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Understanding Vertical Linear Stage Specifications
Specifications | Description | |
Model Number | ZM07A-S3K | 1. Kohzu's significant alpha-numeric model numbers offer quick product insight. |
Table Size | 70mm x 70mm | 2. Table size refers to the stage's upper-most mounting surface. |
Guide Mechanism | Cross-Roller Bearing | 3. Type of guide mechanism used on this stage. |
Motion Range | ±3mm | 4. Stage travel range in the positive and negative directions from it's centered or neutral position. Differential actuator types will indicate total coarse and fine travel ranges respectively. |
Straightness | ≦ 4μm / 6mm | 5. Straightness is measured relative to mounting surface. See page 296 for detail. |
Minimum Readout | Fine 0.25μm | 6. Minimum readout is the smallest measurable actuator motion increment. |
Load Capacity (Horizontal) | 3kg | 7. Maximum load capacity is for a horizontally orientated stage with load centered on top-plate. |
Material | Aluminum Alloy | 8. Material specification is for stage's main body components only. |
Finish | Clear-Matte Anodizing | 9. Surface finish type and color. |
Weight | 900g | 10. Stage weight includes all components depicted in product photograph. |
Actuator | Fine Pitch Positioner FPP03-13 (13mm) | 12. Actuator model number and travel range. |
Guide Mechanism Type
Cross-Roller Bearing Guides
In cross-roller bearing guides,,, quench hardened and precision ground bearing surfaces move upon loose hardened steel cylinders (rollers) with rotation axes oriented in alternating 90 degree angles. Having rollers arranged in an alternating cross pattern allows preloading and operation at any angle. The roller bearings are held apart from one another by a bearing cage, which prevents adjacent rollers from touching. Since cross-roller bearings have little difference between static and dynamic friction they minimize start-to-stop slip-motion typical of other bearing types. The line contact of roller bearings along with precise roller-to-race gap management provide larger loadbearing surfaces, higher preloads and meet very tight runout and stiffness specifications.
Wedge Type Cross-Roller Guides
One set of wedge type cross-roller guides are mounted on the horizontal plane and the other set of guides are tilted so that tangent is 1/4 (approximately 14°) (see Fig. 1). If the wedge is pushed in from one side, the table fixed to the central axis moves vertically. Since the tilted cross roller guide supports the horizontal component of force, the moment load rigidity on the table top face is reinforced.
Feeding Mechanism
Micrometer
This system converts the horizontal force of the micrometer head to a vertical force and moves the stage vertically by means of a lever (see Fig. 2). The basic structure is the same for all types. Two stage plane sizes, 50 mm x 50 mm and 70 mm x 70 mm, and two actuators, the micrometer head and fine pitch positioner are available.
Rack and Pinion
This system decelerates torque from the handle by means of a worm and a worm wheel and converts it to vertical force by means of the rack and pinion that moves the stage vertically (see Fig. 3). Normal and high withstand load types are available.
Wedge type cross-roller guides
This system converts the horizontal force of the micrometer head to a vertical force by means of a 1/4-wedge and moves the stage vertically (see Fig. 1 on the previous page). The basic structure is the same for all types. Two stage plane sizes, 70 mm x 70 mm and 100 mm x 100 mm, and two actuators, direct connection of the handle-wheel rotation to the driving ground screw and a fine pitch positioner for pushing the wedge, are available.
Travel Distance
With the ZM05A-C1K and bracket type vertical liner stage, the micrometer measurement display matches the actual movement distance. With other stages, the display may not accurately match the actual movement distance.
Micrometer
The force that is generated by pushing with the micrometer head is converted to a vertical force by means of a lever (see Fig. 2). The precise movement distance is indicated by a function of distances from the fulcrum of the lever to the power point and to the action point, and by the shape of the micrometer head tip. The vertical movement distance is approximately 1/2 of the micrometer head movement distance.
Rack and Pinion
The driving force from the handle is decelerated by means of a worm and a worm wheel and converted to a vertical force by means of the rack and pinion system (see Fig. 3). This type is designed so that one rotation of the handle-wheel corresponds to 0.5 mm and one division of the scale corresponds to 10 μm of vertical movement.
Wedge Type Cross-Roller Guides
The upper stage moves vertically by either of two means: the ground screw that is directly connected to the handle or by inserting a wedge to the fine pitch positioner (see Fig. 1 on the previous page). Since the vertical-to-horizontal ratio of the wedge is 1:4, the vertical movement distance is 1/4 of the wedge push-in depth. For the handle-wheel type, one rotation corresponds to 0.125 mm and one division of the scale corresponds to 5 μm of movement. For the fine pitch positioner type, coarse adjustment can be made in 0.25 mm increments and fine adjustment in 0.125 μm increments.
Bracket Type Vertical Linear Stage
Bracket Type Vertical Linear Stage
The bracket type vertical linear stage has an X-axis stage customized to a stand type.
Typically, to suppress any influence from the stage top face, the feed mechanism is mounted on the stage bottom plate. If the stand type is used with this mounting configuration, a load is applied along the spring extension of the stage and the stage height may drop due to gravity (as shown in the left part in the right figure). Consequently, when mounting the stage along the vertical axis as with the bracket type Vertical stage, actuator mounting position must be modified so that force is always applied to the tip of the micrometer head (see the right part in the right figure).