Universal Robots Forum

Minimum move resolution in UR3e

I used UR3 in my project about two years ago. The repeatability of UR3 is 0.1mm (or 3.9 mil. inch). The minimum step I could program the UR3 to move was 0.15mm (or 5.9 mil. inch) in X or Y direction. Any number smaller than 0.15 mm, the robot just did not move at all.
A new project required higher accuracy is coming. The e-series, like UR3e, is what I am planning to use. From the spec sheet, the repeatability is 0.03 mm. One more information I can not find from the spec sheet is the step resolution. Any one know what is the minimum step the UR3e can move in X and Y direction? Thank you in advance.

UR does not spec minimum step size. It is highly dependent on your particular set up, influenced by speed, payload, acceleration, and pose. For very small moves, it’s often helpful to increase the acceleration. You will have to test your scenario to be sure… have you contacted your local distributor about a e-series demo?

Thank you for your input! I will contact the local distributor for an e-series demo.

I did some lab testing with SICK OD Mini Prime laser distance sensor, and eSeries UR3.
Minimum distance that you can program is 0.1mm. Tool doesn’t move when programmed to smaller distances.

Below you can see graph of data captured by robot when moving between 2 waypoints 0.1mm apart from each other on tool X axis.
Distance sensor is connected to analog input with sensitivity set to 1mA/0.1mm. Actual and target poses are scaled in meters.


This was captured in lab conditions with no load attached to the tool flange. I’d still advice getting demo with real life scenario.

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This is great information I am looking for. Appreciate your help!