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
- Designed for Use with Our RollerBlock Stages
- Coarse Adjustment: 1/2" (13 mm) Travel, 0.5 mm per Revolution
- Coarse Resolution: 5.0 µm
- Fine Adjustment: 300 µm Travel, 50 µm per Revolution
- Fine Drive Resolution: 0.5 µm
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 1/2" (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.
- Designed Specifically for Use in Our 1/2" Travel Stages
- Coarse Adjustment: 1/2" (12.7 mm) Travel, 0.5 mm per Revolution
- Fine Adjustment: 250 µm Travel, 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.