Review Required (currently two divergent measurements)

This has to do with the missing hard stops at the min or max positions and is related to the 2" Crayford focuser that uses a smooth coupling between the EAF motor and the focuser shaft, as compared to other focusers using  of a rack and pinion design.

Characteristics of the Crayford focuser:

As a consequence of the Crayford design, the focuser shaft (drawtube) must be locked after an initial autofocus run as the shaft might slide out of focus with heavier cameras or equipment attached to the focuser. Also later autofocus runs must be avoided after the focuser shaft was locked manually.

Also the first EAF GoTo to the approximate optimal focuser position for a specific configuration should always start from a safe zero position (EAF current step position = 0) to avoid impressions.

On the other hand: Crayford focusers have the advantage of showing no backslash at all.

Optimal EAF Focuser Start Positions for the Main Camera

EAF Focuser Range on TSO 203/1624 Telescope

Focuser Gear Ratio (EAF)

• 442.14 EAF steps / mm (or 438,14 steps/mm as per 20230693)
• or 0.00226  mm / step (or 0,0022823 mm/step measured)

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