QJR3-400S
SPECIFICATIONS · Specifications

QJR3-400S specifications

QJR3-400S industrial robot, with a load of 3kg and an armspan of 400mm.

Maximum load3kg
Maximum reach400mm
Repeatability±0.01mm
Product positioningSuitable for assembly, loading and unloading, handling, sorting, inspection, gluing, and more

QJR-S Series Small High-Speed Robots · Series technical features

3-20kg · Short reach, fast beat

Low load and fast cycle

400-1000mm short arm span, maximum repeatability of ±0.01mm (QJR3-400S).

Loading/unloading/assembly orientation

The official website categorizes applications into loading/unloading, assembly, and sorting categories.

Lightweight body

The compact machine body is suitable for machine tools and narrow workstations.

QJR-S Series Small High-Speed Robots · Other models in the same series

Compare load and reach to choose the model that best suits your process.

QJR3-400S model positioning and working condition adaptation

QJR3-400S It belongs to the QJAR Robotics QJR-S series of small high-speed robots, featuring a rated load of 3kg, a motion radius of 400mm, and a repeatability of ±0.01mm. QJAR Robotics' technical foundation is based on the background of QJAR motorcycle equipment manufacturing, with the QJR series focusing on welding and general handling both for its cost-effectiveness. The control platform is the QJAR Controller (QJR platform), and the program ecosystem consists of graphical programming + welding process packages.

From the perspective of working condition adaptation, typical applications for small load (3kg) positioning are:High-speed sorting, precision assembly, dispensing coating, and inspection/pick-and-place processing。 The short arm (400mm) model has a compact structure, suitable for dense workstations and close-range pick-and-place operations, with a small work unit footprint. ± 0.01mm repeatability is precision-grade, meeting the trajectory requirements for precision assembly, dispensing, and inspection guidance. Although the load is light, it is recommended to keep the total weight of the end and workpiece within 70% of the rated value, leaving ample acceleration margin at high speeds.

Engineering implications of QJR3-400S specification parameters
ParametersEngineering interpretation and usage recommendations
Rated load 3kgIt is recommended to reserve a load margin of 20%–30%; Verification is made by combining end self-weight + workpiece + imbalanced load inertia, especially sensitive to high-speed conditions
Movement radius: 400mmDetermine the radius of the workcell layout: bins, tooling, and fences are bounded by maximum arm span + safety distance; Verify the accessibility of each pick-and-place point during cross-station service
Repeatability: ±0.01mmRepeatability ≠ absolute accuracy: Precision assembly requires external measurement closed-loop or visual guidance; Long-term accuracy trends rely on annual retest management
Controller: QJAR Controller (QJR platform)Decide on the process ecosystem, spare parts channels, and second-hand residual value; Currently, spare parts channels are smooth, and repair and upgrade paths are mature

Control systems and common failure modes

The QJAR controller (QJR platform) compatible with the QJR3-400S features a programming language and development environment of graphical programming + welding process packages. Maintenance of this generation of control platforms focuses on three basic components: power, storage, and cooling—most "sudden downtime" can be detected in advance when preventive maintenance is in place.

QJAR Robotics Platform High-Frequency Faults and Early Warning Signals
Failure modeTypical performanceDisposal recommendations
Driver overcurrent alarmDriver overcurrent alarmIncluded as a mandatory inspection item for annual maintenance, with spare parts stocked in advance
Encoder cable interferenceEncoder cable interferenceInitial interpretation of alarm codes by reference with manuals, remote diagnosis allows for early positioning
Welding process parameter driftDrift of welding process parameters (welding machine linkage)Daily inspection coverage, with abnormal trends (abnormal noises/temperature rise/errors) recorded
Showing the wear and tear of the teaching deviceShowing the wear and tear of the teaching deviceQuarterly dust removal maintenance and cabinet temperature monitoring
QJR3-400S Maintenance Key Points List (QJAR Robotics Platform)
Maintenance projectsCycle recommendationsKey points
Batteries should be replaced periodicallyBy cycleBatteries should be replaced periodically
Welding linkage parameters should be regularly calibratedPeriodicallyWelding linkage parameters should be regularly calibrated
Reducer lubrication managementAccording to the manufacturer's manual cycleReducer lubrication management
Cable and drag chain inspectionevery six monthsInsulation, shielding, and bending radius inspection of power and encoder lines, as well as wear of cables inside the drag chain, are the main causes of intermittent faults
Zero point and accuracy retestEvery yearRepeatability measured by dial gauges or laser trackers, drift trend digitization—accuracy degradation can be seen six months in advance
Control cabinet dust removal and fansEvery quarterFilter cleaning, fan speed and noise checks, cabinet temperature recording; Dust environments shorten the cycle

