Skip to content

Optical incremental encoder

Hengstler ICURO RI58 optical incremental encoder

Universal 58 mm incremental encoder family with up to 10,000 lines (up to 40,000 steps with edge evaluation), IP67 and many flange and connector options; hollow-shaft RI58-H takes shafts up to 12 mm and the RI58-T runs to 100 °C.

Need this part, a replacement or a complete package? Our experienced UK engineering team helps you select, source and obtain the right products, with pricing, delivery coordination and after-sales support.

Pricing and availability

Get pricing, sourcing and replacement support

Need Hengstler parts, a replacement or a suitable alternative? Send us a part number, or tell us what the machine needs to do. Our UK engineers will come back with the right product, pricing, lead time and delivery, whether that is the original part, a checked alternative or a complete axis.

  • Original parts or a checked alternative
  • Pricing, lead time and delivery in one reply
  • Components, complete axes and ongoing support

No obligation. Add what you know and an engineer will help with the rest. Prefer to configure it? Build a specification.

Add quantity, timing or application notes (optional)

Spec builder

Specify what you need instead of ICURO RI58

Select every part you need and answer the questions an applications engineer would ask. Our engineers use your specification to come back with the right products, pricing and lead times. You see your summary before we ask for any details.

Already know the part number? Send it to us directly.

  1. 1Products
  2. 2Performance
  3. 3Environment
  4. 4Volumes
  5. 5Your spec
Step 1 of 5

What are you specifying?

Select everything you need. A motor, drive and gearbox can be specified together as one axis.

1 selected: Encoder

Key specifications

Bore (max)12 mm
Ingress protectionup to IP67
Temperature (max)100 °C
Supply3–38 V wide-range option (on request)
Ppr max10,000
Counts max40,000
Temp note100 °C for the RI 58-T; RI58-H rated -10 to +70 °C
ShockRI58-H: 100 g (1,000 m/s²) for 6 ms
Housing58

Summarised in our own words from Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar)'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1 · Source 2 · Source 3

Notes on this data

RI58-H uses Hengstler's isolated opto-ASIC scanning (news page). Explosion-protected applications are referred to the RX 70-71 range.

Specify Motion is not affiliated with Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar). Hengstler and ICURO RI58 are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.

Engineer support

Speak to our engineers about your project

Our experienced engineers are on hand, ready to help with your project. Whether you need the Hengstler ICURO RI58 itself, help sourcing it, or a modified or custom design built around your load, speed and space, tell us what the machine has to do and we'll come back with the right option.

  • Help sourcing ICURO RI58 and spares for installed machines
  • Modified and custom designs when a catalogue part doesn't fit
  • Complete axis: motor, drive, gearing and feedback matched together

Typical applications

Machine tools and CNC axesPackaging machinesMotors and drivesInjection moulding machinesSawing machinesTextile machines

What an optical incremental encoder is

An optical incremental encoder measures motion by shining light through or reflecting it from a disc or scale with fine graduations onto photodetectors. As the disc or scale moves, the encoder outputs two square-wave or sine-wave channels in quadrature, called A and B, plus an index pulse once per revolution or at reference marks. The counter in the drive or controller tracks position by counting edges from a home point. Optical encoders achieve very high resolution and accuracy.

When engineers choose an optical incremental encoder

Choose an optical incremental encoder for precise speed and position feedback where homing at power-up is acceptable, such as servo motors, stages and machine tools. They are widely compatible and cost effective. The trade-offs are contamination and power loss: dust, oil and condensation can obscure the optical path, and position is lost when power is removed. For harsh environments, magnetic or inductive encoders may suit better.

How to specify the Hengstler ICURO RI58

Send these with your enquiry and an engineer can confirm the right ICURO RI58 variant or an equivalent:

  • Resolution (lines per revolution or µm)
  • Output type: TTL, HTL or sin/cos
  • Index or reference marks
  • Shaft or hollow shaft size (mm)
  • Maximum speed (rpm or m/s)
  • Supply voltage (V)
  • Environment and IP code

Common mistakes to avoid

  • Choosing resolution above what the drive input can count
  • Running long cables with TTL signals without line drivers
  • Ignoring contamination in open optical designs
  • Forgetting homing routines after power-up

Hengstler ICURO RI58: frequently asked questions

Can you help replace Hengstler ICURO RI58 or source the original?

Send the full model code, quantity and required date. Our engineers can check original-part availability and assess suitable alternatives, including supply-network options where appropriate. We confirm compatibility and any changes needed before recommending a replacement.

What is the Hengstler ICURO RI58?

Universal 58 mm incremental encoder family with up to 10,000 lines (up to 40,000 steps with edge evaluation), IP67 and many flange and connector options; hollow-shaft RI58-H takes shafts up to 12 mm and the RI58-T runs to 100 °C. Published series figures include bore 12 mm, temperature 100 °C. It is made by Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar); Specify Motion can help source it or propose an equivalent.

Who makes the Hengstler ICURO RI58?

The Hengstler ICURO RI58 is made by Hengstler (Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar)) and is listed here for engineers comparing options. Specify Motion is not affiliated with Ralliant Corporation (Hengstler GmbH, part of Hengstler-Dynapar); brand names are used only to identify the product.

What is the bore of the Hengstler ICURO RI58?

The published series maximum bore is 12 mm. Individual models and sizes in the ICURO RI58 range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.

Is there an alternative to the Hengstler ICURO RI58?

We can assess suitable replacement options. Our engineers can review the original model and propose options for your load, speed and environment. An engineer confirms the fit against your application before recommending anything.

What is quadrature output on an incremental encoder?

Quadrature output provides two channels, A and B, offset by 90 electrical degrees. Comparing which leads gives direction, and counting edges on both gives four times the line count in resolution. An index pulse marks a reference position for homing.

What is the difference between TTL and HTL outputs?

TTL outputs use a 5 V differential signal, which suits high frequencies and is commonly used with line drivers. HTL outputs use a higher voltage swing, typically matched to a 10 to 30 V supply, which improves noise immunity on long cables. Match the output type to the drive or controller input.

Further reading: Absolute vs incremental encoders · How to select an encoder · Encoders and feedback

Other optical incremental encoder series

Engineer support

Our engineers are ready to help with your project

Tell us about your project and how you use the Hengstler ICURO RI58: the load, speed, duty and environment. An experienced engineer will review it and reply, normally within one working day.

  • Reviewed by an engineer, not an autoresponder
  • Like-for-like and better-fit alternatives
  • Standard, modified and custom options

Prefer to configure it? Use the spec builder.

We use your details to answer this enquiry and share them only with the engineering and supply team handling it. Read our terms and privacy notice.

How it works

From enquiry to delivery

Send a part number or describe the application. Our engineers take it from there: the right product, a clear quotation, and delivery and support arranged.

  1. Tell us what you needSend a part number, or configure the application, quantities and timing.
  2. An engineer reviews itWe check the specification and find the original part, a checked equivalent or a complete axis.
  3. Receive your quotationProducts, pricing, lead time and compatibility notes in one reply.
  4. Order and deliveryWhen you are happy, the order is placed and delivery and after-sales support are arranged.