A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tony Oz
Date: 2017 Jun 2, 02:06 -0700
Thank you for the clarification. I sort of understand now how this mechanical integrator works. If the roller is not tilted - the track it draws on the spindle is a straight line and no spindle rotation occurs. If the roller is tilted - its' track on the spindle becomes a spiral, the more tilt - the more tight that spiral is. By the end of the integration interval the spindle is found at some angle (or a number of turns) from its' initial zero position.
Regarding my question why the clutch is engageable only at integer drum degrees, what if I have to start with a half-degree drum setting: this is intentional. With the integrator cartridge not moving (under the roller) - no drum movements are reflected onto the integrator's degrees/minutes scales. The mid-degree drum's position will be reflected in the integrator only by the end of the interval. If I start with a half-degree value on the drum - that half-degree will accumulate in the integrator by the end of the interval. So, the reading on the drum and its' vernier will (ideally) coincide with integrator's readings (taking into account the intrinsic 3° offset). This is actually the whole idea about the integrator.
That's how I understand the workings of that device.
Thank you in advance.