INFICON SRT-422 Crucible Indexer - Manual (Page 27)

Operation Page 25
Section 2.11: Rotation speed and torque selection for pocket seeking
The SRT-422 provides the ability to select between three speed/torque relationships by
configuring the internal DIP switches. There is a four to one gear reduction within the source,
which produces the reduced speed and increased torque at the Hearth.
Rotation Speed Rotation Torque
Setting Indexer Hearth Indexer Hearth*
High Speed 9.25 rpm 2.31 rpm 120 In-oz. 480 In-oz.
Mid Speed 7.0 rpm 1.75 rpm 156 In-oz. 625 In-oz.
Low Speed 5.0 rpm 1.25 rpm 180 In-oz. 720 In-oz.
Table 2.3: Rotation Speed and Torque
The high speed/low torque setting is desired when you want the indexer to get to the
next pocket as soon as possible, or when you want the indexer to stop rotating in the event
that evaporant material build up is starting to causing mechanical interference between the
hearth and the cover. The low speed/high torque setting may be desired when the drive
feedthrough mechanism is producing a lot or resistance to rotation. It is also desirable when
you do not want the indexer to stop rotation (i.e. during a process sequence) in the event that
the evaporant material build up is starting to cause mechanical interference between the
hearth and the cover. In any case, if a significant amount or resistance is created by either
excessive material build-up or improperly aligned drive components, the indexer will stop
rotating and signal a stall. If a stall occurs, the pocket-position LED flashes between zero and
the number of the current pocket position. A stall can occasionally be cleared temporarily by
cycling power to the indexer, however the cause of the stall should be addressed as soon as
possible. Changing the speed torque setting affects the torque and speed when the indexer is
seeking out a new pocket, however it does not affect the speed or torque when oscillating
within a banana pocket or while in the continuous-rotation mode. While using these modes,
the torque will be greater than 180 in-oz (at the indexer) due to the slow rotation speeds.
*The value for rotation torque at the hearth in the table above does not include friction losses
or gear efficiency. The actual value would be less, and will depend on the amount of loss
within the drive system.