. After switching eyepieces, you can use the slow-motion control cables to re-center the image, if necessary.

The Dec. slow-motion control cable can move the telescope a maximum of 25°. This is because the Dec. slow-motion mechanism has a limited range of mechanical travel. (The R.A. slow-motion mechanism has no limit to its amount of travel.) If you can no longer rotate the Dec. control cable in a desired direction, you have reached the end of travel, and the slow-motion mechanism should be reset. This is done by first rotating the control cable several turns in the opposite direction from which it was originally being turned. Then, manually slew the telescope closer to the object you wish to observe (remember to first loosen the Dec.lock lever).You should now be able to use the Dec. slow-motion control cable again to fine adjust the telescope's position.

Tracking Celestial Objects

When you observe a celestial object through the telescope, you'll see it drift slowly across the field of view. To keep it in the field, if your equatorial mount is polaraligned, just rotate the R.A. slow-motion control. The Dec. slow-motion control is not needed for tracking. Objects will appear to move faster at higher magnifications, because the field of view is narrower.

Understanding the Setting Circles

The setting circles on an equatorial mount enable you to locate celestial objects by their “celestial coordinates.” Every astronomical object resides in a specific location on the “celestial sphere.”That location is denoted by two numbers: its right ascension (R.A.) and declination (Dec.). In the same way, every location on Earth can be described by its longitude and latitude. R.A. is similar to longitude on Earth, and Dec. is similar to latitude. The R.A. and Dec. values for celestial objects can be found in any star atlas or star catalog.

So, the coordinates for the Orion Nebula listed in a star atlas will look like this:

R.A. 5h 35.4m Dec. -5° 27'

R.A. axis

Figure 10:

Loosen the Dec. lock lever and rotate the telescope tube until it is parallel with the R.A. axis.

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That's 5 hours and 35.4 minutes in right ascension, and

-5 degrees and 27 arc-minutes in declination (the negative sign denotes south of the celestial equator). There are 60 minutes in 1 hour of R.A and there are 60 arcminutes in 1 degree of declination.

The mount’s R.A. setting circle is scaled in hours, from 1 through 24, with small hash marks in between representing 20 minute increments.The Dec. setting circle is scaled in degrees, with each small hash mark representing 2.5°.

Before you can use the setting circles to locate objects, the mount must be well polar aligned, and the setting circles must be calibrated.The declination setting circle was calibrated at the factory, and should read 90° when the telescope optical tube is parallel with the R.A. axis. The R.A. setting circle needs to be calibrated before each observing session.

Calibrating the Right Ascension Setting Circle

1. Identify a bright star near the celestial equator and look up its coordinates in a star atlas.

2. Loosen the R.A.and Dec.lock levers on the equatorial mount, so the telescope optical tube can move freely.

3 Point the telescope at the bright star near the celes-

tial equator whose coordinates you know. Center the star in the telescope's field of view. Lock the R.A.and Dec. lock levers.

4. There are three indicator arrows for the R.A. setting circle. Choose one that is most conveniently positioned for easy visual reference, and rotate the R.A. setting circle so the arrow indicates the R.A. coordinate listed for the bright star in the star atlas (see Figure 11). Refer only to the chosen indicator arrow when subsequently using the R.A. setting circle to find objects.

Finding Objects With the Setting Circles

Now that both setting circles are calibrated, look up in a star atlas the coordinates of an object you wish to view.

1. Loosen the Dec. lock lever and rotate the telescope until the value pointed to by the Dec. setting circle indicator arrow matches the Dec.coordinate from the star atlas. Retighten the lock lever.

Note: If the telescope is aimed south and the Dec.setting circle indicator arrow passes the 0° mark, the value on the Dec. setting circle becomes a negative number.

2. Loosen the R.A.lock lever and rotate the telescope until

the value pointed to by the R.A. setting circle indicator arrow matches the R.A.coordinate from the star atlas.

