Unimotion Products - Renishaw Linear Encoders

Effective motion control of machines and motion systems requires a high performance rotary or linear encoder. If the application demands ultimate positioning. combined with precision and reliability, the best solution is a non-contact optical linear encoder. Renishaw's RG2 offers durable scale, excellent metrology and can be cut to any user-defined length. It also requires none of the careful handling and cleaning most traditional scales need. The unique optical arrangement maintains signal strength, purity and accuracy in conditions considered unsuitable for most open optical encoders.

The drive towards higher accuracy has made direct feedback linear encoders the preferred choice. Widespread use of linear motors for speed, positioning and simplicity has rendered the rotary encoder obsolete for many linear applications.

High speed , reliable non-contact operation suits the high speeds now found in factory automation.
Zero friction and zero mechanical wear.
Open optical systems can withstand the contamination found in most automation environments.
Flexible scale on a reel for "cut to suit" convenience (up to 70 m) and no need to stock separate lengths of scale
Patented scale applicator tool enables quick and easy installation of scale.
Integral set-up indicator lights green when corect set-up is achieved; no need for oscilloscopes or dedicated set-up equipment.
Dual limit switches offer unique end of axis travel indication.
Compact readheads with integral interpolation and a range of digital and analogue outputs from 5 µm to 10 nm
Unique thermal-matching of the scale to the substrate simplifies thermal compensation of the system.

Click here for technical info on RG2

The readhead series listed below can all be used with 20 µm RGS20-S scale. Each readhead series offers a different set of features which can be matched with specific application requirements.

Maximum flexibility, market leading performance and a low cost of ownership, have established Renishaw encoders as the designers' choice. Many years of assisting our customers with flexible tape rotary installations have taught us much about rotary applications. This experience has helped us develop a rotary encoder that incorporates more than just a list of features, but a product which fundamentally fits the applications for which it is intended.

The RESR incremental rotary encoder is based on Renishaw's unique RGR ring encoder which uses Renishaw's flexible linear scale around a stainless steel ring. The RESR however, has the scale grating (20 µm or 40 µm) marked directly onto the periphery of the ring; this eliminates the potential for signal loss at the join, simplifies set-up and enables higher speeds.

20 µm RESRs are read using Renishaw's new RGH20 readhead, whilst 40 µm RESRs are read using the RGH34 or RGH40 readheads. All readheads naturally benefit from Renishaw's unique filtering optics capable of reading over dirt, scratches or greasy fingerprints.

The RESR is available in a range of diameters, all of which feature an internal diameter some 20 mm less than the OD, giving them an ultra low section and a large internal diameter - somewhere convenient to feed all the necessary cables and pneumatic supplies. These slender dimensions also give the rings a very low moment of inertia ensuring that wherever they are installed, the system is positioned with minimal torque and maximum speed.

The slim cross section brings no compromise on accuracy; in fact combined with Renishaw's patented taper mount all installation tolerances - including those of the parent mounting surfaces - can be accomodated and run-out or ovality corrected by easy and robust fine adjustment.

Why RESR?

System accuracy of ± 0.7 arc second (on 413 mm ring)
Angular resolution to 0.1 arc second
Wide range of diameters and line counts that provide compatibility with industry standard controllers ( 52 mm to 413 mm with line counts from 4096 to 64,800 )
High speed, non-contact , optical performance
Zero backlash
Patented taper mount simplifies installation and minimises errors
UHV compatible
Low profile for easy integration
Low mass and low inertia
Ultra-low-inertia versions also available in 100, 150 and 200 mm sizes

Compatible with 20 µm RESR only
Filtering optics provide excellent dirt immunity
Compact and robust housing
Industry standard digital and analogue outputs
Integral interpolation and set-up LED
Resolutions available 5 µm, 1µm, 0.5 µm, 0.2 µm, 0.1 µm, 50 nm, 20 nm and 10 nm
Reference mark or single limit switch sensor
Hi-flex double screened 8 core cable
3-state low signal alarm output
(14.8 or 10.5) x 36.0 x 13.5 mm (HxLxW)
UHV compatible option