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Rotation Stage with Resonant Piezoelectric Motors

  • Ø50 mm Rotation Stage with Closed-Loop Positioning
  • Open Frame Design for OEM Applications
  • Control via Interface Board, GUI, or ASCII Message Calls
  • Fully Integrated Drive Electronics

Application Idea

Rotate the diffraction grating to select the wavelengths passing through the slit.


Rotation Stage Bundle

8-32 Tapped Holes 
(M4 for ELL18K/M)
37 Places

Interface Board

Rotation Stage
(Also Available Individually)

Related Items

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Key Specificationsa
Travel (No Limit Switches)b 360° Continuous
Homing Repeatability 4.36 mrad (0.25°)
Bidirectional Repeatability 873 µrad (0.05°)
Velocity (Maximum) 430 °/s
Maximum Total Load 200 g (7.05 oz)c
DC Voltage Input 4.5 to 5.5 V
Weight of Stage and Brackets 90 g (3.17 oz)
Minimum Lifetime 100 km (600 600 Revolutions)
Stage Dimensions
(Without Brackets)
81.0 mm x 60.0 mm x 20.3 mm
(3.19" x 2.36" x 0.80")
  • See the Specs tab for complete specifications.
  • Not Intended for Continuous Operation
  • Maximum Load Must Be Centered on Stage
Elliptec OEM PageThorlabs' Elliptec Technology for OEM
The Connected Components of the ELL8K Rotation Stage Bundle
Click to Enlarge

The components of the ELL18K Rotation Stage bundle are shown connected and with key features labeled.


  • Ideal for OEMs and Applications Requiring Rapid and Precise Positioning
  • Micro-B USB and Picoflex®* Connectors for Control Signals
  • Multi-Drop Serial Communication Protocol Supported
  • Ø50.0 mm (Ø1.97") Rotation Stage
  • Absolute Home Position Found with Infrared and Magnetic Sensor Technologies
  • Magnetic Encoder Used to Position Stage

Driven by Thorlabs' Elliptec™ piezoelectric resonant motor technology, this rotation stage is designed to be a compact solution for applications requiring rotational control. Thorlabs offers the ELL18K(/M) rotation stage bundle, which contains the ELL18(/M) rotary stage, an interface board for manual control of the stage, mounting brackets, power supply, and cables for connecting the stage and interface board to each other and to a PC. The ELL18(/M) can also be purchased separately. 

Each stage has 37 8-32 (M4) tapped holes on 0.25" (6.4 mm) centers providing flexible mounting options. The rotation stage is lightweight and compact, and the closed-loop operation provides rotation to specified orientations with a repeatability of 873 µrad. The assembled components of the ELL18K(/M) ar shown in the image to the right, with key features labeled. Please see The Elliptec™ Motor tab for more information.

The motor is highly dynamic and has no gearing. The tips of both motor housings are in firm contact with the plastic track at the base of stage, as can be seen in the image at the right. The motors are installed with opposite orientations and translation in both directions occurs when one motor pushes the track forward while the other pulls it backward. The rotation stage is not designed for continuous operation. We recommend operation with duty cycles of 40% or less. When power is not applied to the motors, the stage is held in place by an approximately 0.025 N·m combined torque exerted by the stationary arms of the motors. 

The open frame format, versatility, and simplicity of this rotation stage makes it attractive for OEM applications, as it can be customized according to customer requirements and produced in high-volume quantities. Please contact us to discuss your specific requirements so that we may tailor a solution to meet the needs of your application.

There are multiple options for powering, driving, and controlling this rotation stage, which are detailed in the Positioning the Rotation Stage section of the Operation tab. The stage possesses a 3.3 V serial bus and is designed to be operated with or without the interface board; the Pin Diagram tab provides pin assignments. Thorlabs offers software for our Elliptec products capable of providing full and independent control of the stage. When the interface board is used as an accessory to change the position of the stage, its status in the software is automatically updated.

Elliptec Resonant Motor Products
Dual Position Slider ELL17 Linear Stage ELL20 Linear Stage ELL18 Rotation Stage
Multi-Position Sliders 28 mm Linear Stage 60 mm Linear Stage Rotation Stage

The multi-drop communications bus on the interface board offers the option of connecting the stage to a hybrid network of up to 16 Elliptec resonant motor products using a custom cable and controlling the connected units with a device such as a microprocessor. When multiple units are connected to the same interface board, all the units react simultaneously to comands from the buttons on the interface board while software commands can be sent to control individual stages. Please see the manual for details.

*Picoflex is a registered trademark of Molex Incorportated.

