Manual Drives, 1/2" Differential Actuators


  • Coarse & Fine Adjustment
  • Standard 3/8" (9.5 mm) Mounting Barrel

DM10

DRV304

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These differential adjusters are designed for use on stages with a 9.5 mm (3/8") mounting clamp. The DRV304 is ideal for updrading our RB13M 3-axis RollerBlock stage to differential drives. The DM10 is for use with our MT1 and MT3 stages.

See the presentations below for more details.

Fine Adjustment Knob Reattachment for DM10 Differential Adjusters

  • Step 1: Fully remove the detached knob.
  • Step 2: Apply pressure to the tip of the actuator.
  • Step 3: While maintaining pressure, screw in the knob 2 to 3 threads.
  • Step 4: Once threaded, remove pressure from Step 2 and continue to slowly screw in the knob. Please note that this should be done slowly and with little force. If too much force is applied, cross-threading may occur and may damage the threads.

Differential Adjuster Operation Mechanisms

A differential adjuster consists of four basic parts: outer body, coarse adjustment lock, inner spindle, and fine adjustment knob. Using the DM22 as an example, the video to the left demonstrates how these four parts come together to create a device that allows for coarse and fine adjustments. Also detailed are two different methods of mounting these actuators into an assembly.

Differential Adjuster Mechanisms

  • Outer Body:
    • Provides Coarse Adjustment
    • Contains Internal Threads with a Pitch Smaller than the External Threads of the Inner Spindle
  • Coarse Adjustment Lock:
    • Prevents the Outer Body from Rotating; Locks Coarse Translation
    • Enables Fine Adjustment
  • Inner Spindle: 
    • Mounted within Outer Body
    • Contacts the Moving Platform and will Translate with the Coarse Adjuster
    • Contains External Threads with Greater Pitch than the Internal Threads of the Outer Body
  • Fine Adjustment Knob:
    • Internal and External Threads that Match the Inner Spindle and the Outer Body Threads
    • Rotating the Knob Provides Inner Spindle Translation that is Equal to the Difference Between the Two Thread Pitches

Posted Comments:
user  (posted 2019-06-28 21:01:01.027)
What is the maximum axial load capacity of DRV304?
AManickavasagam  (posted 2019-07-01 11:24:51.0)
Response from Arunthathi at Thorlabs: Thanks for your query. Unfortunately, we do not have a spec for the Axial load capacity of the actuator. However, I have contacted you directly to get further details on the load and stage you intend to use with the actuator which would help to determine the feasibility for your setup.
andreas.ahlrichs  (posted 2018-03-19 16:22:12.26)
Hi, what is the load capacity of the DM10 Differential Actuators? Best regards
YLohia  (posted 2018-03-30 02:31:50.0)
Response from Yashasvi at Thorlabs USA: Thank you for contacting Thorlabs. From our testing, we have determined that any more than 15 lbs of axial load will result in the loss of resolution of this actuator.
lesundak  (posted 2014-08-18 12:37:32.23)
Hi. Adjuster DM10 does not work well. Fine adjuster knob together with movable spindle are lose. With a little pressure on the knob, movable spindle is moving according to coarse adjustment/mounting barrel part. The movement is no more than 0.5 mm, but it can be seen in all positions of fine adjuster and it makes the adjuster unusable. Can this be somehow repaired?
jlow  (posted 2014-08-21 09:41:02.0)
Response from Jeremy at Thorlabs: It sounds the knob is not screwed in properly. We will contact you to send this in for repair.
stephen.nanchy  (posted 2014-03-21 16:02:54.217)
Please: where can I find instructions for resetting a DM10? Someone completely unscrewed the knob. The threads are undamaged - no tried to put it back on again. Thanks!
jlow  (posted 2014-03-21 04:57:32.0)
Response from Jeremy at Thorlabs: You just need to screw the knob back on carefully. Do not force it in if you feel some resistance. I will make a short video and send it to you.

Manual Drives, 1/2" Differential Micrometer

DRV304 Differential Micrometer
  • Designed for Use with Our RollerBlock Stages
  • 1/2" (13 mm) Coarse Travel
  • 5.0 µm Coarse Resolution
  • 300 µm High Resolution Differential Travel
  • 0.5 µm Differential Resolution
  • Ø3/8" Mounting Barrel

The DRV304 Differential Micrometer uses a unique mechanism that converts a relatively large displacement into a relatively small displacement of the center fine adjustment spindle. The design has the additional benefit of providing a uniform, smooth feel that is largely independent of loading. Coarse adjustment is provided via a knurled knob, while the differential adjuster features a large rubber grip which adds to the overall sensitivity of the unit. The coarse adjustment knob gives 13 mm of total travel with 5.0 µm resolution while the differential knob provides 300 µm of total travel with 0.5 µm resolution. The Ø3/8" mounting barrel is compatible with a host of standard mounting equipment.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
DRV304 Support Documentation
DRV304Differential Micrometer Drive, 1/2" (13 mm) Travel
$484.48
3 weeks

Manual Drives, 1/2" Differential Adjuster

  • Designed Specifically for use in our 1/2" Travel Stages
  • Coarse Adjustment: 1/2" (12.7 mm)
  • Fine Adjustment: 250 µm Range, 25 µm per Revolution

The DM10 Differential Adjuster uses two internal leadscrews; one pushes the center spindle forward at 400 µm per revolution, and one pulls it back at 375 µm per revolution. The resultant total forward motion of the center spindle is just 25 µm per one complete revolution of the graduated knob. For more details on the operating mechanism of the DM10, please refer to the DM10 Operation tab.

Each graduation of the fine control knob is 0.5 µm. The coarse adjustment provides 1/2" of travel with a screw pitch of 0.5 mm, which is lockable via a thumbscrew located on the mounting barrel.

If the fine adjustment knob on the DM10 is ever removed from the actuator body, it can be reattached. Please see the DM10 Knob Attachment tab for more details. Follow the reattachment instructions carefully so that the actuator functions properly.

If a longer travel range is needed we also offer our DM12 1" Differential Adjuster.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
DM10 Support Documentation
DM10Differential Adjuster For Translation Stages, 1/2" Travel
$144.41
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