AUTOFEED-MIN-LIMIT This parameter works with the AUTOFEED feature. It specifies the minimum allowable feed rate override percentage that the AUTOFEED feature can use and should initially be set to 1.Lead Screw CompensationSeparate lead screw compensation is provided for each of the X, Y, and Zaxes. The operator-entered compensation values are spaced at 0.5 inch intervals within the machine coordinate system The compensation values are entered in inches with a resolution of 0.0001 inch. the operator entered values are used to interpolate into a table of 256 entries. The spacing between two entries in the table of 256 is defined by Parameter 58. the entered values are limited to +/- 127 encoder steps; so the limit in inches is dependent on Parameter 5,19 and 33.Note that the first entry corresponds to machine position zero and subsequent entries are for increasingly negative positions in the machine coordinate system. The user should not ever need to adjust the lead screw compensation tables.Electronic Thermal CompensationWhen ball screws rotate they generate heat. Heat causes the ball screws to expand. In constant duty cycles as in mold making the resultant ball screw growth can lead to cutting errors on the next morning start up. Haas’s new ECT algorithm can accurately model this heating and cooking effect and electronically expand and contract the screw to give near glass scale accuracy and consistency.This compensation is based on a model of the lead screw which calculates heating based on the distance traveled and the torque applied to the motor. This compensation does not correct the thermal growth due to changes in ambient temperature or due to part expansion.Electronic thermal compensation works by estimating the heating of the screw based on the total amount of torque applied to the screw. The heat is then turned into a thermal coefficient of expansion and the position of the axis is multiplied by the coefficient to get a correction amount.The compensation time constant is on the order of 20 to 50 minutes to lose half of the heat in the screw. If the machine is turned off when there is some compensation applied (due to motion and heating of the screw), when the machine is turned back on, the compensation will be adjusted by the clock indicated elapsed time. Thus a real time clock is required for this compensation to work if the machine is turned off for less than 2 hours.