horizontal Scaler

As the device with pendulum construction for measuring vertical inclinations were already shown previously, for the next, horizontal scaling device is introdued today. LASER beam equipped level device is utilized for the purpose of toe-in and thrust angle scaling and adjustment, two buble scales forming 90 degree direction each other are disassembled and constructed with establishing parallelism with the case standard surface on fine precisions. Importance is LASER beam direction, so spending half a day, it is precisely calibrated on 9600mm distance for the proof readings, also minimum iris closure to 1,2mm diameter beam were performed at the same distance.

Most important portion is the adaptations with wheel hub scaling point, ordinally appears if wheel center cap were removed. The touching dowel pins are so invested as to keeping width and avoiding touching on inner parts, hub locking nuts,etc. The accuracy on the tips of metal pins are established with hand filing method depending on 10/1000 mm accuracy digital micrometer device.

On actual scaling mission, the tips of pins are pressed on the suface of hub scaling point s, 3 o'clock and 9 o'clock positions with adequate pressure on special method, of course the parallelism of the device itself is checked so carefully adjusted relying on the bubble scales, they all are intended to obtain the scaling accuracy and datum repeatability.

Even 1,00 minute(angle value) toe-out in frontal axle caused strutting feel in centric steering position and relatively heavy reactions on EP82 TOYOTA Starlet, having anything to do with the previous set back correction . The movement on frontal hub position to backward must have affected the tie-rod end position changed into inside direction, leading to toe-out conditioned alignment, based on the construction that brake caliper is equipped anteriorly and tie-rod is so done posteriorly.

This adjustment today has completely wiped out the tendency to change running direction unintentionally, causing unexpected anxiety even while straight touring,leading to nervous driving fatigue. The phenomena caused by the principle of physical property appears clearly on smaller and lighter vehicle. So EP82 is the best experimental object on wheel alignment establishments.

The first description shows the number, not 1 but 1,00 has deeper meanings, it's a result of complicated calculations obtained by desperate efforts. For example, they are provisions of measurement conditions, vehicle was fixed on reference plane exactly parallel to the ground, tire pressur is so controled as not to be affected by spot deformetion while the measurements, vehicle was adequately moved anterior-posteriorly to open and release the internal stress of tires and arm hinge bushes. The datum obtained with repetitions were statistically analyzed in scientific manners.