Drive System

The new building drive was finally installed. After the installation some adjustments were made to the drive system itself and in the telescope control system (TCS) to let the system be smoothly operated. The resulting system tracks the telescope motion very accurately, even during acceleration and deceleration, to the extent that it is has now been possible to use the linear actuator (telescope/building position encoders) measurements to prevent actual building crashes if the building power is cut, usually a consequent of the outside stair light-beam been broken (see below). The safety system was successfully checked by placing an object in path of the staircase causing an emergency stop of the building moving at the highest speed.

Some minor adjustments have been made to the system after its installation, but it has been working without any real problems. For the time being we have the old and the new system existing alongside each other to allow for a switch between the systems as fast as possible (though this is on the mechanical side still a few hours). In the end the idea is to have the new system running for some time before removing the old system completely.

A full set of spares was bought with the building drive and it is expected to last to the end of the lifetime of the telescope (and beyond).

Thomas Augusteijn 2010-11-19