PI V-308 Voice Coil PIFOC Objective Focus Drive Review: Specs, Price and Applications
V-308 is a vertical objective-focus positioner with a voice-coil motor, crossed-roller guide and adjustable magnetic weight compensation. The current V-308.753030 specification provides 7 mm travel with user-adjustable travel limitation and compensation for a load up to 1 kg under the documented orientation. Objective holders and adapters must be specified separately.
Quick Verdict
Consider V-308 for fast microscope focus or surface inspection when the objective mass and optical geometry fit its load and travel. Its 1 nm feedback resolution is separate from 10 nm minimum incremental motion and from travel-wide positioning accuracy. Small-step settling figures apply only to their stated step and error band.
PI V-308 Voice Coil PIFOC Objective Focus Drive at a Glance
Specification | Details |
Travel | 7 mm; adjustable limitation to total 1–7 mm |
Drive / guide | Voice coil / crossed roller with cage control |
Weight compensation | User-adjustable magnetic compensation up to 1 kg in specified arrangement |
Sensor resolution | 1 nm incremental linear feedback |
Minimum incremental motion | 10 nm typical |
Settling example | 15 ms for 100 or 250 nm step in±15 nm error band under stated conditions |
Motor force | 4.2 N typical;9.45 N peak in documented direction scope |
Design and Engineering Assessment
Weight compensation reduces the continuous motor effort needed to oppose gravity. Adjust it for the actual objective/holder mass and allowed orientation. It is not a universal safety brake and should not be assigned an unverified protective holding function.
A15 ms settling figure for a 100 nm step does not describe a 7 mm focus jump. Step size, payload, controller and error band determine the transient. Evaluate the actual acquisition sequence and focus tolerance rather than multiply a small-step result into an unsupported scan throughput.
The table separates 1 nm resolution,10 nm minimum motion and broader calibrated/uncalibrated accuracy. A low-noise encoder cannot remove objective tilt, fixture compliance or optical aberration. Define acceptance in terms of focus quality or metrology performance at the sample.
Configure Objective and Motion Together
Specify objective mass, thread/holder, adapter stack and process travel. Include the complete moving assembly in compensation and moment calculations.
Select the supported voice-coil drive/controller, reference logic and feedback interface. Check the objective’s clearance to the specimen throughout commanded motion and fault recovery.
Accept Imaging and Recovery
Test the actual step sequence with the installed objective and acquisition timing. Measure settling in the error band relevant to imaging, including thermal stabilization.
Save compensation adjustment, travel limits, controller tuning and holder identity. A replacement objective with a different mass or length needs renewed clearance and process checks.
Applications and Selection
Microscopy, wafer/surface inspection and precision objective focusing with a defined optical and mechanical load.
For PI V-308 Voice Coil PIFOC Objective Focus Drive, define the actual machine duty before selecting an ordering configuration. Include the required operating point, available installation space, environment and control interfaces. The specification table describes the product or family; the surrounding machine determines which of those features matters for the intended job.
Price and Value
Price: Request a quote for the exact configuration. Compare the product, compatible control equipment, required mechanical parts, cabling and commissioning as one installed system. A component price alone does not represent the cost of a working automation axis.
Evaluate an alternative against the same duty and acceptance criteria. Match the continuous operating requirement first, then compare transient capability, feedback, mechanical fit and support. This avoids choosing between superficially similar products whose ratings describe different operating conditions.
Pros and Cons
Advantages
Voice-coil focus motion over millimeter travel
Adjustable magnetic weight compensation
Direct fine-resolution feedback
Limitations
Step/settling figures are condition-specific
Objective holders and controller are separate scope
Weight compensation is not automatic machine safeguarding
Who Should Consider PI V-308 Voice Coil PIFOC Objective Focus Drive?
Consider PI V-308 Voice Coil PIFOC Objective Focus Drive when the documented configuration matches the actual process, load, environment and control architecture. Use a representative installed cycle and a defined process-side error budget for acceptance.
PI V-308 Voice Coil PIFOC Objective Focus Drive FAQ
What travels in a V-308 focus application?
The objective/attached load is moved along the configured Z focus axis.
What is the travel?
The current stage lists 7 mm with adjustable limitation to a total 1–7 mm.
What does weight compensation do?
It offsets the specified gravity load to reduce motor effort in the documented arrangement.
Does 1 nm resolution mean 1 nm accuracy?
No. Minimum motion and positioning accuracy are distinct.
Is 15 ms guaranteed for every full-stroke move?
No. The listed example is for a specified small step and error band.
Are objective holders included universally?
No. Specify the actual holder and adapter scope.
Is magnetic compensation a safety brake?
Do not assign a protective holding function without appropriate documented design evidence.
What must change when replacing an objective?
Recheck mass compensation, clearance, moments, tuning and imaging acceptance.
Prices are indicative and may change. Confirm the final configuration, commercial terms and delivery schedule before ordering.
