Meade Instruments Lightbridge Plus User Manual

Instruction Manual

LightBridge™ Plus Truss Tube

Dobsonian Telescopes

WARNING!

Never use an unfiltered telescope to look at the Sun! Looking at or near the Sun will cause instant and irreversible damage to your eye. Eye damage is often painless, so there is no warning to the observer that damage has occurred until it is too late. Do not point the telescope at or near the Sun. Do not look through the telescope or Viewfinder as it is moving. Children should always have adult supervision while observing.

CONTENTS

LightBridge Plus features...........................................................................................4

Focuser assembly................................................................................................5

Primary mirror assembly.......................................................................................5

Azimuth bearing assembly....................................................................................5

Secondary mirror assembly..................................................................................5

Assembling the base................................................................................................. 6

Assembling the optical tube.......................................................................................7

The red-dot finder.......................................................................................................9

The cooling fan.........................................................................................................10

Collimation of the optical system..............................................................................10

Simplified collimation...........................................................................................10

Enhanced collimation.........................................................................................12

Aligning the red-dot finder........................................................................................13

Using the Dobsonian telescope................................................................................13

Calculating magnification.........................................................................................14

Observing.................................................................................................................14

Some tips.................................................................................................................17

Care of the optics......................................................................................................18

Specifications...........................................................................................................19

10” LightBridge Plus..........................................................................................19

12” LightBridge Plus..........................................................................................20

16” LightBridge Plus..........................................................................................21

Optional accessories................................................................................................22

The reflector optical system......................................................................................23

Meade customer service.........................................................................................24

Meade limited warranty...........................................................................................24

Observing Log.....................................................................................................25-27

Social media and address.........................................................................Back Cover

FIGURE 1: LIGHTBRIDGE PLUS FEATURES

TELESCOPE FEATURES

1. Eyepiece

2. Red-dot finder

3. Red-dot finder bracket

4. Focuser assembly

5. Upper cage

6. Upper truss tube lock knobs (3)

7. Trusses (3)

8. Lower truss tube lock knobs (3)

9. Lower cage

10. Altitude bearing (2)

11. Primary mirror cover

12. Side base panels (2)

13. Front base panel

14. Rear base panel

15. Base panel thumbscrews (12)

16. Base bottom panels (2)

17. Integrated carry handles

18. Eyepiece storage

19. Altitude brake

20. Feet (3)

21. Seam

22. Battery box

(not visible)

FIGURE 2: FOCUSER ASSEMBLY

23. Coarse focus knob

24. Fine focus knob

25. Tension knob

26. Focuser draw tube

27. 2” to 1.25” eyepiece adapter

28. Eyepiece lock thumbscrew (1.25” & 2”)

FIGURE 4: AZIMUTH BEARING ASSEMBLY

29. Center bearing bushing

30. Large roller bearing plates (2)

31. Larger roller bearing

32. Small roller bearing

33. Washers (3)

34. Adjustment bolt

(not visible)

FIGURE 3: PRIMARY MIRROR ASSEMBLY

35. Parabolic primary mirror

36. Collimation adjustment knobs (with springs)

37. Collimation lock knobs (without springs)

38. Fan

39. Fan power connector

FIGURE 5: SECONDARY MIRROR ASSEMBLY

40. Secondary mirror

41. Collimation adjustment screws (3)

42. Vertical adjustment

43. Spider vane

44. Spider vane centering nuts(4)

ASSEMBLING THE BASE Note: The Light Bridge Plus telescope does not

require any special tools to assemble. Please follow the directions closely when assembling and disassembling the telescope. The base supports the telescope and allows you to move the telescope from side to side.

Note: Numbers in parentheses. e.g., (9), refer to Figures.1 - 5.

Step 1:

Attach the three feet to the bottom panel (20). Locate the bottom panel which has three threaded holes and thread in each foot into the holes until firm.

Step 3:

Place the center bearing bushing (29) into the countersunk hole on the top side of the base bottom panel (16). Slide one of the large roller bearing plates (30) over the center bushing (29) followed by the large roller bearing (31).Place the remaining bearing plate (30) on top of the roller bearing (29). Lastly, place the top panel (16) onto the center busing. The correct orientation of the top panel is with the six threaded holes facing up. See Figure 4.

Top side of bottom panel

Center

bushing

Base feet

Bottom side of bottom panel

Base feet

Figure 6

Step 2:

Locate the included hardware pack and set aside the following:

1. Center bearing bushing (29).

2. Two large bearing plates (30) and large needle bearing (31).

3. Small needle bearing (32) with two small and one large washer (33).

4. Azimuth adjustment knob (34)

Adjustment Knob

Small washer

Small needle bearing

Small washer

Large washer

Figure 7

Large

needle

bearing

Figure 8

Bearing plates above and below bearing

Step 4:

To secure the azimuth bearing system in place: On the adjustment knob bolt (34), place one small washer (33) on both sides of the small needle bearing (32) followed by the large washer. Slide the adjustment bolt (34) through the top base panel (16) and into the center bushing (29) and hand-tighten. A threaded nut is pre-installed on the bottom plate.

Step 5:

Rotate the circular base panels (16). They should move smoothly and easily without any stiffness. If not, check to make sure the parts were assembled in the correct order and there is nothing preventing the base from rotating freely.

Step 6:

Locate the six pre-drilled holes on the topside of the upper most panel (16). The six holes form a “U” shape and are used to mount the side (12) and front base panels (13) into position.

