MODULAR RACK & PINION SYSTEM - Andantex USA Inc.

MODULAR RACK & PINION SYSTEM
Once the desired tolerance is reached, attach the rack to the machine frame using Class
12.9 socket head capscrews tightened to the torque values shown in the table below:
Screw Size M6 M8 M12 M16 M20 M30
Tightening
Torque 10 (7) 26 (19) 89 (66) 215 (159) 420 (310) 1450 (1070)
NM (LB. Ft.)
4. Attach the next rack segment to the
rack mounting surface. A companion
rack should be used to properly
space the teeth in-between rack
segments.
Again measure the location from the
rail in relation to the rack segment
(as in step #3). Continue mounting the
rack segments for the entire travel
length using the same procedure.
5. Mount the pinion/gearbox to the rail
carriage. Make sure the pinion
engages the total face width of the
rack. Check the alignment of the
rack & pinion by marking or “bluing”
the pinion teeth with a high spot
paste (Dykem) and slowly running
the axis in both directions. This will
show the tooth contact pattern
between the rack & pinion; a
contact pattern across the majority
of the tooth flank on both the rack
and pinion is desired. If the contact
pattern is shifted to one side of
the tooth flanks, some form of
misalignment is present.
Pinion not perpendicular
Pinion not parallel
6. Measure the linear backlash between
the rack & pinion along the entire
axis travel length. A general guide for
minimum backlash is shown below:
Rack Quality
Minimum Backlash
Induction Hardened 0.20 mm (0.008”)
Quenched & Tempered 0.10 mm (0.004”)
Hardened & Ground 0.05 mm (0.002”)
7. Run the pinion/gearbox through the
entire rack travel length to check
for any problems, such as binding
or excessive noise. If either is
found, return to step #3.
8. Drill dowel pin holes into the rack
mounting surface using the pilot
holes in racks. Place dowel pins
in the holes (two for each rack
segment).
Correct Mesh
Pinion not perpendicular
Pinion not parallel
Incorrect center distance
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