Cobot Tool Changers and Integration Accessories

What Cobot Tool Changers and Accessories Do

A cobot tool changer lets one arm switch between two or more end-of-arm tools, such as a gripper and a vacuum cup, without a person unbolting anything by hand. In the guides we publish here, readers comparing cobot brands often skip straight past this hardware, then find out at quote time that the arm price never included it.

Hardware is one half of building a cobot cell. Programming the arm, from hand-guiding to ROS, is the other half, and The Bot Scout's guide to programming a cobot covers it.

Three categories of accessory sit between the cobot's wrist and the part it touches: the quick-change tool changer itself, the mounting-plate and flange standard that lets a tool bolt on in the first place, and the cable or dresspack that carries power, air, and signal down the arm. Get any one wrong and the other two stop mattering. For the safety review that governs the whole cell, including the tooling, see The Bot Scout's cobot guide.

Quick-Change Tool Changers: ATI, OnRobot, Zimmer, and Robotiq

ATI Industrial Automation, OnRobot, Zimmer Group, and Robotiq each sell a version of the same idea. Each uses a different mechanism and a different payload ceiling. ATI Industrial Automation's Quick-Change line spans a Standard and a Heavy Automation series, both built around the same patented fail-safe locking cam. Its QC-7 model handles up to 16 kg. Across the full product range, ATI rates its changers from 1.4 kg up to 4,000 kg, and ATI states the locking mechanism has run in industrial use for more than fifteen years without a failure.

OnRobot's Quick Changer takes the opposite design goal: smallest and lightest, rather than heaviest-rated. It weighs 200 g and carries a 20 kg payload rating. OnRobot's own launch announcement describes both its input and output flanges as fully compliant with the International Organization for Standardization (ISO) robot flange standard, so it drops onto a Universal Robots-class arm or a similar cobot without a custom adapter. A Dual Quick Changer variant lets two tools mount and switch within the same program.

Zimmer Group builds the changer into the workflow differently again. Its locking mechanism engages purely from the robot's own motion, with no separate power supply needed to trigger a change. Its HRC-03 collaborative gripper goes a step further and folds a Free-Drive button straight into the gripper body, so hand-guiding needs no trip to the pendant. Zimmer's MATCH platform, built with Schmalz, turns the changer itself into a mounting point for several interchangeable tools on one base, including electric grippers and vacuum generators.

Robotiq takes a fourth approach. Its quick-change mechanism ships built into the gripper, not as a separate bolt-on part. The RG2 carries a 2 kg payload and 110 mm stroke with its own quick changer included. The RG6 carries 6 kg and 150 mm stroke the same way. Robotiq also sells dual adapter plates that mount two of its grippers side by side on one arm, for a cell that alternates between two gripper types without a full tool change.

Mounting-Plate and Flange Standards

ISO 9409-1 defines the mechanical interface between a robot arm's wrist and the tool bolted to it. That covers the bolt-circle diameter, the centering collar, and the hole pattern, per the standard's own listing at ISO. A shared flange standard is the reason a gripper built for one cobot brand bolts onto another without a custom part.

Most cobots in the UR5 and UR10 payload class share the ISO 9409-1-50-4-M6 pattern. That is a 50 mm bolt circle with four M6 holes, named directly in the designation. Heavier cobots and larger industrial arms use a bigger flange variant. A tool sized for a lightweight cobot will not simply bolt onto a heavier one without checking the pattern first.

Non-collaborative arms that predate this common pattern still need an adapter. OnRobot's Converter Kit, launched at Automate 2019, adds a plate that converts a robot's own flange to OnRobot's standard mounting interface. OnRobot separately sells flange adapter kits scoped to specific KUKA, FANUC, ABB, Denso, and Kawasaki models, per OnRobot's own product listings. Confirm the exact flange size against the cobot's payload class before ordering a gripper. Do not confirm it against the brand name alone.