Travel 360° Continuousb
Maximum Speedc 430 °/s
Bidirectional Repeatabilityd 873 µrad (0.05°)
Homing Repeatabilityd 4.36 mrad (0.25°)
Bidirectional Accuracye 6.98 mrad (0.4°)
Backlash 226.9 µrad (0.013°)
Encoder Resolution (Relative Magnetic Encoder) 143360 counts/rev
(470.3 µrad/count)
Minimum Incremental Motion 34.9 µrad (0.002°)
Minimum Holding Torque (Both Motors Engaged) 0.015 N•m
Axis Wobblef 331.6 µrad (0.019°)
Maximum Total Loadg 0.200 kg (0.441 lbs)
Minimum Lifetimeh 600 600 Revolutionsi (100 km)
Motor Type Elliptec Resonant Piezo
DC Voltage Input 4.5 to 5.5 V
Typical Current Consumption, During Movement 800 mA
Typical Current Consumption, During Standby 50 mA
Bus Multi-Drop 3.3 V/5 V TTL RS232
Connector on Rotation Stage Board Picoflex®
Connectors on Interface Board Picoflex®, Micro USB, Power Supply
Speed 9600 baud
Data Length (1 Stop Bit, No Parity) 8 bit
Protocol Data Format ASCII HEX
Module Address and Command Format Mnemonic Character
Mounting Threads (On Stage, 37 Places) 8-32 (M4 x 0.7)
Length: 0.24" (6.0 mm) 
Dimensions of the Rotation Stage Board
(Without Mounting Brackets)
81.0 mm x 60.0 mm x 20.3 mm
(3.19" x 2.36" x 0.80")
Weight of Rotation Stage Board  90 g (3.17 oz)
Environmental Operating Conditions
Temperature Range 15 to 40 °C (59 to 104 °F)
Maximum Relative Humidity (Non-Condensing) <80% at 31 °C
Maximum Altitude 2000 m
  • Performance specifications are given for the case when the rotation stage is mounted as recommended in the Operation tab. All values were measured with a load of 64 g and a moment of inertia of 6600 g·mm2.
  • We recommend a duty cycle of 15 s running followed by 20 s cooling down. A shorter running time requires a shorter cool down time.
  • Some natrual variability in the maximum speed may be experienced. Max speed will increase with usage.
  • Maximum Difference Between Clockwise and Counterclockwise Movement to the Same Position
  • Maximum Deviation from True
  • Maximum Deviation from the Center of Rotation
  • The maximum load must be centered on the stage.
  • The rotation stage is not designed for continuous operation.
  • The number of revolutions is computed using a diameter of 53 mm, which includes the thickness of the track.
Components of the ELL18K Bundle
Click to Enlarge

Components of the ELL18K(/M) Bundle
(One Region-Specific Power Adapter Included with the Power Supply)

As shown in the image above, two mounting brackets are included with the bundle. The brackets fastens to the underside of the rotation stage's PCB with the four included screws. Each bracket features a slot for 1/4"-20 (M6) cap screws to secure the stage board to optical tables and breadboards. The bracket adds 0.05" (1.2 mm) of thickness to the profile of the stage.

The drawing below shows the dimensions and mounting features of the stage itself. The spacing and threading of the 37 mounting holes in the stage differs between the imperial (ELL18) and metric (ELL18/M) versions of the stage. All other dimensions, including the 1.97" (50.0 mm) diameter of the stage are the same for both.

Mechanical Drawings of the Dual-Position Slider
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Mechanical Drawing of the Rotation Stage
Mechanical Drawings of the Remote Handset
Click to Enlarge

Mechanical Drawing of the Interface Board
Connector J1 Pinouta
Pin Type Function
1 PWR Ground
2 OUT OTDX - Open Drain Transmit 3.3 V TTL RS232 
3 IN RX Receive - 3.3 V TTL RS232
4 OUT In Motion, Open Drain Active Low Max 5 mA
5 IN JOG/Mode, Active Low Max 5 V
6 IN BW Backward, Active Low Max 5 V
7 IN FW Forward, Active Low Max 5 V
8 PWR VCC +5 V ±10%; 800 mA
  • Connector Model Number MOLEX 90814-0808;
    Mating Connector Model Number MOLEX 90327-0308
Pinout Diagram of the Picoflex Connector on the Rotation Stage PCB
Click to Enlarge

Pinout diagram of the Picoflex connector is shown referended to a cut-away diagram
of the ELL18(/M) Rotation Stage Board.

Operation Notes

This tab contains information on handling, mounting, and operating the ELL18K(/M) Rotation Stage Bundle.



The Rotation Stage without Brackets
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The Rotation Stage
Features of the Rotation Stage
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Features of the Rotation Stage


The rotation stage and interface board included in the ELL18K(/M) bundle are robust to general handling. To ensure reliable operation, keep the surface of the plastic track contacted by the motors free of oils, dirt, and dust. It is not necessary to wear gloves while handling the rotation stage, but avoid touching the track to keep it free of oils from fingerprints. If it is necessary to clean the track, it may be wiped with isopropyl alcohol or mineral spirits (white spirit). Do not use acetone, as this solvent will damage the plastic track.

