Manual Drives, 1" and 2" Differential Actuators
- Compatible with a Wide Range of Stages
- Coarse Travel & High Resolution Adjuster in One Package
- Ø3/8" & Ø1/2" Mounting Barrels
- Ideal For OEM Applications
|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
- 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.
- 2" (50 mm) Travel
- Non-Rotating Tip
- 0.5 µm Resolution
- Ø1/2" (12.7 mm) Interchangeable Brass Mounting Bushing
- Coarse Adjustment: 500 µm/rev
- Fine Adjustment: 50 µm/rev
This differential drive has been designed for use with single-axis stages equipped with a Ø1/2" (Ø12.7 mm) actuator mounting clamp. The large-diameter differential drive actuator provides fine, ultra-smooth control over motion. The fine adjuster delivers 50 µm of travel per revolution with 1.0 µm graduations. The removable brass bushing allows this actuator to be used in any OEM application requiring 2" (50 mm) of overall travel.