Celestron 91510 Telescope Maintenance, Collimation for the #31027 and #31056 only

4.Move the telescope in R.A. using the slow motion control handle until the three on the vernier scale lines up with one of the marks on the R.A. setting circle. Remember, the R.A. indicator must stay between the 18h 50m mark and the 19h 00m mark on the R.A. setting circle!

5.Look through the telescope and the Ring Nebula should be within the field of view if you are using a low power eyepiece (assuming you have already set the DEC).

Telescope Maintenance

With proper care your telescope should rarely need any maintenance work.

1.When not in use, always replace all lens covers to keep dust and contaminants off the optical surfaces.

2.A small amount of dust on any optical surface is OK. If the dust builds up then use a can of compressed air and then a camel's hair brush to remove the dust.

3.If the mirrors or lenses need cleaning, they should be cleaned by a professional. Either have your instrument serviced by a telescope repair facility or return it to the factory.

4.Collimation or alignment of the optical system is done at the factory before shipment.

Collimation (for the #31027 and #31056 only)

1.If your telescope has received very rough handling during transport or is dropped, it may need collimation.

To check if your telescope is in collimation the sketch below will help you. If you look into the eyepiece adapter (without an eyepiece), this is what you should see. If the reflection of your eye is off center, then collimation is necessary.

2.If your telescope is out of collimation, it can be re-collimated by loosening the three Phillips head screws located on the rear cell of the telescope tube and adjusting the three knurled knobs until the secondary mirror is centered in the reflection of the primary mirror.

14