The open frame format of the ELL18(/M) can tolerate up to 8 kV of static discharge. ESD precautions should be taken, as an electrostatic discharge can produce an electrical signal that may cause an unintended movement of the stage. A bending load in excess of 500 g applied to the board may cause the PCB to deform, which will degrade the performance of the rotation stage. As readings from a magnetic sensor are used during the homing and positioning of the stage, avoid subjecting the structural PCB to excessive loads or magnetic fields. Limit the strength of magnetic fields in proximity to the magnetic sensor to ±5 mT to avoid negatively affecting the homing and positioning operations.

Mounting and Loading the Rotation Stage

The rotation stage should be mounted so that the top surface of the stage is in the horizontal plane. There are four Ø4.2 mm (Ø0.17") through holes located along the edges of the board, which are visible in the image at the center-right of this tab, that may be used to mount the stage. The ELL18K(/M) comes with two mounting brackets with slots for 1/2" (M6) screws. When mounting the stage, ensure that the installation does not bend the PCB.

Loads may be mounted to the stage using the 37 tapped holes for M4 threaded screws, whose spacing is shown in the diagram below and in the diagrams included in the Specs tab. The maximum allowed weight of the mounted components is 200 g. The mounted load must be centered on the stage in order to acheive 200 g. In all cases of mounting and loading, ensure that nothing interferes with the moving parts of the rotation stage.

Supplying Power

When the setup includes the interface board, power may be supplied through the Micro-B USB connector and/or the 5 VDC power socket located on the board. The electronics on the interface board convert the applied DC signal to a sinusoidal signal oscillating at the required resonance frequency.

The ELL18K(/M) bundle includes a 5 VDC power supply whose connector mates with the power socket on the interface board. Delivering power through this socket also allows the Micro-B USB connector to be used for a computer to control the stage remotely. The power supplied by a computer through the USB 2.0 connection is not sufficient to power the stage. If computer control is not necessary, another option for supplying power to the stage is a portable USB 5 V battery pack connected to the Micro-B USB connector on the interface board.

When the implementation does not include the interface board, the connection with the power source is made using the pins on the Picoflex connector that is included on the linear stage board. A pinout diagram of this connector is included in the Pin Diagram tab, and information on powering and addressing the rotation stage is given in the manual and the communications protocol manual, respectively.

Operation of the Motors

The motion of the rotation stage is controlled by forcing the piezoelectric elements to vibrate at specific ultrasonic frequencies. For each motor, there is one ultrasonic resonant frequency that will push the stage forward, and another that will pull the stage backward. Operating a motor at one of its resonance frequencies causes the tip of the motor to continuously cycle in a tight clockwise elliptical path. When the motor is driven at its other resonant frequency, the tip of the motor cycles through that same path in a counterclockwise direction. Both resonant frequencies are around 100 kHz. The total displacement at the tip of motor is a function of the mechanical load it is driving and the voltage supplied to the piezo element. In the case of no loading and a 5 V maximum driving voltage at a resonant frequency, the tip of the motor expands and contracts no more than a few microns while tracing the elliptical path. Please see The Elliptec™ Motor tab for more information and an animation illustrating the operational principle of the motors.

Homing the Rotation Stage

The Interface Board
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The Interface Board
The Interface Board
Click to Enlarge

Features of the Interface Board

To Home the stage, press the BW button on the interface board, click the Home button in the Elliptec software's graphical user interface (GUI) or send the appropriate ASCII message as is specified in the communications protocol manual.

The default Home position is referenced to a fixed feature on the stage assembly. If desired, the user may redefine the position of Home to be offset from the default position by up to +90° (a quarter turn in the clockwise direction). Being able to customize the Home position can be useful when synchronizing the orientations of two or more stages. When executing the Home command, the stage first finds the approximate location of Home, and then a fine-positioning procedure is used to orient the stage at Home with an accuracy of 288.0 µrad. The user can specify whether the stage rotates in a clockwise or counterclockwise direction (as defined from the perspective of looking down on the surface of the stage) during the first phase of the homing procedure, but the fine-positioning phase is always performed in the counterclockwise direction for repeatability.

Positioning the Rotation Stage

Note that the rotation stage is not intended for continuous operation. We recommend operation with duty cycles of less than 40% during general use, while operation with duty cycles greater than 60% should be limited to a few seconds.

Before the stage may be positioned, the Home position of the stage must be found. Please see the previous section for details. The movement of the stage may be controlled through computer control via the Elliptec™ software package that may be downloaded, or by sending simple signals to digital lines on the stage's board. A link to download the software and accompanying documentation can be found in the Software tab. It is also possible to effect the simultaneous movement of several rotation stages by connecting all to the communications bus. When this is done, the software can send separate commands to each stage, while commands originating from buttons pressed on the handset will be sent to all connected stages. The communications protocol manual describes how to use the software to individually address each connected stage.

