MicroBlaster MB1005
Section 4: Maintenance
Comco Inc.
4-5
Issue Date: September 2003
Parts Subject to Normal Wear
(cont’d)
Modulator
The modulator is an electro-mechanical device that is activated each time the footswitch
is depressed. The stop/start action of the modulator contributes to a consistent flow of
abrasive powder from the tank into the mixing chamber and out the nozzle. The
principles of operation are described in detail in Section 1 of this manual.
Due to its constant movement and its close proximity to the abrasive in the mixing
chamber, the mechanical part of the modulator, the modulator housing assembly, is
considered a wear point and should be inspected on a regular basis. The frequency,
with which the modulator should be inspected, depends on machine usage. Applications
that include heavy use, or very aggressive abrasives, may require checking the
modulator on a monthly basis. In light use, or mild abrasive applications, inspection
should be done every six months. It is recommended to replace the modulator housing
assembly every 2000 hours of operation, which is approximately one year of normal
operation. See Section 5 for inspection and repair procedures.
Pinch Tube and Plunger
The pinch tube and plunger are the parts of the pinch assembly that make contact with
the hose. Hoses can sometimes develop leaks at the point where they are pinched.
Leakage of abrasive at these points can cut into the pinch tube and plunger causing
sharp edges that damage hoses. Inspect the pinch tube and plunger for sharp edges
every time you replace a hose (see Figure 4-1). Abnormal hose breakage, always at the
pinch, is an indication of pinch tube or plunger failure. See Section 5 for replacement
procedures.
Figure 4-1: Pinch Tube and Plunger Inspection