Henghuan's service capabilities for the QJR3-400S

This site is a third-party robotics technology service provider. The QJR3-400S supports eight major business services as follows (ranked by service frequency of each model):

  • Maintenance and repairFor on-site diagnostics, board-level repairs, and annual maintenance contracts for the QJR3-400S—battery replacement by cycle, we follow SOPs and respond to Sichuan-Chongqing on the same day.
  • Used & in-stock robot sales: Affordable second-hand prices, budget choice for welding and handling conditions; Perform full-axis precision inspection before purchasing; The QJR3-400S or equivalent models in the inventory come with a full-function test report and a 12-month warranty.
  • Sales of new industrial robots: When adding new production lines or replacing entire batches, we conduct cross-brand selection comparisons based on process requirements (including models of the same class as QJAR Robotics), and provide configuration and pricing plans.
  • Applied technology services: Process programming, trajectory optimization, cycle tap potential, and model change formula management for the QJR3-400S, with targeted commissioning based on high-speed sorting, precision assembly, dispensing and coating, and inspection/pick-and-place conditions.
  • Research and development of automation equipment: Custom fixture ends, peripheral tooling, and safety fences for QJR3-400S, with interfaces designed according to QJAR Robotics flange and IO standards.
  • Robot rental: For short-term capacity or process validation periods, QJR3-400S equivalent in-stock models can be rented, including transportation, installation, and commissioning, with flexible rental periods and flexible purchase options.

Common issues with this device

Is it easy to find spare parts for the QJR3-400S?

QJAR Robotics: Spare parts channels for this generation are smooth; we have in-stock or short-cycle channels for standard parts such as drivers, power modules, batteries, and teach pendant components; It is recommended to configure consumables for battery replacement periodically according to the annual maintenance contract.

With a rated load of 3kg, how much weight can it actually handle?

The rated load is the static load limit of the flange surface. In actual selection, three factors must be considered: the self-weight of the end fixture (vacuum suction cup groups or grippers often account for 2–5kg), the inertia generated by the workpiece offload (checked according to the inertia ratio when the center of gravity deviates from the flange center), and the dynamic load during high-speed movement. The conventional engineering practice is to keep the "end + workpiece" within 70%–80% of the rated value to ensure cycle time and service life.

If the equipment's accuracy deteriorates after several years of use, how can it be restored?

According to the inspection order: first check whether the zero point is drifting (common after collision or battery depletion), then perform zero calibration; Check the reducer's return error (actual measurement of forward and reverse positioning deviation; if exceeded, disassemble or replace); Then check the installation base fastening and foundation settlement; Finally, trajectory compensation parameter restructuring. Most accuracy issues can be mostly restored after calibration and maintenance, so there is no need to rush into major repairs—we first release the inspection data before deciding on the plan.

Is the used QJR3-400S worth buying?

Affordable second-hand prices, budget-friendly options for welding and handling conditions; Perform full-axis precision inspection before purchasing. Three essential items for second-hand procurement: comprehensive inspection reports (axial accuracy, driver status, insulation and battery), maintenance history and operating hours, controller generation, and software license integrity. Every used machine we sell comes with inspection records and a 12-month warranty, and we can also accept third-party inspections designated by customers.

Need technical support or procurement for this model?

Whether it's model selection comparison, installation and commissioning, or maintenance of in-use equipment, you can contact Henghuan. Tell us about your processes, loads, and equipment status, and we will provide third-party technical support and solution recommendations.

Contact Henghuan Back to the full series
Service areas (by response priority): based in Nanchong, with same-day coverage of Shunqing, Gaoping and Jialing districts plus Langzhong, Yilong, Xichong, Nanbu, Yingshan and Peng'an; province-wide service across Sichuan (Chengdu, Mianyang, Deyang, Yibin, Luzhou, Zigong); on-site within 48 hours in Chongqing; scheduled visits to Kunming, Guiyang and nearby prefecture-level cities such as Qujing, Yuxi and Zunyi; remote diagnostics and mail-in repair for customers outside these regions. View full service areas →