The default increment to move the stage forward and backward is 45°, and a custom increment can be set using the Elliptec software or by sending the appropriate ASCII message(s) as specified in the communications protocol manual. The Elliptec software can be used to move the stage to absolute and relative positions, in addition to jogging the stage forward or backward. The software is also used to set the jog step size, read the position of the stage, and adjust the position of Home, as is described in the previous section.

Readings from the magnetic sensor, which can resolve angular increments of 24.0 µrad, are used to position the stage and when executing the Home command. The travel range of the stage is not limited, but the reported orientation of the stage is always expressed as a value between 0° and 359.99°. The minimum incremental movement of the stage is 288.0 µrad, and it can be positioned with a repeatability of 434 µrad in response to signals from the magnetic sensor.

The stage learns to efficiently position itself precisely using a position error compensation algorithm. After the stage moves into a new position, it detects the error between the requested and actual positions. The position of the stage is then corrected, and an error compensation value is calculated. The algorithm is then updated with the error compensation value, so that it is applied when the stage is move to its next position. Typically, an optimum error compensation value is found after between two and six movements.

Resonance Frequencies

On power-up, the factory default setting instructs each motor driving the rotation stage to search for the resonance frequencies that will deliver the best performance. During this process, the rotation stage will translate a forward and backward by a small amount. If movement on start-up is undesirable, it is possible to disable this calibration procedure by using the serial port to initialize the frequencies on power-up. A new search for optimal resonance frequencies may be performed at any time; to maintain optimal performance, it is recommended that new searches be performed after changes in loading and/or ambient temperature. Please see the manual for details.

The Components of the Elliptec Motor
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The Components of the Elliptec Motor
The Elliptec Piezoelectric Resonant Motor
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The Elliptec Piezoelectric Resonant Motor

The Elliptec™ Piezoelectric Resonant Motor

Thorlabs' Elliptec™ piezo resonant motor, shown at right, is lightweight, with a mass of 1.2 g, and compact: the dimensions of the resonator housing, excluding the spring, are 8 mm x 4 mm x 20 mm.

Components of the Motor

The components that compose the motor are shown at far-right. The piezoelectric element is press fit into the aluminum resonator, which has been precisely designed and machined to produce the desired elliptical motion at the tip and to interface optimally with the driven module. The free ends of the spring are integrated with the resonator housing. The wires, which are soldered to the top and bottom of the piezoelectric element, deliver the voltage signal that induces the piezoelectric element to vibrate at ultrasonic frequencies.

When the motor is built into a system, the open loop of the spring is bolted to a sturdy surface that is stationary with respect to the item to be driven, and the tip of the resonator is placed in contact with the item. The purpose of the spring is to maintain constant contact between the tip of the resonator and the driven item, and the direction of motion is determined by the resonance frequency at which the piezo element is driven.

Elliptical Motion and Comparison with Conventional Motors

Elliptec motors quickly and precisely position stages and mounts while never seeming to move. Their microscopic movements occur at ultrasonic frequencies and are invisible to the naked eye.

The motor is operated by driving it at one of its two resonance frequencies. A voltage signal oscillating at an ultrasonic frequency is applied to the piezoelectric chip, which responds by expanding less than a micron and then contracting back to its original dimensions at the frequency of the driving signal. This rapid-cycling change in the chip's dimensions causes a vibration in the aluminum resonator housing. When the vibration is at one of the housing's resonance frequencies, a pushing motion results at the tip of the motor. When the vibration is at the other resonance frequency a pulling motion results.

As illustrated in the video, the pulling and pushing motions result from the tip of the motor tracing an elliptical path in space when the motor operates at resonance. The selected resonance frequency controls the direction of the cyclical motion. The motor's tip traces one half of the ellipse as it expands and the other half as it contracts. When the motor pushes the driven item, the motor's tip is in contact with the item while the tip expands; the two are not in contact while the tip contracts. The converse is true when the motor pulls the driven item in the opposite direction. The total displacement at the tip of the motor is a function of both the mechanical load it is driving and the voltage supplied to the piezo element. The maximum displacement can be up to a few microns when the peak driving voltage is 5 V.

The motor behaves in many ways like a DC or electromagnetic stepper motor, but it does not suffer from many of the drawbacks of these conventional motors. Unlike conventional electromagnetic motors, which must overcome inertial delays to come to a stop, the highly dynamic Elliptec motor can stop within microseconds. As it has no gears, it does not exhibit backlash. Since it possesses no magnets, it is compatible with use in environments sensitive to electromagnetic interference. The motion of the driven element is continuous and smooth. As the tip of the motor must be in contact with the driven item to induce motion, the motor possesses the safety feature of an inherent friction brake. When in contact with a plastic surface, the motor operates virtually silently.

