What a robot eats: power, compressed air, sandpaper and software
A robot has no salary, which is the whole pitch, and it has an appetite, which is the part of the pitch nobody finishes. Here is what a working cell consumes in a year, line by line, so the operating cost shows up in your arithmetic before it shows up on your invoices.
The short answer
A collaborative arm draws less power than a space heater and an industrial arm somewhat more; electricity is rarely the line that matters. What matters is everything downstream of the wrist: compressed air for grippers and tools, process consumables like abrasive, welding wire and gas, the software plan on machines that run one, and the service contract. A sanding robot eats sandpaper at a steady, aggressive rate because it never gets tired and eases off. A scrubber comes with an annual software plan whether anyone mentioned it or not. Feed them on paper first.
Electricity
Modest. A cobot at work might draw a few hundred watts; a large industrial arm, a few kilowatts under load. Over a year of two shifts that is a utility line you will notice but not fear. The machine the robot tends, the dust collector and the compressor usually eat more.
Compressed air
Pneumatic grippers, vacuum generators, blow-offs and door actuators run on plant air, and plant air is one of the most expensive utilities in a factory per unit of work. A vacuum gripper on a palletizer or a blow-off that runs every cycle can be a real line. Electric grippers and electric vacuum pumps are the quiet alternative. Ask the integrator for the cell's air consumption, and ask whether your compressor has the headroom, because a cell that starves the paint line of air has made an enemy.
Process consumables
This is where the appetite lives. Abrasive on a sanding or deburring cell, which the worked example on this site raises by 30 percent over the manual baseline because the robot does not ease off, though the published accounts in the casebook include shops reporting abrasive savings from more consistent pressure, so measure yours. Welding wire, gas and contact tips, consumed at the robot's steadier duty cycle. Suction cups, which are a consumable, not a part. Labels, film, glue. Whatever the process used before, the robot will use at least as steadily.
Software plans and subscriptions
Some robots are sold outright and run for a decade on their original software. Others, notably autonomous floor scrubbers and some mobile robot fleets, run on a plan: mapping, routing, the dashboard, updates, and in some cases the right to operate at all. Every scrubber in the matrix runs on one. The honest total is machine plus plan plus service, and the concierge says so every time, because the plan is the line brochures put in the footnote.
Service, parts and the shelf
A spare parts kit at commissioning, a yearly service visit, and the unscheduled calls. On a simple cell this is a small number that becomes a large one the first time a proprietary cable fails and nobody stocked it. Budget the kit on day one.
People
The cell does not remove people from the plant. It moves them. Someone loads the table of blanks, clears the jam, checks the first part in the morning and orders the suction cups. In the worked examples on this site this shows up as a fraction of a position kept, three quarters freed rather than a whole, and it is the single most common thing a payback calculation forgets.
How to put it on one page
Ask the integrator for a one year operating estimate with these lines on it: electricity, air, process consumables, software, service and parts, and the human hours kept. Then put that total under the equipment and integration ranges, which the application guides on this site publish side by side, and you have the fraction that tells the truth. The replicator on the Enterprise made tea from nothing. Nothing on your floor does.
Tell Joe, the concierge on this site, what process you are automating and he will tell you which of these lines is the hungry one for your cell. For sanding it is the abrasive. For scrubbers it is the plan. For palletizing it is almost nothing, which is one reason palletizers pay back fast.
Related on this site
- Three ways a payback calculation lies to you
- I never thought we could afford a sanding robot. The dust and the overtime said otherwise
- I never thought we could afford a floor scrubbing robot. The honest math said: only if it runs more
- Robots don't take breaks, but they do take vacations
- Sanding and finishing
The arm itself is cheap to feed. The gripper's air, the process consumables, the software plan and the service contract are the real diet. Put them on the same page as the purchase price.
Put it to the test on your own job
Tell Joe what you are running and he will apply this to your numbers, including telling you when a robot is the wrong answer.
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