Understanding Rotation Stage

Understanding Specifications

RA07A-W
RA07A-W
Specifications Description
Model Number RA07A-W  1. Kohzu's significant alpha-numeric model numbers offer quick product insight.
Table Size Φ68mm  2. Table size refers to the stage's valid mounting table size.
Guide Mechanism Bearing 3. Type of bearing mechanism used on this stage.
Motion Range ±135°  4. Stage travel range in the positive and negative directions from it's centered or neutral position.
Lead Mechanism Worm & Worm Wheel 5. Feeding Mechanism and feed screw pitch.
Resolution Full/Half Step 0.004°/0.002°  6. Variation of the stage resolution which is defined by microstep division. 
Micro Step (1/20 div) 0.0002° 
Maximum Speed 20°/sec  7. Maximum Speed of standard stage (half step, 10kpps).
Accumulated Lead Error ≦0.015°/360°  8. Refer the "Inspection System"
Lost Motion ≦0.006°  9. Refer the "Inspection System"
Angular Repeatability ≦0.003°  10. Refer the "Inspection System"
Pitch Error ≦0.01°/4°  11. Refer the "Inspection System"
Backlash ≦0.001°  12. Refer the "Inspection System"
Surface Run out ≦20μm/360°  13. Refer the "Inspection System"
Eccentricity ≦10μm/360°  14. Refer the "Inspection System"
Moment Load Stiffness 0.51 arcsec/N・cm  15. Moment load stiffness is measured in a direction perpendicular to the motion axis.
Load Capacity (Horizontal) 58.8N(6kgf) 16. Maximum load capacity is for a horizontally orientated stage with load centered on top-plate. 
Material Aluminum Alloy 17. Material specification is for stage's main body components only.
Finish Clear-Matt Anodizing 18. Surface finish type and color.
Weight 1.65kg  19. Stage weight includes all components depicted in product photograph.
Standard Motor Five (5) phase stepper motor (Oriental Motor: PX535MH-B) Phase Current 0.75A, Basic Step Angle 0.36° 20. Motorr type of standard stage.
Standard Connector 20Pin Round (Hirose: RP13A-12RA-20PC) 21. Connector type of standard stage.
Stage Wiring Type JH-R  22. Wiring type is connection between stage and stepper motor, and photo-sensor.
Price(JPY) ¥205,000  23. Catalog price in Japanese currency.。 
Overhaul Price * ¥48,000 〜   24. Overhaul price in Japanese currency.
Clean Room Lubricant Change Price ¥36,000  25. Clean Room Lubricant change Price in Japanese currency.
Vacuum Lubricant Change Price ¥36,000  26. Vacuum Lubricant change Price in Japanese currency.
Same Size Motor Change Price ¥12,000 〜   27. Change price of same size motor's mounting as standard motor's in Japanese currency.
Different Size Motor Change Price ¥30,000 〜   28. Change price of different size motor's mounting as standard motor's in Japanese currency.

* Parts price is not included overhaul price.

 

Guide Mechanism Type

●Angular Bearing

The angular bearing has a contact angle appropriate to receive a unidirectional axial load or a combined radial and axial load (see Fig. 1). To use this bearing as a guide system, set two bearings face-to-face on opposite sides. This arrangement provides rigidity for loads both in the radial and axial directions. Figure-1

 

●Cross-Roller Bearing

In cross-roller bearing, quench hardened and precision ground bearing surfaces move upon loose hardened steel cylinders (rollers) with rotation axes oriented in alternating 90 degree angles (Ref. Fig.1). 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 load-bearing surfaces, higher preloads and meet very tight run out and stiffness specifications. Figure-2

Feeding Mechanism

●Worm Shaft & Worm Wheel

The worm wheel is ground at high precision and the worm shaft was processed with a precision abrasive finish (see Fig. 3). Figure-3

Resolution

Resolution of stage RA05A-W, RA07A-W, RA10A-W are calculated based on the following formula.

 

 ΔΘ = Δθ / n・m

ΔΘ: Resolution
Δθ: Basic step angle of motor
n: Reduction ratio of Worm shaft and Worm wheel
m: Division number of micro-step

 

●Tangent-Bar System (Ball Screw)

Rotary movement is generated by applying linear displacement to the bar tip extending from the rotary axis in the tangential direction by means of a ball screw.This is the optimum feed system when the rotation range is small but a fine rotary movement at a high resolution is required.

Resolution

Resolution of tangent-bar style stage RA10A-T is calculated based on the formula below.

 

 ΔΘ =sin-1 (Δθ・P / 360・R・m)

ΔΘ: Resolution
Δθ: Basic step anguler of motor
P: Feed screw pitch
R : Length of tangent-bar (mm)
m: Division number of micro-step


In the case of RA10A-T : R=108mm.
Note: Angular motion is calculated from origin point(0°).

Maximum Speed

Maximum speed depends on motor torque characteristics in higher speed area. However, we calculate maximum speed at 10kpps with motor in half-step mode.

Stage Wiring List

Model Number Wiring Type Photosensor Motor / Phase Current Basic Step Angle Connector Type
 RA04A-W   M2-5C   F-113   PK524HPMB/0.75A   0.36°   20 Pin Round 
 RA05A-W   K1,H3   F-105/F-107   PX535MH-B/0.75A   0.36°   20 Pin Round 
 RA05A-W-R   K1,H3   F-105/F-107   PX535MH-B/0.75A   0.36°   20 Pin Round 
 RA07A-W   JH-R   F-101/F-107   PX535MH-B/0.75A   0.36°   20 Pin Round 
 RA07A-W-R   JH-R   F-101/F-107   PX535MH-B/0.75A   0.36°   20 Pin Round 
 RA10A-T   GH   F-106/F-107   PX535MH-B/0.75A   0.36°   20 Pin Rectangular
 RA10A-T-R   RGH   F-106R/F-107   PX535MH-B/0.75A   0.36°   20 Pin Rectangular
 RA10A-W   JH   F-101/F-107   PK545-B/0.75A   0.72°   20 Pin Rectangular
 RA10A-W-R   JH   F-101/F-107   PK545-B/0.75A   0.72°   20 Pin Rectangular
 RA16A-W   JH   F-101/F-107   PK566-B/0.75A   0.72°   20 Pin Rectangular
 RA16A-W-R   JH   F-101/F-107   PK566-B/0.75A   0.72°   20 Pin Rectangular
 RA16A-WH   GH-R   F-106/F-107   PK545-B/0.75A   0.72°   20 Pin Rectangular
 RA20A-W   JH   F-101/F-107   PK566-B/0.75A   0.72°   20 Pin Rectangular
 RA20A-W-R   JH   F-101/F-107   PK566-B/0.75A   0.72°   20 Pin Rectangular
 RA30A-W   JK   F-101/F-104   PK596-B/1.4A   0.72°   20 Pin Rectangular

* Yellow colored cell means different wiring type caused by mirror model.