The tray looks fixed, but the grip looks crooked (Universal Robots UR5e)

RosaBrooks0814 · 7 Aug 2026, 05:51 UTC

Reply to discussion
RO
RosaBrooks0814
Our setup uses Universal Robots UR5e for fixture-to-tray transfer with a molded plastic sleeve in a small assembly handling cell. We've repeatedly adjusted pickup points as handling becomes unreliable. Although the tray appears unchanged, the grip no longer looks as square. I'd like an inspection sequence that helps us identify the cause before making further teaching changes or attributing it to the arm.

19 replies

JO
JoBrooks0853
Replying to RosaBrooks0814

@RosaBrooks0814 Does the angle change before contact or as the fingers close? Existing footage may help you locate where things start going wrong.

7 points
RO
RosaBrooks0814
Replying to JoBrooks0853

@JoBrooks0853 Reviewing the recording, I can see consistent seating in the checked fixture before pickup. The workpiece changes angle during gripping rather than arriving in that position.

8 points
JO
JoBrooks0853
Replying to RosaBrooks0814

Preserve the current settings and pause further nudges. Have maintenance inspect finger mounting, contact surfaces and tray seating under the proper isolation procedure, using that observation to guide the checks.

5 points
RO
RosaBrooks0814
Replying to JoBrooks0853

I've checked the maintenance history and found a pad replacement preceding the initial pickup-point correction. That establishes a relevant sequence of changes to investigate.

23 points
JO
JoBrooks0853
Replying to RosaBrooks0814

That sounds like the pad replacement caused it. Check the installation against the specified arrangement.

12 points
SA
SaraAllen0287
Replying to JoBrooks0853

Timing isn't enough to call it the cause. Check the pads, yes, but don't let one maintenance entry explain away fixture variation.

14 points
JO
JoBrooks0853
Replying to SaraAllen0287

You're right; the history supports a check, not a conclusion. Inspect the pad installation and gripping surfaces while retaining tray location in the investigation.

16 points
AA
AaronAllen0262
Replying to JoBrooks0853

My separate handling setup had both worn gripping surfaces and variation in tray seating. Coordinate corrections alone gave inconsistent results because they didn't address either underlying condition.

18 points
RO
RosaBrooks0814
Replying to AaronAllen0262

With multiple point changes already in our history, I'm unsure how to distinguish tooling and tray effects. How did you structure that comparison on your setup?

21 points
AA
AaronAllen0262
Replying to RosaBrooks0814

For my setup, a documented reference configuration anchored the investigation while maintenance assessed individual conditions. Discovering wear didn't mean we automatically restored older pickup coordinates.

9 points
LE
LeoCarter0971
Replying to AaronAllen0262

Why not just go back to the original points once the gripper's checked? Aren't those the good ones?

18 points
JO
JoBrooks0853
Replying to LeoCarter0971

@LeoCarter0971 Only if they match the verified setup. Tooling, frames or presentation may have changed; your responsible technician should compare the configuration before any supervised validation.

13 points
RO
RosaBrooks0814
Replying to JoBrooks0853

@JoBrooks0853 The relationship between the initial points and the present setup hasn't been verified. I'm retaining the current configuration instead of assuming the original positions would restore a known condition.

23 points
SA
SaraAllen0287
Replying to RosaBrooks0814

The consistent seating visible in your recording is useful, but visual familiarity doesn't establish repeatable tray location across replacements. Keep that limitation in the inspection scope.

17 points
RO
RosaBrooks0814
Replying to SaraAllen0287

Our supervised comparison has identified variation in tray seating and wear on the contact surfaces. That gives us two observed conditions to address in the investigation.

9 points
LE
LeoCarter0971
Replying to RosaBrooks0814

How would you decide whether the observed contact condition calls for cleaning or replacement? Is there a criterion beyond whether the surface looks worn?

4 points
JO
JoBrooks0853
Replying to LeoCarter0971

Use the tool maker's maintenance criteria and a qualified inspection. Appearance alone won't tell you whether cleaning restores an acceptable contact surface.

23 points
RO
RosaBrooks0814
Replying to JoBrooks0853

The observed rotation gives us an inspection plan: retain the configuration and have maintenance assess tooling and seating before further point changes or trials. I'm keeping attribution to the arm open pending that work.

7 points
JO
JoBrooks0853
Replying to RosaBrooks0814

That answers the inspection-order question. Keeping the arm diagnosis open fits what your observation actually shows.

4 points

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