Understanding Swivel Stage (Goniometer)

Understanding Specifications

SA07A-RT02

Specifications			Description
Model Number		SA07A-RT02	1. Kohzu's significant alpha-numeric model numbers offer quick product insight.
Mirror Model Number		SA07A-RT02-R	2. Mirror symmetry of standard stage.
Table Size		70mm×70mm	3. Table size refers to the stage's valid mounting table size.
Guide Mechanism		Cross-Roller Guide	4. Type of guide mechanism used on this stage.
Angular Range		±10°	5. Stage travel range in the positive and negative directions from it's centered or neutral position.
Lead Mechanism		Worm & Worm Wheel	6. Feeding Mechanism and feed screw pitch.
Resolution	Full/Half Step	0.00153°/0.000765°	7. Variation of the stage resolution which is defined by microstep division.
	Micro Step (1/20 div)	0.0000765°
Maximum Speed		7.65°/sec	8. Maximum Speed of standard stage (half step, 10kpps).
Work Distance		70mm±0.2mm	9. Distance from table surface to rotation center.
Rotation Center Play		Φ0.05mm/±10°	10. Difference of rotation center while stage is rotating.
Lost Motion		≦0.003°	11. Refer the "Inspection System"
Backlash		≦0.001°	12. Refer the "Inspection System"
Moment Load Stiffness		0.09 arcsec/N・cm	13. Moment load stiffness is measured in a direction perpendicular to the motion axis.
Load Capacity (Horizontal)		49N(5kgf)	14. Maximum load capacity is for a horizontally orientated stage with load centered on top-plate.
Material		Aluminum Alloy	15. Material specification is for stage's main body components only.
Finish		Clear-Matte Anodizing	16. Surface finish type and color.
Weight		0.95kg	17. Stage weight includes all components depicted in product photograph.
Perpendicularity		−	18. Perpendicularity (or orthogonality) between motion axes in a dual-axis XY direction assembly.
Standard Motor		Five (5) phase stepper motor (Oriental Motor: PK544PMB) Phase Current 0.75A, Basic Step Angle 0.36°	19. Actuator type of standard stage.
Standard Connector		20Pin Round (Hirose: RP13A-12RA-20PC)	20. Connector type of standard stage.
Stage Wiring Type		V3	21. Wiring type is connection between stage and stepper motor, and photo-sensor.
Price(JPY)		¥149,000	22. Catalog price in Japanese currency.
Overhaul Price *		¥36,000 〜	23. overhaul price in Japanese currency
Clean Room Lubricant Change Price		¥24,000	24. Clean Room Lubricant change Price in Japanese currency.
Vacuum Lubricant Change Price		¥24,000	25. Vacuum Lubricant change Price in Japanese currency.
Same Size Motor Change Price		¥12,000 〜	26. Change price of same size motor's mounting as standard motor's in Japanese currency.
Different Size Motor Change Price		¥30,000 〜	27. 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

●Cross-Roller Guide

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 (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 loadbearing surfaces, higher preloads and meet very tight run out and stiffness specifications.

Feeding Mechanism

●Worm Shaft and Worm Wheel

It allows to produce strong power or torque with the worm and worm wheel mechanism. As a result, it is decelerated but it can move precisely even when it has a big load.

●Ball Screw

The ball screw consists of a screw spindle, a nut, and steel ball between them (Fig. 3). When the screw is rotated, the ball rolls and moves between the ball screw and the nut, and then returns to its original position. Since a ball is rolled, the friction is low, a high transmission efficiency is obtained, the difference between static friction and dynamic friction is small, and stick-slip does not easily occur.

Feature of Ball Screw

●High Durability
Ball Screw is superior in terms of durability.
●Downsizing and Weight Saving
Ball Screw is high transmission efficiency of driving, then downsizing is substantialized by using the small size motor.

< Notification of Ball-screw Swivel Stage Mounting >
Mounting hole will not be appeared by driving of motor controller, because the controller detect the limit sensor. Then move the stage's table until appear the mounting hole for the screw by manual. In addition, when you drive the stage, set back around the home position and turn on the power.

Angular Motion

●Worm & Worm Wheel

Gradient angle adjustment of swivel stages are derived by motor rotation connected with worm wheel.

Δθs =　 Δθ / n・m

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

Model Number	Reduction ratio(n)	Basic step angle of motor (°/pulse)
SA04B-RT02	268	0.36
SA04B-RM02	364	0.36
SA05B-RT02	232	0.36
SA05B-RM02	300	0.36
SA05B-RB02	372	0.36
SA07A-RT02	235	0.36
SA07A-RM02	300	0.36
SA07A-RB02	375	0.36
SA10A-RT01	320	0.72
SA10A-RM01	428	0.72
SA10A-RB01	536	0.72
SA13A-RT01	288	0.72
SA13A-RM01	400	0.72
SA16A-RT01	510	0.72
SA16A-RM01	600	0.72

Maximum Speed

Maximum speed depends on individual motor torque characteristics. However, we calculate maximum speed at 10kpps with motor in half-step mode. Except of 10kpps, the value is fill in each specification.

●Ball Screw

Transform from the linear motion to revolution motion, then minimum resolution is different by stage's position. Then, if pulse signal is sent by constant speed, driving speed is not constant.

・ Ideal Resolution
　Δθs = sin^-1　( Δθ･P　/ 360･R･m )

・ Input Pulse
　ｐ = 360･m･R･Sin(θ) / Δθ･P

　Δθs: Ideal resolution(°)
　Δθ : Basic step angle of motor(°)
　P　: Pitch of ball screw(mm)
　R　: Distance between the fulcrum(mm)
　m　: Division number of micro step
　p　: Input pulse
　θ　: Angularmotion(°)

　Note: Angular motion is calculated from origin point(0°).

Model Number	Δθ	P	R
SA05A-R2T01	0.72	1	53.9
SA05A-R2M01	0.72	1	71.9
SA05A-R2B01	0.72	1	89.9
SA05A-R2G01	0.72	1	107.9
SA07A-R2T01	0.36	1	75.75
SA07A-R2M01	0.36	1	101.75
SA07A-R2B01	0.36	1	127.75
SA10A-R2T01	0.36	1	101.375
SA10A-R2M01	0.36	1	139.375
SA10A-R2B01	0.36	1	177.375

Standard & Reverse Stage Assembly Configurations

Upon request, we can supply reverse arrangement specifications in which the connector and the sensor are mounted in reverse horizontally. We can also provide a combination stage of a standard and reverse arrangement.