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:
backillum on
viewfibre 121
extended
zmove 1000 (1mm)
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.
restricted
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 | ||||
Last updated 12 january 2003 by Michiel van der Hoeven