A delayed firm grip on a 2F-85 can let a heavy or long workpiece drop or rotate when the robot lifts it from the table. With rq_move_and_wait() already in use, do not add an extra wait as the first corrective action. Explicitly set the gripper force and speed to their maximum command values, then verify the grip before restoring normal machine-tending motion.
Identify the Failure Point
The reported sequence is: the gripper closes on the workpiece, the robot begins lifting, and the part remains loose until the grip becomes firm moments later. Because the same unchanged program later began dropping a previously handled part repeatedly, inspect both command settings and the physical gripping condition rather than assuming the robot path is the only variable.
| Observed condition | Engineering decision |
|---|---|
rq_move_and_wait() is already used |
Do not add a separate wait solely to obtain full force. |
| Force or speed is below maximum | Set the applicable value explicitly before commanding the grip. |
| Program is unchanged but parts now drop | Check software status and inspect the fingers, workpiece contact, and grip stability. |
Command Maximum Force and Speed
Set force and speed before the move-and-wait command so the intended values apply to the closing operation. The evidence identifies 255 as the maximum setting for both commands.
rq_set_force(255)
rq_set_speed(255)
rq_move_and_wait()This addresses low configured force or speed. It does not establish that every delayed-grip symptom is software-related; the available evidence does not identify a confirmed root cause.
Verify Before Returning to Production
- Confirm that the force and speed commands execute before
rq_move_and_wait(). - Run a controlled pickup while preventing the robot from immediately accelerating away with an unsecured part.
- Verify that the workpiece is firm in the fingers when
rq_move_and_wait()completes; do not validate the change only by observing eventual tightening. - Repeat the test with the heavy or long workpieces that previously rotated or dropped.
- Check that PolyScope and the URCap are up to date. If instability remains, inspect the fingers, contact surfaces, workpiece position, and mechanical alignment before resuming unattended operation.
A successful result is repeatable retention without slipping, rotation, or delayed tightening at lift-off. If maximum commanded force and speed do not produce that result, treat the problem as unresolved rather than compensating with an arbitrary delay.
FAQ
Do I need a wait after rq_move_and_wait() on a 2F-85?
No additional wait is indicated by the available evidence. First set force and speed explicitly, then verify that the part is secure when rq_move_and_wait() completes.
How do I set maximum 2F-85 gripper force and speed?
Call rq_set_force(255) and rq_set_speed(255) before the grip command. The value 255 is identified as the maximum for both settings.
Why does an unchanged gripper program start dropping parts?
An unchanged program does not rule out changed software status, finger contact, workpiece position, or mechanical alignment. Confirm the command values, check PolyScope and URCap update status, and retest grip stability under controlled motion.