For OEM applications, the motor can be manufactured in volume at low cost, and it can be driven by inexpensive analog electronics. It does not require microprocessors or software; however it is compatible for use with them.

Screen Capture of the Elliptec Piezoelectric Resonant Motor Control Software GUI
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The Elliptec Piezoelectric Resonant Motor Control Software GUI

Software for Devices Driven by Elliptec™ Piezoelectric Resonant Motors

All devices based on the Elliptec™ resonant piezo motor may be controlled by the Elliptec system software, which features an intuitive graphical user interface (GUI). The source code, in C# format, is included in software bundle available for download, and custom applications can be created in any language. The image at right shows a screen capture of the GUI, and the button that follows links to the download page.

Commands are entered in the Sequencer command / wait order section located at the center-left of the GUI. An example of a sequence of commands that might be sent to the device is "Aho0" to move to the rotation stage at address "A" to the home position in the clockwise direction, and then "Afw" to move the stage at address "A" forward by the jog increment. The command "As1" is used to perform the frequency search that will identify the optimal resonant frequencies, for the current operating conditions, for Motor 1 at adddress "A." 


Version 1.5.0

Includes the Elliptec System Software, with an easy-to-use GUI. Also available for download is the Communications Protocol manual, which details the communication commands for the Elliptec software package.

