“Soft” Home position – Why Not?
CMT has been invited to upgrade dot-peen installations that are using a competitor’s systems and have a homing failure. We also understand that a “Soft” or programmed “Home” position” is being used in these applications.
The Red Star is at the corner of the marking window and is the actual machine home position. This position is at the end of both the X and Y axis. This position is also A hard stop position – mechanical end. In addition, at this position the pin housing is sensed with position sensors to provide a system check.
The Blue Star is the “soft” home position. This is the middle of the marking window. There is no hard backup to this position, and no electrical sensors to double check the positioning with the motion of the motors and belts.
Continuous use of a “soft” home position will ALWAYS fail eventually. CMT’s system does offer this feature – and we also provide this “soft” home feature. Our system also has a “home” check option that will return the pin housing to the actual home position every so many cycles – CMT recommends no more than 10 cycles.
CMT’s I-Mark system has larger – and more accurate motors. Also, Kevlar non-stretching belts as used to move the pin housing. These two items are at the core reason why CMT ‘s I-Mark system will provide a more reliable positioning of the “soft” home.
However…..The use of a “soft” home position is not what CMT would recommend as a solution for an industrial application.
There are two solutions:
1) Servo Motors with a ball screw drive
- This combination as used in many machining centers is the only reliable positioning for a center location of a point.
- If you really want to expand on this – please let me know
2) Z axis Approaches
- CMT offers 5 different standard solutions for the pin to approach the part and retract away from any obstructions
- These solutions are provided in the proposal – and are strongly recommended for your application.
- If you provide a drawing of the obstruction – CMT can assure and recommend which of these will provide the clearance needed.
