Theory of Operation, Grinding Stones

ASSEMBLY INSTRUCTIONS/OPERATIONS

Operation

THEORY OF OPERATION

The SFG10E SURFACE GRINDERS operate on the principle of various multi-accessory attachments being utilized at rotational speeds to make direct contact with a work surface. Various types of multi-accessory attachments are secured to a recess provided in the rotating, aluminum disc located on the bottom of the machine. The specific type of multi-accessory attachment utilized during the grinding process directly affects the type of material removed, the material removal rate and the resulting flatness and smoothness of the surface.

The grinding process is directly controlled by these conditions:

1)The use of a suitable mechanism (multi-accessory attachment) of proper design and configuration to grind the work surface and remove material while delivering acceptable service life.

2)Sufficient static weight supporting the multi- accessory attachment to allow it to effectively penetrate the work surface and remove material.

3)Adequate horsepower capable of propelling the multi- accessory attachment against the work surface to deliver acceptable productivity rates.

Since no two materials are exactly alike, no two work surface materials can be penetrated and removed by the exact same method. The nature of the grinding process, along with operator experience, skill and common sense, would suggest that efficient and productive material removal is a matter of trial and error. Combinations of multi-accessory attachment type, condition, and feed rate are direct factors that will also determine the overall success of the job application.

MULTI-ACCESSORY ATTACHMENTS AND APPLICATIONS

While individual multi-accessory attachment design and configuration may vary, basic operational characteristics are identical: impact upon a work surface material and remove a percentage of the material. This common operational characteristic has led to the development of the following popular multi-accessory attachments:

Grinding Stones

Grinding stones are available in a number of grades, including: C06 extra coarse, C10 coarse, C24 medium, C80 fine and C120 super fine grade. FIGURE 4. All stones incorporate silicon carbide as the abrasive medium and employ a clay binder as the matrix material. Vitrified type stones utilize an oven baking process that produces greater service life over other manufacturing processes. As the clay material wears away, it exposes new, sharp, edges of

the imbedded silicon carbide material. All stones have the identical 2" x 2" X 4" dimensions and are secured to the machine by the use of a plastic wedge.

FIGURE 4

The designation system for the grinding stones utilizes a system similarly utilized for most abrasive products: the larger the number, the finer the grain structure and usually, the smoother resulting finish.

a)The C06 and C10 coarse grade stones are the most popular utilized stones and result in maximum material removal rates.They are utilized for general grinding and the removal of trowel marks, high spots and rough sections on concrete surfaces.The average service life is approximately 4 to 10 hours.

b)The C24 medium grade stone will result in lower material removal rates. It is utilized for finer finish grinding of concrete and rough grinding on terrazzo and other types of stone floor configurations.The average service life is approximately 6 to 10 hours.

c)The C80 fine grade stone will result in still lower material removal rates. It is utilized for polishing concrete and medium grinding on terrazzo and other types of stone floor configurations with a water/slurry mixture only.The average service life is approximately 8 to 20 hours.

d)The C120 super fine grade stone will result in the lowest material removal rates. It is utilized for final polishing on terrazzo and other types of stone floor configurations with a water/slurry mixture only. The average service life is approximately 40 to 75 hours.

SFG10E ELECTRIC SURFACE GRINDER — OPERATION AND PARTS MANUAL — REV. #1 (07/16/07) — PAGE 13