Software Download

Posted Comments:
user  (posted 2019-05-23 12:46:40.18)
Could you give a bit more detail about the networked operation of two stages from a single USB port? Do I need two interface boards? Exactly how should I daisy-chain things together in this scenario? Could you also explain what practical consequence having a larger value for bi-directional accuracy than repeatability means? If we are looking to calibrate something as a function of the angle read by the stage, am I right to assume that it is the repeatability that matters rather than accuracy?
rmiron  (posted 2019-05-24 11:22:40.0)
Response from Radu at Thorlabs: You can control up to 16 daisy-chained Elliptec stages (of various types) via a single interface board. I will contact you directly in order to send you a guide for how to make a custom daisy-chaining cable. Every different stage connected to the interface will have a different address byte, with values ranging from 0 to F. You can identify the address byte of a particular stage either from our ELLO software or by trial and error (sending a serial command and checking whether any stage responds). Accuracy refers to the difference between the settled position after a move and the true position. Repeatability refers to the possible variation in settled positions when the same position is demanded multiple times in a single session. The former is much larger because it includes the homing accuracy. Because the travel is encoded, most of the inaccuracy comes from homing. After homing, the encoder doesn't allow the positional error to keep building up to large values. However, because it assumes the position at which the stage homed to be the true 0 position, the accuracy of the stage's moves will always include that homing accuracy.
victor.lorenz  (posted 2018-09-21 14:13:30.68)
By mistake I recently ordered the ELL8/M instead of the ELL8K/M (sales order MS3309025). . I wonder if I could order separately the missing Interface Board, Power Supply, Brackets and Cables. If so, how should I proceed when I made my new order to add these items? If this is not the place for such request, who should I contact?
rmiron  (posted 2018-09-24 06:45:18.0)
Response from Radu at Thorlabs: Hello Victor. There is no need to worry about this. We will send you a quotation for the missing parts. The total price for them will equal the price difference between ELL8K/M & ELL8/M.
user  (posted 2018-08-13 17:03:42.67)
Hi, I'm trying to use an ELL8M for a scanning application where scanning time is key. Therefore I'd like to avoid stepped acquisition. Is it possible to stream out the encoder data during a continuous rotational movement?
rmiron  (posted 2018-08-16 11:34:00.0)
Response from Radu at Thorlabs: Unfortunately, this is not possible. The stage does not have any pins that are relaying the encoder's signal. With that being said, it would be a good idea to add one and I'll advertise your idea internally. The possibility to read the encoder pulses directly would greatly increase the Elliptec stages' suitability in fast scanning applications.
b.kettle  (posted 2018-01-19 16:49:03.943)
Hello, I recently purchased two Elliptec rotation stages; the ELL8K/M bundles. However I am having trouble getting both to run in tandem, or networked. I can't seem to find much information in the supplied manuals. I can successfully connect both stages to my PC using the separate control boards and usb cables, however these interface using two different COM ports, which the software doesn't accommodate. The manual does mention in this process to connect the second stage to the first stage, however mechanically there seems like no connections supplied to do this task. The stage PCB only has one connector, which runs to the one connector on the drive board, which has the usb straight to the computer. No means of linking them together. Can you please offer any advice on the situation? I like how the motors operate, but need to be able to control both stages from the one software window (and hence one set of sequences). Thank you in advance for any help.
bwood  (posted 2018-01-22 09:02:14.0)
Response from Ben at Thorlabs: Thank you for your feedback. You can operate up to 16 Elliptec devices at the same time, by daisy chaining the control boards together. In this setup, all of the devices are connected through one USB port. To do this you will need to create a custom cable, with several connectors installed along its length. The cable standard we use is the Molex Picoflex series with PF-50 sockets, we can suggest Farnell as a good local supplier of parts to do this.
gpu  (posted 2017-10-04 14:38:21.78)
Hi, I bought such a stage but was'nt careful during the setup and crashed it against a breadboard. For some reason, this damaged the elastomer track and 3 mm are now indented such that the motors can't reach it. Is it possible to get the track as a spare part?
bwood  (posted 2017-10-17 05:06:30.0)
Response from Ben at Thorlabs: I am sorry to hear about our issues here. I will be in direct contact with you to assess the damage to your stage.
garrett.farrell  (posted 2017-09-11 09:32:08.9)
Hi , Is the Ellptec rotation stage controllable under LabView and if so do you have an example VI Many thanks
awebber-date  (posted 2017-09-13 04:23:13.0)
Response from Alex at Thorlabs: Yes, you are able to control any of our Elliptec products using LabView, however there are no VIs. You can download the communications protocol .pdf file by clicking on the "Software" tab and then on the software button. Then navigate to the "Communications Protocol" tab and there you can download it.
andrey  (posted 2017-04-05 11:59:59.973)
Hi! I'm testing this product if it can be used in my application. I do need to control the moving velocity. The "set velocity" command ("sv" doesn't help). The wheel does move slower but this decreases significantly the rotating momentum and it even cannot move itself at values 40% and less. Moving by small steps with short intervals could work for me, but when I'm trying to it this way by sending commands to the serial port. I cannot do more than 1 step in 300 ms. This is the most important problem for me. Is there a way to control the rotational speed? There are some more that I described below. But for me they are not significant. There are some "features" that actually look for me as bugs. There is a difference between that described in the communication protocol and the way the controller actually acts. If a moving takes a long time, the controller doesn't reply on a "ma" or "mr" message until the moving ends although it should reply with "GS" message. If I want to move it for a long distance (720 deg, moving can be longer than 2 seconds depending on load) it returns "Mechanical time out" error. Communication speed depends very much on the controller address. Sending "ma" message and getting a response takes ~300ms with controller address 0 and around 1s with address F. Only one controller used in both cases.
bwood  (posted 2017-04-13 03:53:22.0)
Response from Ben at Thorlabs: Thank you for your feedback. The Elliptec technology and their evaluation kits, while low cost and low profile, do have some design aspects to be aware of. Unfortunately, in this case the ELL6 is not suited for low velocity applications, apart from the "set velocity" command there isn't another effective method of lowering the velocity. To address your other points, I believe the first two points are related to moving a long distance. The stage is not meant for for continuous rotation, so the stage may be timing out or sending back the error code GS. The responce time will vary depending on whether the stage is busy or not, when the message is sent. Finally, I would note that these limitations are in part due to the fact this is an economical evaluation kit to demonstrate the technology, if you have a particular application in mind we are more than happy to discuss custom devices for OEM applications. If you would like to discuss this, or the device in more detail, please feel free to contact me at
albert.romann  (posted 2017-02-08 04:34:30.603)
Hi, can it be mounted vertically (to drive an ND filter wheel)? Is there a drawback?
tcampbell  (posted 2017-02-08 09:29:20.0)
Response from Tim at Thorlabs: thank you for your feedback. This rotation stage should not be mounted vertically. The motor is not suited to operate in that orientation.
dale.fried  (posted 2016-12-19 20:49:44.823)
I would love to see this made with a 12.5mm clear aperture into which I could mount a waveplate.
bhallewell  (posted 2016-12-28 03:31:06.0)
Response from Ben at Thorlabs: Thank you for your contacting us. This is an Elliptec product idea which we are planning to release in the coming year. Our OEM team will contact you to start a discussion about your needs.
amiller  (posted 2016-10-12 19:25:52.237)
Hi, Great device; I am intereted in an OEM application where I need ~10x (0.002 deg accuracy+ repeatibility) better resolution. Are the current limitations on the accuracy of the device imposed by the actuator or by the encoder. If the latter we would be interested in discussing approaches to developing a custom solution. Thank you! -Tony
bwood  (posted 2016-10-13 08:14:22.0)
Response from Ben at Thorlabs: Thank you for you interest in our Elliptec motor technology. We welcome OEM customisation in our Elliptec driven devices, and we can potentially meet your requirements with upgraded encoders and other components. A member of our OEM team will be in contact with you shortly, to further discuss your requirements, and how we can meet them.

