Mark 5XL Technical Notes

Mark 5XL Technical Notes

mk53.jpg
latchset.jpg Cheater Pre-Load Adjustment
1. Allen wrench socket 2. 7/16 Hex Nut 3. Thread Friction Preload There must be slight friction on the cheater shaft thread, because the shaft moves with the motion of the index lever. The cheater knob should be slightly difficult to turn. If it drifts in use, indexing will be unreliable. The nylon tipped set screw, 3 in the above picture, acts as a brake on the threads and may be adjusted if needed. Cross shaft preload adjustment will probably never need to be done, as this preload is on ball bearings. It is easily accomplished with an allen wrench inserted into the socket (1) to immobilize the shaft, while the adjustment is made by turning the 7/16 Nylock hex nut (2). The critical test is with the latch fully engaged in an index gear tooth, when applying back and forth torque to the index gear, there should be NO detectable play or slop.
mk52.jpg Electronic Calibration
The units are shipped in calibration and tested at 0, 30, 45, 60, and 90. Due to internal construction details of the sensor, at true 0, the meter should read "00.04" to "00.17". Of course, no cutting should ever be done with the arm in the 0 position. Use your table adaptor! Units are locked permanently with a drilled-in-place dowel pin. Unless the unit has been subjected to very severe shock and vibration, there should never be any need to touch this adjustment! This is a sensitive adjustment. We store a calibration reference for each head that, under very rare circumstances, can be adjusted in the field.
mic1.jpg Micrometer Adjustment
The micrometer must not rotate as the head is swung in and out to inspect the stone, or the height adjustment might change. Adjustment of the micrometer head friction screw is simple. Unscrew the micrometer head to expose the adjusting nut. Depending on the micrometer, the adjustment nut may have notches or holes to engage the spanner wrench (supplied with the machine).
mic2.jpg
Tighten the nut a small amount, perhaps only 1/8 of a turn and screw in the micrometer head and see how you like the stiffness. Repeat as needed until the micrometer head requires a slight effort to rotate it.
Battery Note
If you begin to get erratic angle readings on your display your battery needs to be changed. The power draw of the circuitry is such that it requires a stable draw of milliamps as opposed to voltage. Fresh batteries are a must!