4. Concepts of the cam disc
31
Festo.P.BE-CMMP-CAM-SW-EN en 1105a
4.9.4
Endless and finite cam discs
Most mechanical cam discs can be endless, i.e. cyclically run through: after one revolution,
the cam disc is at the start again and can be run through again in the same direction (or in
the opposite direction as well). Together with a module positioning, an endless cam disc
must always be used.
The displacement plan editor tries to connect the end of a curve with the beginning
(identical Y-values in the diagram):
If a cam disc in the operation should execute less than a complete revolution and then
return, it can be created as finite (acyclical): Beginning and end of the Y-path on the cam
disc are far apart; a certain marginal area cannot be run through; the cam disc might even
have a stop.
To keep the displacement plan editor from trying to connect the beginning and end to each
other,
the end points of the curve must lie precisely on the end points of the master
period
. Otherwise, the displacement plan editor would try to connect beginning and end
together, but the jumps in speed, acceleration and jerk could in practice not be run or only
with strongly reduced speed. In such situations, the displacement plan editor reports when
closing that the process shows a jerk at 0/360.
