RS4-551S SCARA Robotic Arm (Manipulator)
SCARA Robot · Load 4 kg · Arm length 550 mm
RS4-551S specifications
The creation of RS4 robots aims to provide high-performance robots with greater workspace efficiency. The RS4 is a SCARA+ with a 550 mm arm length, capable of working on pallets measuring 777 mm x 777 mm, while the typical SCARA arm length is nearly 1000 mm. Additionally, since the RS-series arm can move in the center of the work area, the movement distance is shorter, eliminating the need to always circle around the center of the workspace like other SCAR robots, which greatly shortens cycle time. These advantages, combined with our industry-leading ease of use and powerful controllers, have made the RS series robots quickly favored by customers.
Model introduction
The creation of RS4 robots aims to provide high-performance robots with greater workspace efficiency. The RS4 is a SCARA+ with a 550 mm arm length, capable of working on pallets measuring 777 mm x 777 mm, while the typical SCARA arm length is nearly 1000 mm. Additionally, since the RS-series arm can move in the center of the work area, the movement distance is shorter, eliminating the need to always circle around the center of the workspace like other SCAR robots, which greatly shortens cycle time. These advantages, combined with our industry-leading ease of use and powerful controllers, have made the RS series robots quickly favored by customers. High performance: high workspace utilization (no dead corners); 0.39-second cycle time can increase the total throughput of components; Excellent acceleration/deceleration rates and smooth start/stop times; The unique "cross-center" movement shortens cycle time; Power Drive servo technology delivers powerful dynamic performance. Unique design improves workspace utilization: hanger installation eliminates dead corners; The perfect cylindrical space can be extended to a larger area; The first and second joints can move +/- 225 mm; The second joint can be fully moved beneath the first joint, achieving high space efficiency. Powerful controllers and development software: the Epson RC+ development environment offers industry-leading ease of use (saving development time); The dual-layer controller enables high-performance or low-cost RS3 robot solutions; High-performance processing power is many times faster than competitors' products; Integrated options can significantly improve system performance and shorten overall development time (see the options page for more details).
RS4-551S exclusive highlights
High workspace utilization (no dead corners); 0.39-second cycle time can increase the total throughput of components; Excellent acceleration/deceleration rates and smooth start/stop times; The unique "cross-center" movement shortens cycle time; Power Drive servo technology delivers powerful sporting performance
Hanger installation eliminates dead corners; The perfect cylindrical space can be extended to a larger area; The first and second joints can move +/- 225 mm; The second joint can be fully moved beneath the first joint, achieving greater spatial efficiency
The Epson RC+ development environment offers industry-leading ease of use (saving development time); The dual-layer controller enables high-performance or low-cost RS3 robot solutions; High-performance processing power is many times faster than competitors' products; Integrated options can significantly improve system performance and shorten overall development time (see the options page for more details).
The Vision Guide Vision Guidance solution offers industry-leading ease of use; Microsoft. .NET supports RC180 and RC620+ (discontinued) controllers (using programs such as VB, C/C++, LabVIEW, etc.); Integrated communication modules, including: Profibus, DeviceNet, CC-Link, and Ethernet/IP (only RC620+ (discontinued)); GUI Builder allows easy creation of operator interfaces from Epson RC+ development environments; Provides integrated Conveyor Tracking, Additional I/O, Force Sensing, and many highly integrated features
Automobiles; Consumer products; Industrial products; Telecommunications; Pharmaceuticals; Packaging
RS Series SCARA · Lifting Specialized · Series technical features
The RS series is a SCARA robot installed in a suspended (upside-down) setting, entering the work area from above, suitable for pick-and-place and assembly scenarios where there are obstacles below the workpiece and you need to avoid it.
Inverted installation frees up desk space, facilitating conveyor lines and multi-station layout.
RS3/RS4/RS6 cover the needs for light and medium-sized pick-up, place, and assembly.
Sharing the RC+ programming environment with a vision and I/O option ecosystem.
Typical application scenarios
Common application processes for this model (click to view process details):
RS Series SCARA · Lifting Specialized · Other models in the same series
Compare load and reach to choose the model that best suits your process.
RS4-551S model positioning and working condition adaptation
RS4-551S Belongs to the Epson RS series SCARA · The SCARA horizontal multi-joint robot model is dedicated to lifting, with a rated load of 4kg, a motion radius of 550mm, and a repeatability of ±0.015mm. Epson's technological foundation is SCARA's global market leader: RS/GX/LS series with high speed and precision, SPEL+ development efficiency, and mature vision integration; The control platform is RC700-A, and the program ecosystem is SPEL+ language (BASIC style) + Vision Guide visual.
