Buying a Used Robot: What to Ask About Its Storage History

A used robot that has been stored for a long time may look clean while important information about its storage conditions is missing. Buyers should ask where it was kept, how long it was out of service and what records exist for the arm, controller and spare parts. Storage history does not by itself prove the machine's condition, but it helps a qualified service provider plan an appropriate inspection.

Build a timeline for the actual equipment

Record the robot and controller identifiers, the date the equipment was last used, the dates it entered and left storage, and any changes of warehouse or owner. Ask whether the arm, controller, pendant and spare parts were stored together. If the seller acquired the machine after it had already been stored, distinguish the seller's direct records from information supplied by a previous owner.

Gaps in the timeline should be marked as unknown. A seller's statement that a robot was rarely used is not the same as a documented storage and maintenance history. A dated inventory and photographs can help identify what was present, but they do not establish internal condition or future reliability.

If a warehouse monitored its environment, ask for records covering the period when the robot was actually present and identify where the sensor was located. A single reading taken on the day of sale cannot describe months of conditions. Note any known interruptions, relocation or changes to packaging, and keep the seller's explanation with the equipment identifier.

Ask for the manufacturer's storage guidance

Universal Robots' long-term storage guidance describes recommendations for its robots and spare parts and treats six months or more as long-term storage in that guidance. It lists environmental conditions and discusses periodic attention to stored equipment. Those recommendations are manufacturer-specific and should not be applied to another brand or model without checking its instructions.

Request the manual for the actual equipment and its revision. Compare the stated storage requirements with the available warehouse records. If there are no temperature or humidity records, do not claim that the machine was stored within a specified range. Ask a qualified technician what inspection is appropriate before the equipment is returned to service.

Separate storage conditions from operating conditions

Storage and operation may have different temperature, humidity and installation requirements. A robot that was stored in a permitted environment still needs to be evaluated for the location where it will operate. The controller, cables, tooling and other components may have their own limits. Record the applicable document and the component to which each condition applies.

Where equipment has moved between environments, follow the manufacturer's instructions and site procedures before powering it. Do not assume that a brief visual inspection rules out moisture, damage or deterioration. The service team should decide whether additional checks or a waiting period are required for the specific equipment.

Review records of maintenance and configuration

Ask whether the robot was inspected or serviced while in storage, whether any components were replaced and whether the controller's configuration was preserved. The manufacturer guidance discusses items such as batteries and stored data; their condition and service requirements depend on the specific robot. A machine that powers on does not automatically establish that its programs, calibration or safety configuration are suitable for the buyer's application.

Do not start an unfamiliar robot or run a movement program merely to make a sale demonstration. Any functional test should be planned by qualified personnel with the correct equipment, safeguards and manufacturer's instructions. Record the conditions and limits of the demonstration and keep it separate from installation acceptance.

Plan the move from storage

Packaging and handling are separate questions from warehouse conditions. The UR3e transportation instructions discuss original packaging and warn that improper lifting can cause injury. This is an example for a specified model; use the actual manufacturer's instructions and qualified handling personnel for the equipment being sold.

Agree who supplies suitable packaging, who prepares the machine and who records its condition before dispatch and after receipt. If the original packaging is unavailable, ask the manufacturer or service provider about the appropriate handling requirements and any effect on warranty. Do not infer that an improvised crate offers equivalent protection.

Make the uncertainty visible in the sale

Attach the storage timeline, available inspection records, disclosed damage and unresolved questions to the equipment listing or purchase file. Agree whether a service inspection is required before acceptance and who pays for any needed repair. Avoid describing a robot as fully serviced or ready for production unless the evidence supports that precise claim.

For another aspect of a used equipment handover, see our spare-parts identification guide and browse the robot trading archive. A clear storage record helps both parties understand what is known and what still needs to be checked.