Manual Drives, 1" and 2" Differential Actuators

Overview
DM12 Knob Attachment
DM12 Operation
Feedback

Specifications
Item #	DM12	DRV8
Coarse Adjustment Range	1.0" (25.4 mm)	2.0" (50.8 mm)
Coarse Adjustment Pitch	0.5 mm	0.5 mm
Fine Adjustment Range	250 µm	300 µm
Fine Adjustment Pitch	25 µm with 0.5 µm Graduations	0.05 mm with 1 µm Graduations

Thorlabs offers a number of Manual Drives for use with RollerBlock Stages. These drives in paticular can be fitted to components with a standard 3/8" or 0.5" mounting barrel.

Fine Adjustment Knob Reattachment for 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 2019-10-25 10:47:46.153)

What is the load capacity for DRV8? Is it same with DM12?

cwright (posted 2019-10-25 07:52:51.0)

Hello and thank you for your question. The load capacity for the DRV8 should be 10 kg.

user (posted 2019-05-22 09:02:52.713)

Hi. Does the locking screw prevent rotation of the differential fine adjuster, or only the macro adjuster? Thanks

AManickavasagam (posted 2019-05-23 06:15:05.0)

Response from Arunthathi at Thorlabs: Thanks for your query. The locking screw fixes only the Macro/coarse adjuster position. This is to avoid cross coupling between the coarse and fine adjustment mechanism.

georgy.onishchukov (posted 2018-02-14 09:15:03.93)

Dear Sir/Madam, do you have any instruction about cleaning and especially lubricant to be used for smearing of the actuators? We have problems that turning need too much force to be applied because of hardening of the grease in the thread. Regards, Georgy georgy.onishchukov@fau.de

llamb (posted 2018-02-20 09:13:46.0)

Hello, thank you for contacting Thorlabs. You can clean the differential adjuster and its threads with acetone, and then apply Apiezon grease for lubrication.

matthias.lange (posted 2013-12-12 02:24:06.083)

Hi, what is the Load Capacity of the DM12 Micrometer Head? Best regards, Matthias

jlow (posted 2013-12-17 02:09:34.0)

Response from Jeremy at Thorlabs: We recommend the load to be <15lbs for the DM12.

Manual Drives, 1" Differential Adjuster

Manual Drives, 1in Differential Adjuster

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Click to Enlarge

Standard Ø3/8" Mounting Barrel
High Resolution as Well as Coarse
Adjustment in One Small Package
Differential Adjustment Knob Graduated
to Aid in Keeping Track of Position

The DM12 Differential Adjuster uses two leadscrews; one pushes the center spindle forward at 400 µm per revolution, while the other pulls it back at 375 µm per revolution. The resultant total forward motion of the center spindle is just 25 µm for each complete revolution of the graduated knob. Each small graduation of the fine control knob is 0.5 µm; the smallest incremental move for the DM12 is approximately 0.5 µm. The coarse travel is lockable via a thumbscrew located on the 3/8" mounting barrel. Also available is the DM10 1/2" Differential Adjuster. For more details on the operating mechanism of the DM12, please refer to the DM12 Operation tab.

If the fine adjustment knob on the DM12 is ever removed from the actuator body, it can be reattached. Please see the DM12 Knob Attachment tab for more details. Follow the reattachment instructions carefully so that the actuator functions properly.

Manual Drives, 2" Differential Adjuster

Manual Drives, 2in Differential Adjuster