Fagor CNC 8055i FL EN - Page 422

·422·
Installation manual
CNC 8055
CNC 8055i
7.
CONCEPTS
SOFT: V02.2X
Compensation of the elastic deformation in the coupling of an axis
Sample
To adjust the compensation of elastic deformation caused in the X axis of a laser cutting machine.
The machine has two servomotors with position feedback that move the tool tip in a plane defined
by the X and Y axes. Supposing that only the X axis has an elastic coupling.
Its purpose is to drill circular holes with a radius R = 5 mm = 0.005 m at high speed on a sheet metal
that rests on fixed frame.
To obtain the frequency value for setting axis parameter DYNDEFRQ (P103) to compensate the
elastic compensation on the X axis, proceed as follows.
1. Make a hole keeping the tool tip at high feedrate, for example, F = 8000 mm/min in order to cause
high deviation x and generate a clear elliptical path.
2. Once the hole has been made, use a caliper to measure the various diameters of the elliptical
hole until obtaining the diameter of the larger axis Dm of the ellipse. Observe that the elliptical
shape will not be visually noticeable.
The real shape is elliptical, not circular, when only the X axis suffers elastic deformation.
3. Obtain the value of the elastic deformation from the formula:
Let us suppose (for the sake of using numbers) that the deformation value is: x = 90 µm = 90
x 10
-6
m.
4. Obtain the acceleration value for a circular path from the formula:
5. Obtain the frequency value from the formula:
6. Set machine axis parameter DYNDEFRQ (P103) with the obtained value, i.e. DYNDEFRQ
(P103) = 31.8 Hz.
7. Verify that after setting axis parameter DYNDEFRQ (P103), your particular part is machined
properly regardless of the path of its profile.
x
D
m
2
-------
R–=
a
F 60
2
R
---------------------
860
2
0 005
--------------------
36ms
2
===
f
1
2
------
a
x
------
1
2
------
36
90 10
6–

----------------------- 31 8Hz== =