Cable Management Options

Cable management on a cobot runs two ways. An external dresspack clips onto the outside of the arm. Through-arm cabling instead runs inside the robot itself. A dresspack is a bundled cable and hose assembly that routes power, air, and signal lines along every moving joint. igus sells cobot-specific dresspacks under its triflex R line, built with a defined bend radius, a torsion stop, and a split internal cavity that keeps cable types separated, including kits sized for Techman Robot and FANUC CRX arms specifically.

External routing adds bulk to the arm's outer profile. That matters more on a cobot than on a caged industrial robot, because the profile is exactly what a person's hand or arm might contact during shared-space work. The Southwest Research Institute has researched cable-routing solutions built around that constraint for collaborative robots. Any cable bundle added to a cobot's exterior belongs in the same risk assessment as the tool itself, checked against the contact-force limits in ISO/TS 15066 for the body region the cable could reach.

Through-arm cabling avoids the external bulk problem by routing lines inside the arm's own housing, a design choice increasingly common on newer cobot generations. It costs more to service. A technician has to open the arm instead of unclipping an external dresspack. In exchange, it removes the pinch and snag points an external bundle can create in a shared workspace.

Payload and Reach by Cobot Size Class

Cobot weight classes generally break into light, mid, and heavy. The tool changer, gripper, and cabling chosen for one class rarely transfer cleanly to another. Universal Robots' current lineup spans the 3 kg UR3e up to the 30-to-35 kg UR30, per Universal Robots' own published specifications for each model. FANUC's CRX line covers a comparable range. Its CRX-10iA carries a 10 kg payload and 1,249 mm reach, per FANUC's own CRX-10iA product page, and the range extends to 30 kg on the CRX-30iA. The Bot Scout's FANUC cobot guide breaks down the full CRX and CR family. ABB's GoFa CRB 15000 family adds a third data point in the light-to-mid range, with variants from 5 kg at 950 mm reach up to 10 kg at 1,520 mm reach, per The Robot Report's coverage of the GoFa line.

Elite Robots' CS series tops out at 20 kg on the CS620. Elite Robots built it to Ingress Protection (IP) ratings of IP65 and IP68, per Elite Robots' own CS series page, which let the arm sit inside a dusty or spatter-heavy cell without a separate enclosure. That spread of numbers is the reason a payload class, not a brand name, should drive the tool-changer and gripper shortlist for any given job.

Matching a Tool Changer to Your Payload Budget

Every gram bolted onto a cobot's wrist comes out of that model's rated payload before the part being handled counts at all. Skipping this arithmetic is the most common tooling mistake on a first cobot project. A Universal Robots UR10e is rated at 12.5 kg. An OnRobot Quick Changer adds 200 g. A Robotiq 2F-85 gripper adds 925 g including its coupling, per Robotiq's own specifications, for a combined tool-side weight of about 1.1 kg.

Subtract that 1.1 kg from the UR10e's 12.5 kg rating. Roughly 11.4 kg is left for the actual part, fixture contact, and any force applied during the task. That margin shrinks further with a heavier gripper, a force-torque sensor stacked between the changer and the gripper, or a vacuum tool carrying its own line weight. Ask for the combined weight of every accessory stacked on the wrist. Do that before confirming a cobot model can handle a given part, not just its headline payload number.

Who This Guide Is Not For

This comparison is not for a shop that has not yet picked a cobot model or a task to automate. Payload class, flange size, and cable routing all follow from the arm and the job. Settle those first. Choosing tooling before either is decided means re-buying it once the real numbers are known. Start with the base cobot guide and a specific part in hand before shortlisting a tool changer.

It also is not the deciding factor for a shop already standardized on one integrator's full cell package. There, the tool changer, cabling, and gripper typically arrive as one quoted line rather than separate purchases. That buyer's real decision is the integrator relationship, not the individual accessory brand.

What Would Change This Answer

This comparison would change if one vendor's quick changer became the de facto standard bundled with most cobot arms at purchase, the way the ISO 9409-1-50-4-M6 flange already is for lightweight cobots. No brand holds that position today. Shopping the four covered here on payload rating and mechanism still makes sense.

It would also change if through-arm cabling became standard across every cobot weight class, not just the newer, lighter models. That has not happened yet. A heavier cobot cell should still budget for an external dresspack and the service access it needs.