From the perspective of working condition adaptation, typical applications for small load (4kg) positioning are:High-speed sorting, precision assembly, dispensing coating, and inspection/pick-and-place processingCommon application processes for this model include handling, assembly, and inspection. The short-span (550mm) model has a compact structure, suitable for dense workstations and close-range pick-and-place operations, with a small working unit footprint. ± 0.015mm repeatability is the standard level for six-axis industrial robots, covering most working conditions such as welding, handling, palletizing, and loading/unloading. 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.
| Parameters | Engineering interpretation and usage recommendations |
|---|---|
| Rated load 4kg | It 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 |
| Radius of motion: 550mm | Determine 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: ±0.015mm | Repeatability ≠ absolute accuracy: Precision assembly requires external measurement closed-loop or visual guidance; Long-term accuracy trends rely on annual retest management |
| Main unit weight: 19kg | Installation base and foundation load-bearing check based on weight + dynamic load; Floor slab installation requires structural calculation, with heavy-duty models serving as independent foundations |
| Controller RC700-A | 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 RS4-551S is paired with the RC700-A controller, with a programming language and development environment of SPEL+ (BASIC style) + Vision Guide for visual use. 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.
| Failure mode | Typical performance | Disposal recommendations |
|---|---|---|
| SCARA synchronous belt tension attenuation and wear | SCARA Synchronous Belt Tension Attenuation and Wear (Main Cause of Precision Drift) | Included as a mandatory inspection item for annual maintenance, with spare parts stocked in advance |
| The encoder battery is depleted | Encoder battery depleted (loss of origin and calibration data) | Initial interpretation of alarm codes by reference with manuals, remote diagnosis allows for early positioning |
| Driver alarm | Driver alarm (high-speed overcurrent) | Daily inspection coverage, with abnormal trends (abnormal noises/temperature rise/errors) recorded |
| RC controller fan and power supply aging | RC controller fan and power supply aging | Quarterly dust removal maintenance and cabinet temperature monitoring |
| Maintenance projects | Cycle recommendations | Key points |
|---|---|---|
| Timing belt tension adjusted by periodic inspection (SCARA specific item) | By cycle | Timing belt tension adjusted by periodic inspection (SCARA specific item) |
| Annual battery replacement | Year | Battery replacement annually, calibration data backup |
| Guide rails and screw lubrication (LS/GX series) | According to the manufacturer's manual cycle | Guide rails and screw lubrication (LS/GX series) |
| Cable and drag chain inspection | every six months | Insulation, 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 retest | Every year | Repeatability measured by dial gauges or laser trackers, drift trend digitization—accuracy degradation can be seen six months in advance |
| Control cabinet dust removal and fans | Every quarter | Filter cleaning, fan speed and noise checks, cabinet temperature recording; Dust environments shorten the cycle |
Henghuan's service capabilities for RS4-551S
This site is a third-party robotics technology service provider. The eight major services related to RS4-551S are supported as follows (sorted by service frequency of each model):
- Maintenance and repair: For on-site diagnostics, board-level maintenance, and annual maintenance contracts for RS4-551S—periodic inspection and adjustment of synchronous belt tension (SCARA special item), we follow SOPs and respond to Sichuan-Chongqing on the same day.
- Used & in-stock robot sales: SCARA has a large second-hand circulation and is the preferred choice for 3C and electronic assembly conditions; Procurement focuses on inspecting belt and guide rail wear; The RS4-551S or equivalent models in stock 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 grade as Epson), and provide configuration and pricing plans.
- Applied technology services: Process programming, trajectory optimization, tap time potential, and formula management for RS4-551S, with targeted commissioning according to handling, assembly, and inspection conditions.
- Research and development of automation equipment: Custom fixture ends, peripheral tooling, and safety fences for RS4-551S, with interfaces designed according to Epson flange and IO standards.
- Robot rental: For short-term capacity or process validation periods, RS4-551S equivalent in-stock models can be rented, including transportation, installation, and commissioning; rental terms are flexible and can be repurchased.
Common issues with this device
Is it easy to find spare parts for RS4-551S?
Epson: The spare parts channel for this generation is 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 allocate consumables for periodic inspection and adjustment of synchronous belt tension (SCARA specific items) according to the annual maintenance contract.
With a nominal load of 4kg, how much 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 RS4-551S worth buying?
SCARA has a large second-hand circulation and is the preferred choice for 3C and electronic assembly applications; Procurement focuses on checking for belt and guide rail wear. 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.
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