Hyd-Mech H-18 ASV, Manual

Page: 42 / 132

3.18 3.19
CALIBRATION PROCEDURE
Length calibration may be achieved in two ways, by inputting the ACTUAL LTH or LTH CONST parameter.
To determine the ACTUAL LTH value, the LTH CLB (length calibration) procedure must be executed.
In manual mode, position a piece of material, which is longer that the shuttle full stroke length and close the
front vise. Simultaneously press the “FWD” and “REV” buttons on the PLC to access the parameter. A pass-
word is required at this point, which can be obtained from the Hyd·Mech Service Dept. The screen will then
display as follows:
With the cursor at the shown position press the enter button. The cycle start button will the start to flash and
the “Enter” will change to “On” indication self calibration modes. Start the blade and the trim cut will be made.
After the trim cut is made the head will rise, the shuttle will retract fully in slow speed, clamp the material and
come fully forward in slow speed to the home position and make a cut. After the cut is complete “On” will
change back to “Press Enter”. Measure the length of the cut part.
Move the cursor down to the “ACTUAL LTH” and enter the length of the cut part. Then exit the parameters by
pressing the AUTO/MAN key (the cycle start button will stop flashing). To determine if the encoder channels
are connected correctly, observe the actual length parameter for the sign only during shuttle retraction in cali-
bration mode. If the actual length value shows as a negative number, then the channels must be reversed and
the calibration procedure repeated.
To determine “LTH CONST” value, use this formula;
LTH CONST = ENCODER PINION CIRCUMFERENCE (TTd) ÷ ENCODER RESOLUTION
Example:
For a 1” pinion diameter and 2500 PPR encoder:
LTH CONST = TTD ÷ 2500PPR = 0.001257
NOTE:
When first entering the parameters screen if not running the self-calibration do not use the enter key but use
the cursor keys to scroll through the parameters.
To check length control consistency:
1. Perform test cuts of three different lengths (i.e. 1”, 12”, 20”) and measure as accurately as possible with
a Vernier or dial caliper.
2. If the measurements indicate a linear problem (measured length error increases as the programmed
length increases), the “ACTUAL LGTH” or “LTH CONST” value will have to be adjusted.
To adjust “ACTUAL LGTH” value The Length Calibration Procedure MUST be performed. This may be done
with material in the machine (cut and measure material length) or with no material in the machine (let machine
complete the calibration cycle, then enter new value).
If part length error gets longer as the programmed length increases; ACTUAL LTH value should be increased.
If part length error gets shorter as the programmed length increases; ACTUAL LTH value should be decreased.
Make small adjustments at a time (i.e. .020” - .030”) and check with test cuts.