Replacing robot grippers

 

 

About this topic

You can replace the robot grippers under the following circumstances:

•	One or both grippers are damaged.

•

You want to use a different set of grippers to accommodate a specific teachpoint requirement. For example, a teachpoint at a particular device might be recessed more than in other devices. So the gripper fingers must be vertically longer to reach the labware at that teachpoint. (For the list of different gripper types available, contact Automation Solutions Customer Service.)

This topic explains how to replace the robot grippers.

 

WARNING  Only administrators and experienced personnel should perform the procedures in this topic.

 

About the shim washers

Two ultra-thin washers are installed between each gripper and the robot hand, behind the screw at the back end of the gripper (1).

 

The washers are used to ensure the tips of the grippers point slightly inward to ensure optimal grip performance. The following diagram exaggerates the inward positioning.

 

Note: The number of washers used depends on the robot setup. Typically, only two washers are used behind each gripper. However, in some cases, many washers might be used to optimize grip performance.

 

CAUTION Because the washers are especially thin and light, it might be easy to lose them during the replacement procedure.

Materials and tools

Make sure you have the following:

•	Grippers you want to install

•	2.5-mm hex wrench

•	Standard caliper

Before you start

Make sure you:

1	Use DDR Diagnostics to move the robot to a position where you can easily access the robot grippers.

2	Turn off the robot and the system.

3	Disconnect the power cord from the robot power supply.

Procedure

The replacement procedure involves the following:

1	Replacing the grippers

2	Recording the gripper height

3	Recording the base clearance z-axis coordinate

Replacing the grippers

 

WARNING  Always turn off the robot and shut down the system before performing any maintenance procedure.

 

WARNING  Always disconnect the power cord from the robot power supply before performing any maintenance procedure.

To replace the robot grippers:

1	Using the 2.5-mm hex wrench, remove the two screws that are holding the gripper to the robot hand (1).

IMPORTANT As you loosen the screw at the back end of the gripper, hold a hand under the screw to catch the falling washers.

 

2	Remove the gripper.

3	Place the washers behind the new gripper, aligning them with the screw hole at the back end, and then insert a screw into the hole to hold the washers in place.

4	Position the new gripper finger at the hand as shown, and push upward so that the top of the gripper is pressed securely against the bottom of the gripper mount.

 

5	While pushing upward on the gripper:

a	Tighten the screw at the back end of the gripper.

b	Insert and tighten the remaining screw in the gripper.

6	Repeat steps 1 through 5 to replace the second gripper.

Recording the gripper height

To record the gripper height:

1	Using the caliper, measure the height of one of the grippers. Take the measurement at the middle of the gripper pad, as the following diagram shows.

 

2	In DDR Diagnostics, click the Setup tab.

3	In the Gripper Settings area, type the gripper height value you determined in step 1 in the Finger height box.

Recording the base clearance z-axis coordinate

The base clearance value is the z-axis coordinate at which the bottom of the grippers touch the top of the base. Knowing that z-coordinate prevents the robot from colliding with the base.

To record the z-axis coordinate:

1	Reconnect the power cord to the power supply and turn on the robot.

 

WARNING  Keep out of the system while the robot is starting up.

2	In DDR Diagnostics, initialize the robot profile you want to use, and then click the Jog/Move tab.

3	Using the jog commands, position the robot hand so that it is directly above the base.

 

WARNING  Keep out of the system while the robot is moving.

4	Jog the robot down along the z-axis until the bottom of the grippers touch the top of the base.

 

WARNING  Keep out of the system while the robot is moving.

 

5	In the Robot Status area, note the z-axis coordinate value.

Note: The z-axis 0 value is approximately 15 cm above the base. The z-axis value where the grippers touch the base is typically below the 0 value, so it is negative.

 

6	Click the Setup tab, and type the z-axis coordinate value in the Base clearance box.

 

 

 

Related information

 

For information about...	See...
Direct Drive Robot component names	Hardware components
Robot shutdown procedure	Turning on and turning off the robot
System shutdown procedure	System user documentation
Safety	Direct Drive Robot Site Preparation and Safety Guide
Contacting Automation Solutions Technical Support	Reporting problems