If you have any questions regarding the guidelines laid out below or how to implement them, please contact your local Universal Robots distributor or Universal Robots sales office for further support. 

Disclaimer: This document does not replace Universal Robots standard user manual, it is intended to highlight the most critical points to new users deploying Universal Robots. This document does not guarantee completeness of all considerations for proper installation. The installation parameter values specified here are intended as starting point for an installation and should not be interpreted as specifications or limits. This article is intended to provide a set of requirements for deployment and should be complemented by further UR training. Ignoring the deployment point can lead to reduced overall lifetime of the robot system. 

NOTE: The steps and method of programming can differ depending on the SW version your robot is running, we advise to always keep to the latest Polyscope version to benefit from the latest features

A few check-list examples can be found at the bottom of this article.

1. Installation

1.1 Mounting Structure

Static mounting

The mounting surface must be rigid enough for the robot to operate precisely and repeatably and must not introduce vibration into the application. It must support:

• At least 5 times the weight of the robot arm
• At least 10 times the robot's base joint torque

Base joint torque by model:

The maximum nominal loads for worst-case movements (multiplied by a safety factor of 2.5) are listed in each robot's user manual under Dimensioning the Stand. Actual loads will not exceed these figures. Use that section to size the stand correctly.

Inverted mounting

The same requirements as static mounting apply. The mounting frame must be rigid enough to support the robot at full speed and payload. Remember to set the mounting orientation on the Installation tab.

7th-axis mounting

The same base requirements apply. In addition:

• The linear actuator must be closed-loop controlled, with full control over speed and acceleration.
• Acceleration must be kept very low so the robot itself is not affected by the axis's movement.
• If mounted on a lift kit, follow the mounting instructions in that product's spec sheet.
• If mounted on a linear slide, use set_gravity(gx, gy, gz) so external forces are represented correctly, avoiding protective stops or incorrect-mounting faults.
• If the controller detects unexpected acceleration of the robot base (linear or vertical), it may trigger a protective stop. Use set_base_acceleration(a) to tell the controller the base is moving and prevent this. The parameter a is a 3D vector describing base acceleration relative to the robot's base coordinate system.

Tool mounting

The tool output flange is where the tool is bolted to the robot. Bolts that extend too far into the flange can press against internal components and short-circuit the robot, so never exceed the maximum length for the model:

UR20 also supports an optional tool flange adapter that reduces its native ISO 9409-1-80-6-M8 pattern to ISO 9409-1-50-4-M6, for compatibility with e-Series tooling. It is limited to a 20 kg payload, and bolts must not extend more than 10 mm into the adapter. This adapter is not available for UR30.

1.2 Protection from Environment

IP rating

Robot arm IP rating by model:

IP54 means protected against limited dust ingress and splashing water; IP65 means dust-tight and protected against low-pressure water jets.

For IP54 robots, keep the robot's outer surface free of dust during routine maintenance, since small particles can still penetrate the seals. Avoid directing pressurized water at the robot, as this can force water inside and affect operation.

Corrosive fluids

The IP rating covers water and similarly non-corrosive liquids only. Cutting fluids and coolants common in CNC applications can degrade the rubber seals and reduce the robot's effective IP rating. If such fluids may contact the robot, use a protective suit.

Protective suits

Where the environment may exceed the robot's IP rating, a certified UR+ protective suit is a good countermeasure. Suits are available from several UR+ certified partners, including Roboworld, Robo-Gear, and EVOTEC (US/EU), and Shanghai Chunyu and Shenzhen Tongxing (Asia).

Electrical connection

• The control box requires 100–240 VAC, 50–60 Hz, single phase.
• Use a stable voltage line, or add a stabilizer and/or uninterruptible power supply, before connecting the robot to factory power.
• If connecting to a panel rather than the electrical grid directly, ensure it supplies 100–240 VAC and includes a fuse or circuit breaker.
• Confirm the input is single phase.
• Always ensure the ground pin of the controller socket or power panel is connected to earth.
• An external 24V power supply can feed the digital I/O terminals inside the control box; this requires removing the jumper and wiring + and − from the external supply to the control panel.

Cold environments

Where ambient temperature is close to 0°C, incorporate a warm-up routine, especially after the robot has been idle. Avoid running at high speed until the joints reach normal operating temperature — start with slow movements and increase speed gradually.

1.3 Payload Configuration

The payload mass and center of gravity (CoG) set in Polyscope must always reflect the actual payload, including the end effector. Incorrect settings can cause inaccurate or unstable movement, frequent protective stops, and reduced robot lifetime and may affect warranty coverage.

• Set the initial payload under Installation → Payload (or the TCP Setup tab on older versions). This is sufficient for applications where the payload doesn't change, such as dispensing, screwdriving, or polishing.
• For applications that pick up and put down different payloads, update the value every time the payload changes, using the script command set_payload(m, cog). On Polyscope 5.10+, the equivalent “Set Payload” command can be used instead, and additional named payloads can be configured on the Installation tab.
• The maximum allowed payload decreases as the CoG offset moves farther from the tool. Each user manual includes a graph for the specific robot model - for example, the UR20 can carry 25 kg up to a 200 mm offset, but a 400 mm offset must not exceed 16 kg.
• e-Series and newer robots include a Payload and Center of Gravity wizard (Installation → General → Payload → Measure icon) that uses the built-in force/torque sensor to estimate payload and CoG from 3–4 recorded positions. Review and adjust the resulting CoG values as needed.
• The script function estimate_payload() provides the same estimation capability from within a program, based on a list of poses and force/torque recordings.
• For long payloads or those with a large surface area, also configure the inertia matrix (Installation → General → Payload → “use custom inertia matrix”). Most CAD packages, including SolidWorks, can calculate the mass, CoG, and inertia matrix (in kg·m²) for a given end effector.
• A payload transition time (in seconds) can be set to avoid a small “jump” when the payload changes; the program continues running while the transition takes place. This is recommended when picking up or releasing heavy objects or using a vacuum gripper.
• When using multiple grippers simultaneously, configure payload and CoG for each combination carefully, since the calculations become more complex.

