How do you overcome issues with position values of a 2F85 being returned differently?

Josh_Westmoreland

Hey everyone, wanted to pose this question as I am currently trying to overcome this issue.  If for whatever reason the pick doesn't go perfectly, the following picks will return different position values.  The problem is that the position value is being utilized to determine part number through a logic sequence of the robot program.  If all goes well, there is no issue but if there is any disturbance it acts almost as if the gripper has lost a calibration.  The workaround being used currently is closing then opening the gripper at the beginning of each cycle.  That works well, but it increases cycle time so I am hoping there is a better solution.  I would appreciate any feedback you could offer.

Thanks!

Sebastien

@Josh_Westmoreland
We had a similar issue in the past and turns out that the activation procedure of the gripper may affect this. If you have an object in the gripper during the activation then you will get different step values that will determine your position. I believe that during activation, the gripper opens and close and use the difference between these two points to calculate the positions. So we added a activate gripper, release and then activate again in the before start program. This seemed a bit overkill but it worked in our situation. Also we changed the silicon tips to aluminum tips such that when closing during the activation we did not feel the impact of the soft material that can squeeze a bit differently each time.

Sebastien

By the way, any pros are using the gripper measurement for quality check purposes? What is the highest resolution we can get out of a measurement made using the gripper's positions? What material is the part and the tips made off in this case?

Josh_Westmoreland

Thanks Sebastien, but that isn't really the case here.  When the gripper is activated there is nothing in the fingers that could cause the issue.