Rotation Mount and Stage Selection Guide

Thorlabs offers a wide variety of manual and motorized rotation mounts and stages. Rotation mounts are designed with an inner bore to mount a Ø1/2", Ø1", or Ø2" optic, while rotation stages are designed with mounting taps to attach a variety of components or systems. Motorized options are powered by a DC Servo motor, 2 phase stepper motor, or an Elliptec™ resonant piezo motor. Each offers 360° of continuous rotation.

Manual Rotation Mounts

Rotation Mounts for Ø1/2" Optics
Item # MRM05(/M) RSP05(/M) CRM05 PRM05(/M)a SRM05 KS05RS CT104
Click Photo
to Enlarge
Features Mini Series Standard External SM1
(1.035"-40) Threads
Micrometer 16 mm Cage-Compatible ±4° Kinematic Tip/Tilt Adjustment Plus Rotation Compatible with CT1 Cage Translator Stage and 1/4" Translation Stagesb
Additional Details
  • This mount is available in the PRM05GL5 bundle, which includes the PRM05 rotation mount with the SM05PM5 polarizing prism mount.
  • The CT104 is complatible with the 1/4" translation stages using our MS103(/M) adapter plate.
  • The CT104 is compatible with the CT1 cage translation stage, which is designed for use with 30 mm cage systems.

Rotation Mounts for Ø1" Optics
Item # RSP1(/M) LRM1 RSP1D(/M) DLM1(/M) CLR1(/M) RSP1X15(/M) RSP1X225(/M) PRM1(/M)a
Click Photo
to Enlarge
Features Standard External SM1
(1.035"-40) Threads
Adjustable Zero Two Independently Rotating Carriages Rotates Optic Within
Fixed Lens Tube System
Continuous 360° Rotation
or 15° Increments
Continuous 360° Rotation
or 22.5° Increments
Additional Details
  • This mount is available in the PRM1GL10 bundle, which includes the PRM1 rotation mount with the SM1PM10 polarizing prism mount.

Rotation Mounts for Ø1" Optics
Item # LM1-A &
Click Photo
to Enlarge
Features Optic Carriage Rotates Within Mounting Ring 30 mm Cage-Compatiblea 30 mm Cage-Compatible
for Thick Opticsa
30 mm Cage-Compatible
with Micrometera
±4° Kinematic Tip/Tilt Adjustment Plus Rotation Six-Axis
Kinematic Mounta
Additional Details
  • This mount also features four 4-40 (M3) holes on the rotation dial for use with the K6A1(/M) prism platform.

Rotation Mounts for Ø2" Optics
Item # RSP2(/M) RSP2D(/M) PRM2(/M) LM2-A &
Click Photo to Enlarge
Features Standard Adjustable
Micrometer Optic Carriage Rotates Within Mounting Ring 60 mm Cage-Compatible ±4° Kinematic Tip/Tilt Adjustment Plus Rotation
Additional Details

Manual Rotation Stages

Manual Rotation Stages
Item # RP005(/M) MSRP01(/M) RP01(/M) RP03(/M) QRP02(/M)
Click Photo
to Enlarge
Continuous Rotation Mount
Features Standard Two Hard Stops
Additional Details


Manual Rotation Stages
Item # XRR1(/M) PR01(/M) CR1(/M) XYR1(/M) OCT-XYR1(/M)
Click Photo
to Enlarge
Features Fine Rotation Adjuster and
3" Wide Dovetail Quick Connect
Fine Rotation Adjuster and
SM1-Threaded Central Aperture
Fine Pitch Worm Gear Rotation and 1/2" Linear XY Translation
Additional Details
  • The stage profile is higher when it is mounted using the screw slots rather than stacked on another stage or accessory with 3" dovetails.
  • The OCT-XYR1(/M) stage includes the XYR1A solid sample plate. This plate can be detached from the stage to reveal the same mounting features present on the XYR1(/M) stage.

Motorized Rotation Mounts and Stages

Motorized Rotation Mounts and Stages
Item # DDR25(/M) K10CR1(/M) PRM1Z8(/M)a PRMTZ8(/M)b DDR100(/M) HDR50(/M) ELL18(/M)c
Click Photo
to Enlarge
Features Compatible with
SM05 Lens Tubes,
16 mm Cage System,
30 mm Cage System
Compatible with SM1 Lens Tubes and
30 mm Cage System
Tapped Mounting Platform for Mounting Prisms or Other Optics Compatible with
SM1 Lens Tubes,
16 mm Cage System,
30 mm Cage System
Compatible with
SM2 Lens Tubes
Tapped Mounting Platform, Open Frame Design for OEM Applications
Additional Details
  • This stage is available in the KPRMTE(/M), which includes the PRMTZ8(/M) Motorized Rotation Stage with the KDC101 K-Cube DC Servo Motor Controller.
  • This stage is available in the KPRM1E(/M), which includes the PRMT1Z8(/M) Motorized Rotation Stage with the KDC101 K-Cube DC Servo Motor Controller.
  • This stage is available in the ELL18K(/M), which includes an interface board, mounting brackets, and connectors for PC control.

