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Improving the CG-5 Equatorial Mount


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Declination Axis
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Taking a CG-5 equatorial head apart and putting it back together again requires a few basic tools and a modest set of mechanical skills. If nuts, bolts, set screws, worm gears, Allen wrenches, and retaining rings make you nervous, you may be wise to find someone else to do the job.

Tools and Materials
You will need the following items:

  • Paper and pencil. Make notes as you go along. Trust me: a set of detailed notes made during disassembly will be very helpful when you are reassembling the equatorial head. This is the most important item of advice I can offer. When I rebuilt my first CG-5, I made 10 pages of notes and sketches during disassembly.
  • Allen (hex) wrenches. Most of the screws holding the equatorial head together have hex heads and require Allen wrenches (also known as hex drivers) to remove or loosen. There are several sizes of these. Discussion with other CG-5 owners has revealed that some mounts are assembled with metric hardware, while others use English sizes. Be prepared for either type.
  • Small slotted screw driver. There are a few tiny slotted screws for which a suitable screwdriver is required.
  • Sharpening stone. To smooth and deburr some of the metal parts, I used a sharpening stone. One suitable type is a so-called "Arkansas" stone.
  • Crocus cloth. This is a cloth-backed abrasive sheet, similar to sandpaper, but much finer. It can be found in the sandpaper section of a good hardware store or home center. You will need the Crocus cloth (along with the sharpening stone) to smooth and polish the internal metal parts of the equatorial head.
    Although I used crocus cloth, extremely fine grit sandpaper will also work. Some rebuilders have reported good results through wet sanding with a very fine grit sandpaper.
  • Utility knife. I used a sharp, flat bladed knife to scrape rough spots off the many plastic washers inside the equatorial head.
  • Cleaning solvent. You'll need a solvent to dissolve the old grease from the moving parts of the mount. I used 100% mineral spirits, sometimes sold as paint thinner. If you have a favorite solvent for cleaning greasy parts, by all means use it. One CG-5 owner recommends diesel fuel. NOTE: Mineral spirits can be hazardous to your health. Please follow the label warnings regarding ventilation, skin/eye contact, and ingestion.
  • Toothbrush. This is an excellent tool for scrubbing in between gear teeth and other hard to reach places.
  • Cotton cloths. Clean, lint-free cotton cloths are a must for cleaning parts and removing excess grease and solvent – and for keeping your hands clean.
  • Grease. Once the old, sticky grease is removed, you should re-grease the equatorial head with a good quality synthetic grease. I used Quaker State Full Synthetic White Marine Grease, a lithium-containing grease purchased at my local Wal-Mart store. A mount rebuilder in the UK recommends "Weldtite" lithium grease, available from cycle shops for about £2 per tube. Also highly recommended by some is Super Lube® grease, which sounds just about perfect for this application.
  • Containers. You will want some clean jars or other containers; one to hold the cleaning solvent and others to hold small parts to prevent them from being lost.

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