Tool Center Point (TCP)

The TCP is a point on the robot's tool, defined by a translation and rotation relative to the center of the tool output flange. Waypoints and linear moves are calculated relative to the TCP, not the tool flange, so an incorrectly configured TCP can cause unwanted protective stops or unexpected movement. Always configure the TCP correctly for the application.

2. Motion Programming

2.1 Blend Radii

A blend radius lets the robot pass through a waypoint without coming to a full stop, reducing cycle time and joint stress compared with decelerating, stopping, and re-accelerating. Add blends wherever the robot doesn't need to stop to perform an action — this should be the first method used to reduce cycle time, before increasing speed or acceleration.

• Use a blend radius of at least 15 mm as a general minimum.
• MoveP uses blending to hold a constant speed for process applications like dispensing; only use it when constant speed is actually required.
• Blends must not overlap. An overlap causes the waypoint to be skipped, resulting in unintended motion. Polyscope normally prevents entering overlapping values, but it can still occur in some cases - if the log shows overlapping-blend warnings (error C171), reduce the blend radius.
• Aborted or incomplete blends (for example, a blocking function immediately after a blended waypoint) can cause unnecessary hard decelerations. Very small blend radii can also make the path turn sharply and produce jerky motion.

2.2 Acceleration Values

Acceleration determines how quickly the robot reaches its target speed for a move. Set it as low as possible while still meeting cycle time requirements - optimize paths and blends first, and only increase acceleration afterward, since higher acceleration increases torque and stress on the joint gearboxes.

Recommended maximums:

• MoveJ (joint space): 800°/s²
• MoveL (linear): 2500 mm/s²

Exceeding these values may reduce joint lifetime and can affect warranty coverage.

2.3 Singularities

A singularity is a robot pose where no valid set of joint positions can move the TCP as commanded. Moving too close to one can cause a sudden increase in joint speed and trigger a protective stop. There are three main types: outer workspace, inner workspace, and wrist alignment singularities. Avoid programming waypoints near any of these.

To resolve a singularity issue:

• Change the move type from MoveL to MoveJ.
• Reposition the robot base or surrounding equipment so the path avoids the singularity zone.
• Change the tool's orientation or length to alter the joint configuration needed to reach the target TCP position.

On Polyscope 5.10+, the Move tab flags when the robot is approaching or inside a singularity and highlights the affected joint(s).

Application-specific notes:

• Palletizing wizards can auto-generate waypoints that are out of the robot's reach - always test palletizing routines before go-live.
• In force mode, the robot's position varies slightly run to run, so waypoints placed close to a singularity can become unstable if the robot drifts into it. Force mode can also lock out different axes, creating unexpected singularities. Avoid programming force-mode waypoints near singularities.

Position limits: robot motion near joint limits or safety limits (such as a safety plane) can trigger position-limit protective stops (C150, C151, C152). Set limits according to your risk assessment, with adequate margin in the program.

2.4 Protective Stops

A protective stop halts the robot program because the robot cannot follow its intended path. It exists to let the robot detect external collisions and limit the force it applies to its environment, protecting people nearby - it is not designed to protect the robot itself from routine collisions. A properly configured application should not experience protective stops during normal operation; any that do occur should be resolved during testing.

Common causes:

• Incorrect payload mass or center of gravity
• Acceleration that exceeds the joints' torque capability
• Poorly placed waypoints causing the tool to collide with a workpiece or fixture

Any application with recurring protective stops should be corrected immediately to avoid premature joint failure.

3. Maintenance & Troubleshooting

3.1 Recommended Inspection Activities

Follow the inspection plan in the UR service manual for your robot. Carrying out these checks regularly eliminates many potential failures and extends the product's life. Report any issues found to your local Universal Robots representative for prompt resolution.

3.2 Troubleshooting

Position deviation warning

position_deviation_warning(True, 0.4) logs a warning when the robot deviates from its planned path beyond a set threshold (0 = no deviation, 1 = enough deviation to trigger a protective stop). Add this line at the start of a program to catch issues before they cause a stop.

• Start with a threshold of 0.4 to gauge how well the application is tuned.
• A logged warning identifies which joint is deviating and by how much - use this to check payload/CoG settings and adjust acceleration for that move.
• In a well-tuned application, deviations should not exceed 20%.

Pause on error code

pause_on_error_code(x, y) pauses the program as soon as a specified error occurs (errors appear in the log as CxAy, where y is optional). It only takes effect during program execution and resets when the program stops. Add it to the “Before Start” sequence so it's active whenever the program runs; it can be removed once the program has been debugged. Common codes: C173/C174 (high torque) and C171 (overlapping blends).

Log Viewer

UR Log Viewer is a free tool for reading and visualizing the robot's support file, covering log messages and flight records for the robot's lifetime, with real-time recording. It helps diagnose robot behavior and identify programming or application improvements. Interpretation of the results is the user's responsibility. Visit the UR support site for installation and startup instructions.