Figure 46. Geometry of individual chisel teeth

For finish grading, we used a different chisel-

There may be many days when weather con-

tooth design for the blade (Fig. 45) than was used

ditions reduce surface visibility to near zero

for initial grading. This blade appeared more ag-

due to diffuse light or blowing snow.

gressive than the one used for the first passes and

We found that the laser system was able to

was designed with an alternating tall- and short-

function and produce accurate grade even when

tooth pattern to assist in cleaning the surface of

the grader operator had great difficulty seeing

all debris. The geometry of the cutting teeth was

well enough to drive in a straight line. However,

similar to the rough grade blade with an included

angle of 42 and side relief angles of 41 (Fig. 46).

we found that the standard laser system trans-

mitter tower was not robust enough and began

However, the cutting teeth were considerably

vibrating under moderate wind conditions. This

longer, at 9.6 cm (3.8 in). The cleaning teeth had

an internal angle of 60, a height of 5.7 cm (2.2

caused the emitted laser plane to shift rapidly

and with such amplitude as to cause the grader

in.), and no side relief cut-out. The lower edge of

blade to go into convulsions. Thus, we constructed

the cutting teeth was flared to a width of 5.7 cm

a sturdy tower, mounted on skis for efficient

(2.2 in.) and was 4 cm (1.6 in.) closer to the ice

repositioning, on which to place the transmitter

than the cleaning teeth. For most of the runway,

(Fig. 44).

only one pass was required to arrive at the de-

19.1

A

B

97

(ref)

41.3

97

(ref)

193.7

97

57.2

C

B

C

L

C

L

101.6

A

(typ)

57.2

(ref)

57.2

60.3

(typ)

19.1

41

7.9

16.7

14.3

38

97

All Dimensions are in millimeters

57.2

(typ)

Figure 46. Geometry of individual chisel teeth.

43