When you collect quotes for an end-of-line cell that stacks cartons, the figures come back far apart. The reason is rarely the robot brand. The quotes cover different scopes: one includes only the arm and gripper, another also covers the conveyor, safety equipment, software integration and commissioning.
The seven line items below make up the total cost of a palletising cell. Put your quotes side by side against this list and you can see at once what is included and what is not.
1. The robot arm: payload and reach
Two values set the price of the arm: the load it can carry and the distance it can reach. The payload calculation includes the gripper as well as the carton. Reach depends on pallet height and cell layout; for tall stacks, mounting the arm on a lift column can cost less than buying a larger arm.
2. The gripper
Cartons, sacks, bottle crates and slip sheets are not picked with the same gripper. A vacuum gripper works well on cartons with flat surfaces; porous or heavy products need a mechanical clamp. If the line runs more than one product type, the gripper has to handle all of them or be quick to change.
3. Infeed and pallet side
The conveyor that brings cartons to the robot, the stop that presents each carton at the same point, and the pallet stations are separate items. Two pallet stations let the cell switch to the second pallet when the first is full, without stopping the line.
4. Safety
Using a collaborative robot does not remove the need for safety equipment; the risk assessment covers the whole cell. Area scanners, light curtains or fencing, emergency stops and their validation should be listed explicitly in the quote.
5. Software and stacking patterns
If an operator has to call a robot programmer to define a new carton size or stacking pattern, the cell costs you money at every product change. Palletising software that lets operators enter patterns on a touchscreen settles this item from the start.
6. Connection to your systems
Where does the cell get its production order, and where does it record how many pallets it has built? Connections to ERP, manufacturing execution and traceability systems are excluded from most quotes. If you need pallet labels and lot data, this connection is essential.
7. Commissioning, training and service
Installation, on-site testing, operator and maintenance training, and support through the first period are separate items. Ask about spare parts and remote support terms at the quote stage too.
How to compare quotes
- 1.Put each quote into a table against these seven items; the empty cells are the work that is excluded.
- 2.Ask for the design rate in cartons per hour, and the carton weight it assumes, in writing.
- 3.Ask who carries out a product change and how long it takes.
- 4.Agree who is responsible for each excluded item.
The lowest quote is often the one with the narrowest scope. Compare line by line, not by the total.
To see the payback with your own figures, use the robotics module of the ROI calculator.