Step 7:

Locate all 12 base thumbscrews (15) and all four base panels (12-14). Place one of the large side walls (12) onto the base with the LightBridge Plus logo facing outward.

Use two of the thumbscrews (15) to mount the side panel onto the bottom panel. Do not firmly tighten the screws until all the panels have been assembled and loosely connected with the thumbscrews to ensure a proper fit of the panels.

Install side panels

correct tray orientation is with the screws placed under the tray and out of view.

Install eyepiece tray

Eyepiece tray

Mounting screws

Figure 11

Figure 9

Step 8:

Using the thumbscrews (15) attach the front (13) and remaining side panels (12) to the bottom panel keeping the thumbscrews slightly loose.

Step 9:

Place the small rear base panel (14) between the side panels (12) with the Meade logo facing outward. Now attach the side panels to each other using the included thumbscrews (15) keeping the thumbscrews loose.

Step 10:

Once all the panels are in place, tighten all thumbscrews (15) to a firm feel.

Note: It is not recommended to install the altitude brake (19) until the optical tube lower cage (9) is placed onto the base.

ASSEMBLING THE OPTICAL TUBE

The optical tube is the heart of the telescope and allows distant objects to be viewed up close and in impressive detail. The optical tube is a trusstube design where an A-frame structure connects the top and bottom parts of the optical tube. To assemble, closely follow the steps below.

Step 1:

Place the lower cage (9) into the base making sure that the altitude bearings (10) fit snugly into the openings on the base side panels. Make sure that the seam (21) of the tube is pointing toward the front base panel (13).

Assembled base

Figure 10

Step 11:

Attach the eyepiece storage tray in place using the two small thumbscrews provided with the tray. The

Install lower cage

Figure 12

Step 2:

Loosen the three bottom truss-tube lock knobs (8). Place each truss (7) into a set of slots. Lightly

tighten the truss knobs after all three trusses are in place.

Note: Do not fully tighten the truss-tube lock knobs (8) until the upper cage (5) is assembled to ensure all components fit together correctly.

Optical tube fully assembled

Install truss tubes

Figure 13

Step 3:

After all 3 trusses are in place, loosen the upper truss-tube lock knobs (6) on top of each truss.

Truss tubes installed

Figure 15

Step 5:

Attach the altitude brake (19) to the left base side panel (12) using the thumbscrew and brake parts provided. The altitude brake can be adjusted as needed to induce additional friction on the altitude motion.

Install altitude brake

Figure 16

Figure 14

Place the upper cage (5) into the slots at the top of each truss and lightly tighten the truss knobs (6).

Note: Make sure that the seam on the tube is also pointing towards the front panel (see step 1) otherwise the placement of the eyepiece will be in an unacceptable location.

Step 4:

With the upper and lower cages assembled, tighten all six truss-tube lock knobs (8) until firm.

Note: When using heavy eyepieces or accessories, the optical tube balance point changes and may cause the optical tube to drift downward. Tighten the altitude brake (19) to prevent the optical tube from drifting as needed. Do not fully lock the brake where the optical tube can not be easily moved or following stars in the night sky will be difficult.

Before removing or assembling the optical tube, always loosen the altitude brake fully to prevent damage by the altitude bearing (10).

The entire assembly should move easily up and down and from side to side.

Step 6:

Insert the two inch eyepiece (1) into the focuser assembly and tighten the 2” eyepiece lock thumbscrew (28).

If the 2” to 1.25” eyepiece adapter (27) is

installed, remove it by loosening the eyepiece lock thumbscrews (28) and pulling the adapter out. Set it aside for later use.

To focus the eyepiece, turn the coarse focus knob (23) until the viewed object is in focus. The LightBridge Plus telescope come with a 10:1 fine focus knob that can be used to get your final focus (24) with more precision.

Remove primary mirror cover

Note: It may be necessary to use the included 2” Extension tube in order to achieve focus. Meade includes this 2” extension tube to allow a wide range of eyepieces to be used with the LightBridge Plus. If when using the telescope you can not achieve focus on a distant target, remove the eyepiece and insert the 2” extension tube directly into the focuser. Then insert the desired eyepiece and adjust focus until the image is sharp.

The focuser has a tension adjustment knob (25). This knob can be adjusted to get the ideal feel when turning the focuser knobs and fully tightened to lock the focuser draw tube into position and preventing it from moving in and out. When using heavy eyepieces or accessories it may be necessary to adjust this knob to prevent the focuser draw tube from changing position under the heavy accessory weight.

Figure 18

THE RED-DOT FINDER

A red dot finder has no magnification and projects a red dot in place of cross-hairs to make it easier to line up the optical tube more precisely with a target. When locating targets, always find them with the red dot first, then look into the eyepiece.

First, assemble the red dot finder. Loosen the two hex head screws on the left side of the finder using the supplied Allen wrench.

Slide the bracket into the groove at the bottom of the red dot finder and secure the two hex head screws to secure the bracket in place. The proper bracket orientation is with the flat side of the bracket facing forward and placed below the red dot viewing window.

Eyepiece

Extension Tube (if needed)

Figure 17

Focuser Tension

Knob

Experiment with these knobs to discover which adjustments are comfortable with your viewing style.

Step 7:

Lift to remove the dust cover from the primary mirror (11) and set it aside for later use.

Note: The red dot viewing window is protected by a slip-on rubber cover. Remove the rubber cover before use.

Slide the red dot finder (2) into the mounting bracket (3) on the top upper cage (5). Slide it in from the top (it will only go into the slot from this end). Tighten the thumbscrew to hold the red dot bracket securely in place.

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