MK Products MiniMicro Orbital Weldhead User Manual

Page 16

Mini Micro

Owner’s Manual - Page 10

Extension Cable

When longer weldhead cables are needed, a weldhead extension cable

is also available in a 25’ length. The extension cable (P/N 005-0635) has

all the necessary connections needed to connect the MiniMicro™ to the

CobraTig

150: welding leads, gas, coolant supply and return and control

interface, or to an ACL using the Pig Tail Kit (P/N 005-0619).

Collets

A set of Collets is defi ned 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 MiniMicro™; there is no maintenance

permitted for the MiniMicro™ with the exception of preventive maintenance,

adjustments and replacement of consumables.

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, this usually

If the weldhead is running slowly, 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 modifi cation. 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 fi eld 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.

Section

C Cont.