Most setting circles are not accurate enough to put an object dead-center in your finder scope's field of view, but they'll get you close, assuming the equatorial mount

is accurately polar aligned. The R.A. setting circle should be re-calibrated ever y time you wish to locate a new object.Do so by calibrating the setting circle for the centered object before moving on to the next one.

Confused About Pointing Your Telescope?

Beginners occasionally experience some confusion about how to point their telescope overhead or in other directions. In Figure 10, the telescope is pointed north as it would be during polar alignment. The counterweight shaft is oriented downward.But it will not look like that when the telescope is pointed in other directions. Let’s say you want to view an object that is directly overhead, at the zenith. How do you do it?

One thing you DO NOT do is mak e any adjustment to the mount's latitude (tilt).That will nullify the polar alignment. Remember, once the mount is polar aligned, the telescope should be moved only on the R.A.and Dec.axes. To point the scope overhead, first loosen the R.A. lock lever and rotate the telescope on the R.A. axis until the counterweight shaft is horizontal (parallel to the ground). Then loosen the Dec. lock lever and rotate the telescope until it is pointing straight overhead (See Figure 12).The counterweight shaft is still horizontal.Then retighten both lock levers.

Figure 11: Rotate the R.A. setting circle until the

chosen indicator arrow points to the R.A. coordinate of

the alignment star.Only one of the three indicator

arrows is shown.

R.A.

setting

circle

indicator arrow

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Similarly, to point the telescope directly south, the counterweight shaft should again be horizontal. Then you simply rotate the scope on the Dec. axis until it points in the south direction. (Figure 13a).

What if you need to aim the telescope directly north, but at an object that is nearer to the horizon than Polaris? You can’t do it with the counterweight down as pictured in Figure 10.Again, you have to rotate the scope in R.A. so that the counterweight shaft is positioned horizontally. Then rotate the scope in Dec. so it points to where you want it near the horizon.(Figure 13b)

To point the telescope to the east (Figure 13c) or west (Figure 13d), or in other directions, you rotate the telescope on its R.A. and Dec. axes. Depending on the altitude of the object you want to observe, the counterweight shaft will be oriented somewhere between vertical and horizontal.

The key things to remember when pointing the telescope is that a) you only move it in R.A.and Dec., not in azimuth or latitude (altitude), and b) the counterweight and shaft will not always appear as it does in Figure 10. In fact it almost never will!

Figure 12: The mount is positioned as it would be if attempting to observe at the zenith.

Figure 13a, 13b, 13c, 13d:

The Tabletop Equatorial Mount with a telescope pointing (a.) south, (b.) north, (c.) east, and (d.) west.

13d.

13c.

13b.

13a.

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7. Specifications

Mount: German-type equatorial Tripod: aluminum

Height: 13" Weight: 9.8 lbs Counterweight: 5.0 lbs Maximum Loading Weight: about 7 lbs Slow-Motion Adjustment: both RA and Dec axes Setting Circles: RA scaled in 20 min. increments, Dec

scaled in 2.5° increments Polar Axis Altitude Adjustment:15° to 90°

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One-Year Limited Warranty

This Orion Tabletop Equatorial Mount is warranted against defects in materials or workmanship for a period of one year from the date of purchase.This warranty is for the benefit of the original retail purchaser only. During this warranty period Orion Telescopes & Binoculars will repair or replace, at Orion’s option, any warranted instrument that proves to be defective, provided it is returned postage paid to: Orion Warranty Repair, 89 Hangar Way, Watsonville, CA 95076. If the product is not registered, proof of purchase (such as a copy of the original invoice) is required.

This warranty does not apply if, in Orion’s judgment, the instrument has been abused, mishandled, or modified, nor does it apply to normal wear and tear.This warranty gives you specific legal rights, and you may also ha ve other rights, which vary from state to state.F or further warranty service information, contact: Customer Service Department, Orion Telescopes & Binoculars, P. O.Box 1815, Santa Cruz, CA 95061; (800) 676-1343.

Orion Telescopes & Binoculars

Post Office Box 1815, Santa Cruz, CA 95061

Customer Support Help Line (800) 676-1343 • Day or Evening