Replacing lubricants

Less is more? Or the more the better? Why mechanically demanding telescopes and mounts need to be properly lubricated.

You would expect implicitly that mechanically sophisticated instruments are lubricated in such a way that, within the expected operating temperature range of between –5°C and +30°C, they do their job without complaint. Unfortunately, this is not always the case: the honey-yellow grease used by Chinese manufacturers can harden at temperatures below 10°C and often causes problems. It is to be found, for example, on eyepiece rack and pinion drives, bearings and mount gears. Often, you cannot avoid completely dismantling the unit if you want to get rid of it and replace it with high-quality grease. The grease can then be removed with solvents such as cleaning solvent, isopropanol or simply brake cleaner – but be careful: metals of course will not be damaged, but painted finishes and plastic must be protected. Isopropanol in particular can permanently soften plastics containing plasticisers, even if the plastic only came into contact with it for a short time.

Suitable replacement lubricants include Teflon grease or lithium grease with a wide temperature range. If plastic gears are to be lubricated, it is important to ensure that the grease is compatible with them. To apply grease in the right quantities in hard-to-reach spots, we recommend that you draw the grease into a syringe and then apply it through a nozzle. You can try different sizes of nozzle to suit the consistency of the grease.

Author: Sven Wienstein / Licence: Oculum Verlag GmbH