RESR angle encoder system

RESR - 3 ring Renishaw's RESR angle encoder offers impressive performance. With graduation accuracy to ±0.5 arc second and resolution to 0.01 arc second, the RESR suits the most demanding precision applications.

RESR rings

RESR - 3 ring, no heads The RESR ring is a one-piece stainless steel ring with graduations marked axially on the periphery. The 20 µm pitch RESR is compatible with the RGH20 and RGH35 readheads, while the 40 µm pitch RESR is compatible with the RGH34 and RGH40 readheads.

Graduation accuracy to ±0.5 arc second and system repeatability to 0.01 arc second
A wide range of diameters and line counts provide compatibility with industry standard controllers (Ø52 mm to Ø550 mm with line counts from 4,096 to 86,400)
Patented taper mount minimizes installation errors and simplifies integration
10 mm x 10 mm small cross section ring
Low mass, low inertia design enhances dynamic performance
One piece stainless steel ring withstands vibration, mechanical and thermal shock, and thermal overload
For even higher acceleration and deceleration, and faster settling times, extra-low inertia 'B' section rings are also available
The reference mark, which offers a repeatable home position, is provided by a separate magnetic actuator
20 µm pitch rings are compatible with the UHV compatible RGH20F readhead

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RGH20 readhead features and benefits

Compact readhead offers industry standard digital and analogue outputs
Non-contact design offers high speed, reliable operation with zero friction and zero wear
Readhead set-up LED simplifies installation
Patented filtering optics guarantee excellent signal stability in conditions unsuitable for most open, optical encoders
The RGF interface offers automatic gain control (AGC) and automatic offset control (AOC) to minimize cyclic error (<±0.1 µm)
The reference mark provides a repeatable home position whilst the limit offers end of axis travel indication
Ultra-high vacuum compatible RGH20F versions available

Compare the RGH20 with alternative optical angle readheads.

RGH35 system features and benefits

Ultra-compact component format allows integration flexibility into a range of micro systems
Non-contact format offers high speed, reliable operation with zero friction and zero wear
RGI34 interface processes signals from the RGH35 readhead into industry standard digital and analogue outputs
Low mass (<2 grams) minimizes the inertia of the system
Integral set-up LED on RGI34 interface enables easy readhead installation
Patented filtering optics guarantee excellent signal stability even in conditions considered unsuitable for open, optical encoders
For use with 20 µm pitch RESR rings

Compare the RGH35 with alternative optical angle readheads.

RGH34 readhead features and benefits

See RGH34 encoder system

RGH40 readhead features and benefits

See RGH40 encoder system

Technical specifications

Readhead dimensions	14.8 mm x 36.0 mm x 13.5 mm (RGH20) (H x L x W) 10.5 mm x 36.0 mm x 13.5 mm (RGH20F) 9.5 mm x 15.0 mm x 15.0 mm (RGH35)
Outputs (resolution)	RS422: 5 µm, 1 µm, 0.5 µm, 0.2 µm, 0.1 µm, 50 nm, 20 nm (RGH20F only), 10 nm (RGH20F only). Analogue: 1Vpp
Interpolation	RGH20 - internal interpolation to 50 nm RGH20F - RGF interface (x100 to x2000) RGH35 - RGI34 interface (x4 to x400)
Reference mark	Bolt on magnetic actuator
Limit switches	Single limit (dual limits available with RGH40 and 40 µm pitch RESR)
Maximum speed	2,938 rev/min (20 µm at Ø52 mm)
Ride height tolerance	0.8 ±0.08 mm
Scale types	20 µm pitch (compatible with RGH20 and RGH35) and 40 µm pitch (compatible with RGH34 and RGH40) RESR rings
Vacuum compatible	Yes – RGH20F and 20 µm pitch RESR

System accuracy - 20 µm pitch RESR and RGH20

Nominal outside diameter (mm)	System accuracy (arc second)
52	5.6
57	5.1
75	3.9
100	2.9
101	2.9
103	2.8
104	2.8
115	2.5
150	1.9
200	1.4

Nominal outside diameter (mm)	System accuracy (arc second)
206	1.4
209	1.4
229	1.3
255	1.1
300	1.0
350	0.8
413	0.7
417	0.7
489	0.6
550	0.5

Note: system error is graduation error plus sub-divisional error (SDE). Effects such as eccentricity influence installed performance; for application advice please contact Renishaw.

Additional resources

Accessories and external interpolation options

For further information and product options, visit the encoder product configurator.

Next steps

Contact us online if you require more information or you have a pricing query, or alternatively you may like to speak directly to your local Renishaw office.