Shared workspace or guarded cell: choosing the robot class

Comparison criteria

Criteria are stated explicitly and neither option is declared a winner: which one fits depends on the constraint that binds hardest in your operation.

Collaborative describes the application, not the arm you bought

The most expensive misunderstanding in this area is treating a force-limited arm as self-certifying. Safety is assessed for the whole application: the arm, the end effector, the part being carried, the layout, and what a person is doing nearby. A blunt gripper holding a light plastic housing may need no fence. The same arm carrying a sharp-edged bracket, or a hot part, or moving above head height, can require exactly the guarding people bought it to avoid. Machinery safety standards address industrial robots and collaborative applications separately for this reason. Budget for a proper risk assessment on either route and treat any supplier who says one is unnecessary as a warning about the rest of their advice.

The arm is a minor share of what the cell costs

Both classes get quoted as a price for an arm, and that price rarely dominates the project. End-of-arm tooling designed for the specific part, the fixtures and feeders that present it in a known position, the safety devices, the electrical work, the integration with upstream equipment, the programming, and the acceptance testing typically outweigh the arm itself. This matters when comparing the classes, because a lower arm price on the collaborative side does not translate proportionally into a lower project. It also matters when the payback is calculated on the arm alone and then quietly missed. Get integrators to quote the whole cell, itemised, and compare those totals rather than the headline hardware.

Where each class actually earns its place on a floor

Force-limited arms have found their strongest ground in tasks that were never automated at all: tending a single machine, palletising modest cartons, taking a dull inspection or screwdriving job off a person in a cell that also does other work, in a plant with no robot programmers. Guarded industrial robots hold the high-volume, high-payload and precision work — body-in-white welding, foundry handling, press-to-press transfer, paint. Plenty of factories run both, chosen operation by operation. Framing the decision as old technology against new produces bad specifications in both directions: an underpowered arm struggling with a duty it was never rated for, or a fenced cell occupying floor space for a task done twice a day.

Frequently asked questions

Does a force-limited arm remove the need for a risk assessment?

It does not. The assessment covers the application as installed, including the tool, the workpiece, the reachable area and what people nearby are doing. Speed and force limiting reduces the severity of a contact; it does not address sharp edges, hot parts, trapping points between the arm and a fixture, or hazards created by the process the arm is serving. Assessment is what determines whether guarding, speed reduction, presence sensing or a redesigned tool is required, and it needs revisiting whenever the tooling or the layout changes.

Can a guarded industrial robot be operated without a fence?

Sometimes, through safety-rated functions that reduce speed or restrict the working envelope when a person is detected, verified as part of the safety design. Several manufacturers offer arms with certified safe motion functions intended for exactly this. The practical consequence is that the robot slows or stops when someone approaches, so the throughput advantage that justified the arm partly disappears while a person is present. Whether that works depends on how often people actually need to be there during production.

Which class is easier for a factory with no robotics experience?

Force-limited arms generally have a shallower entry, since teaching by hand guiding and graphical sequencing lets existing engineering staff deploy a first application without a specialist. The gap narrows once the task involves vision, complex part presentation or integration with other equipment, because those problems are the same in both classes. Either way, plan for who maintains and reprograms the cell after the integrator leaves. Applications that fall out of use usually do so because nobody in the plant could change them.