MK Products DiamondBack Weldhead - Manual (Page 14)

DiamondBack ™ Owner’s Manual - Page 6
Collets
A set of Collets is defined as 3 each 120° segments for each side of the
weldhead. Typically, 2 sets are required per each weldhead (See Appendix A
for Part Numbers.
Section D Maintenance
Due to the complexity of the DiamondBack™ ; there is no maintenance
permitted for the DiamondBack™ with the exception of preventive
maintenance, adjustments and replacement of consumables.
NOTE: Disassembly of weldhead will void the warranty.
Preventative Maintenance
Prior to performing any maintenance, the weldhead should be tested to
“benchmark” its performance. A normal calibration should be run and the
required correction noted. If the weldhead is running slowly or sluggishly,
this usually indicates that there is an excessive load on the drive motor, and
that maintenance is required.
Rotor Accuracy
Weld uniformity depends on the accuracy of the position of the rotor during
welding. Rotor rotation should be circular in motion in a plane at right angles
to the tube and concentric with the center of the tube to be welded. Any
deviation from the proper tracking or discontinuity in the rotor will appear in
the weld.
Problems in the plane of rotation are usually associated with Collets and can
be corrected by Collet modification. Discontinuities with rotor motion are
more serious and may require replacement of the rotor, the race, or both.
Proper replacement requires factory tooling and is not a field repair.
Cable Assembly
An electrical measurement should be made to determine continuity from the
positive cable connector to the rotor and from the negative cable connector
to the jaws on the weldhead.
Resistance measurements should be less than 0.1 ohms.
A measurement should also be made to verify that no conductivity exists
between the positive and negative power cables. Any measurable
conductivity through the weldhead will severely reduce arc start reliability.
The resistance measurement must be greater than 20 M
Ω
when measured
between the tungsten and the jaws.
A visual inspection should be made to determine the condition of the
weldhead and the cable assembly. If there are damaged or worn items, the
weldhead should be returned for factory service.