Xt = Xp + RsinBcosA, Yt = Yp + RcosBsinA, Zt = Zp + RcosAcosB, Where R is the distance between center of
rotation and the tool tip. V.
Calibrate A-axis
angular accuracy Mount the laser head at position 3 as shown in Fig. 2.
Starting position is
at Yp = Zp = A = B = 0, Move A-axis with 5 degrees increment
while keeping the tool tip position
fixed.
That is,Yp = -RsinA Zp = -R(1- cosA), where A =
0°,5°,10°…..90°.
Hence, dA
= -dYp/(RcosA), where dA is the angular error at A degrees and
dYp is the measured deviation at A
degrees. A
sample parts program is shown in Table
1. The measured deviations in
x-direction
are shown in fig. 3 and the calculated angular errors are shown in Fig. 4..
Table
1, A sample parts program moving along a circle and keep
the tool tip at a fixed position by rotating A-axis.
5AXIS
SAMPLE PPM (5-axis,R=15",5-degree linear
interpolation) (up to 90 degrees)
G0 Y0.Z0. G91 G01 G93 F2. M00
Y-1.3073Z-0.0571A5. Y-1.2974Z-0.1708A5. Y-1.2776Z-0.2832A5. Y-1.2480Z-0.3935A5. Y-1.2090Z-0.5008A5. Y-1.1607Z-0.6042A5. Y-1.1036Z-0.7031A5. Y-1.0382Z-0.7966A5. Y-0.9648Z-0.8841A5.
Y-0.8841Z-0.9648A5. Y-0.7966Z-1.0382A5. Y-0.7031Z-1.1036A5. Y-0.6042Z-1.1607A5. Y-0.5008Z-1.2090A5. Y-0.3935Z-1.2480A5. Y-0.2832Z-1.2776A5. Y-0.1708Z-1.2974A5. Y-0.0571Z-1.3073A5. M30
% Fig. 4, Angular errors of the rotational-axis.
Fig.
3, Measured deviations in Y-direction
due to the angular
errors Angular
errors-0.06-0.04-0.0200.020.040
20
40
60
80A,
degreesDeviation in
Y-0.02-0.0100.010.020.03A,
degreesClick here to down
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