Z-motion robot

 

 

This section explaines how to check and adjust the Z-motion.

The gripper can be moved in Z, it uses a linear slide and a  miniature ball screw driven by a DC servo motor with integrated encoder. The Z-motion has a range from 0 to 5000. When it's initialising it drives  to the home switch and then drives 500 encoder counts out before defining the zero point.

It is important that the gripper jaws pick up the fibre at the correct place on the sharks fin. Therefore it can be necessary to check the Z-value for pick up. Further the value for the lift of the fibre is important as well because this should clear the bottom of the button from other fibres when crossed. If this value is not correctly set up it will cause fibres to catch on each other with major damage being possible.

Z-pickup value: To check this value we need to put the fibre module on. Then take off the side cover so you can look into it. It is easiest if this measurement is taken with fibre no. 121 because this sits on the X axis which makes it possible to see the sharks fin  and the gripper jaws coming over it.

On the engineering terminal:

Now move the Z axis in small steps until the gripper jaws come over the sharks fin. The jaws should cover 75% of the fin. Write down the Z value, this has to be changed in the software.

Z-lift value: This value is very important as it clears the button of the fibre so it can't pick up on any neighbouring fibres. The current value is defined  in the software.

 

Z-limit switch: Inside the gripper unit  on the back off the Z slide there's a micro switch fitted that prevents the slide to run into the hard stop if the home switch would fail. At the moment it permits a 300 micron overtravel on the homeswitch before it is operated. This switch is normally open. It is a standard microswitch.
 

 

Mechanical positions of Z motion: measured from left hand side gripper frame to body that travels up and down the linear slide.

Wake 7.13
Sleep 6.07mm
Zero set 7.13
Limit switch 7.85
mech hard out  
mech hard in 8.60

 


Distance measured from gripper frame to Z assembly. Front view right hand bottom corner with micro depthmeter. 

comments Z value 400 2000 5300
    6.77   0.15
    18.39   11.75
    18.39   11.74
      16.30 11.75
    18.37   11.73
    18.37    
belt slackened   18.23   11.59
    18.24   11.59
        11.60
         

back

Last updated 12 january 2003 by Michiel van der Hoeven