Rotation Stage Bundle

The Tips of the Motors Contacting the Edge of the Rotation Stage
Click to Enlarge

The motors' aluminum tips contact the black plastic track encircling the rotation stage. This track should not be touched to prevent debris and oil building up on the track.
Application Idea Using Rotation Stage
Click to Enlarge

View Imperial Product List
Item #QtyDescription
ELL18K1Rotation Stage Bundle: ELL18 Stage, Interface Board, Power Supply, Brackets, Cables
VA1001Adjustable Mechanical Slit, 8-32 Tap, Imperial Micrometer
MB61Aluminum Breadboard 6" x 6" x 1/2", 1/4"-20 Taps
GR25-12051Ruled Reflective Diffraction Grating, 1200/mm, 500 nm Blaze, 25 x 25 x 6 mm
CH1A1Fixed Cylindrical Lens Mount, Max Optic Height: 1.60" (40.6 mm)
TR11Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 1"
PH11Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 1"
SH25S10011/4"-20 Stainless Steel Cap Screw, 1" Long, Pack of 25
W25S05011/4" Washer, M6 Compatible, Stainless Steel, Pack of 100
View Metric Product List
Item #QtyDescription
ELL18K/M1Rotation Stage Bundle: ELL18/M Stage, Interface Board, Power Supply, Brackets Cables
VA100/M1Adjustable Mechanical Slit, M4 Tap, Metric Micrometer
MB1515/M1Aluminum Breadboard, 150 mm x 150 mm x 12.7 mm, M6 Taps
GR25-12051Ruled Reflective Diffraction Grating, 1200/mm, 500 nm Blaze, 25 x 25 x 6 mm
CH1A1Fixed Cylindrical Lens Mount, Max Optic Height: 1.60" (40.6 mm)
TR20/M1Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 20 mm
PH20/M1Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=20 mm
SH6MS251M6 x 1.0 Stainless Steel Cap Screw, 25 mm Long, Pack of 25
W25S05011/4" Washer, M6 Compatible, Stainless Steel, Pack of 100
ELL18K/M Rotation Stage Bundle used to Orient a Grating With Respect to a Variable Slit
  • Ideal for OEM Evaluation Testing
  • Easily Integrate into a Setup
  • Operate using Manual and/or Computer Control
  • Included Power Supply is Required for Powering the Stage

The Rotation Stage Bundle is a complete package that includes the ELL18/M rotation stage. The ELL18K/M package facilitates quick integration of the rotation stage into laboratory setups and other experimental applications. It also provides a convenient means to evaluate incorporating this technology into OEM applications.

The tips of both motor housings are in firm contact with the rubber track encircling the rotation stage, as can be seen in the image at the far-right. The motors are installed with opposite orientations and clockwise (and counterclockwise) rotation occurs when one motor pushes the track forward while the other pulls it backward. 

Included in the ELL18K/M Bundle
ELL18/M Rotation Stage 5 V Power Supply with Region-Specific Power Adapter
Interface Board 8-Conductor 28 AWG Ribbon Cable and USB Cable
Mounting Brackets PC-Based Software for Download
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
ELL18K Support Documentation
ELL18KRotation Stage Bundle: ELL18 Stage, Interface Board, Power Supply, Brackets, Cables
+1 Qty Docs Part Number - Metric Price Available
ELL18K/M Support Documentation
ELL18K/MRotation Stage Bundle: ELL18/M Stage, Interface Board, Power Supply, Brackets Cables

Rotation Stage

Features of the Rotation Stage
Click to Enlarge

Features of the Rotation Stage

This Rotation Stage is offered to meet the needs of applications whose designs require multiple networked Elliptec resonant motor products. It possesses a Ø1.97" (Ø50.0 mm) top surface functionalized with 37 tapped 8-32 (M4) mounting holes with 6 mm deep threads. Details describing the dimensions, including the spacing of the threaded holes, and other specifications of the stage are given in the Specs tab. Please contact us to discuss customizing the rotation stage, or to arrange to purchase mounting brackets with the stage.

The PCB of the rotation stage incorporates a male 8-pin Picoflex connector (header). Each ELL18(/M) stage ships with the female 8-pin Picoflex connector (receptacle) that mates with the connector (header) on the board.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
ELL18 Support Documentation
ELL18Rotation Stage: Ø1.97" Platform, 37 Tapped 8-32 Mounting Holes
+1 Qty Docs Part Number - Metric Price Available
ELL18/M Support Documentation
ELL18/MRotation Stage: Ø50.0 mm Platform, 37 Tapped M4 Mounting Holes
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