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What to check nightly, monthly and yearly

Equipment degrades slowly and fails suddenly. Three short routines at three intervals catch almost everything before it costs an evening.

Three intervals, none of them long.

Every session, before carrying anything out

Caps on, cell in the finder, the eyepieces you intend to use in the case. Put the telescope outside as early as you can — cool-down is the free improvement most often skipped.

Every session, afterwards

Let everything dry before capping and boxing it. A tube brought in dewed and closed immediately holds that moisture against the optics for hours.

Monthly, in daylight

Check the collimation. Check the finder alignment on a distant fixed object. Tighten the screws that hold the finder bracket, the dovetail and the tube rings — all of them loosen with handling.

Yearly, before the long nights

Replace the coin cell whether or not it works. Run the focuser through its travel feeling for roughness and sideways play. Move each mount axis with the clutches loose, feeling for tight spots. Inspect the optics under a torch and resist cleaning them unless something is genuinely on the glass.

And once, when you buy anything

Write down the fittings it needs: barrel size, thread, dovetail profile, back focus. That list is what turns the next purchase into a decision rather than a gamble.

The questions that keep arriving

Is any of this actually necessary?

The nightly one is a habit rather than maintenance. The other two catch the failures that end sessions: a dead cell, a loose finder bracket, a collimation that drifted in a car boot.

What is most often found?

Coin cells, loose screws and a collimation that has drifted. All three are five-minute fixes in daylight and evening-enders in the dark.

Last reviewed 17 September 2026