Festo EXCM-10, Repair Instructions

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30 / 52 Festo 7EXCMc_en
– Visible individual glass fibre cords in the tooth gullet are secondary signs of wear due to primary wear of the nylon
fabric. In this case, the toothed belt pulley assembly must be examined very carefully for wear, as visible glass fibre
cords may have caused severe abrasive damage to the sides of the tooth tip of the toothed belt pulleys.
If the toothed belt suffers premature failure, the operating conditions should be observed more closely.
The following possibilities should be considered, among other things:
– Overloading
Incorrect set values of the braking ramp in STOP status (e.g. EMERGENCY STOP, quick stop) result in overloading of
the planar surface gantry and can irreparably damage it or reduce its life drastically.
The elasticity of the toothed belt delays the acceleration and braking performance of the planar surface gantry and
results in greater acceleration and deceleration than set at the controller (spring effect).
Block-shaped acceleration and deceleration profiles (no jerk limitation) cause high peaks in the drive force that
can lead to overloading of the drive. Positions outside of the permissible range can also occur. An acceleration and
deceleration specification with jerk limitation reduces oscillations in the entire system and has a positive effect on
the stresses to which the mechanical system is subjected.
–
Check which controller settings can be adjusted (e.g. jerk limitation, smoothing of the acceleration profile).
– Check the settings for all braking ramps in your controller or the higher-order control system (deceleration values
and jerk).
– Make sure that the deceleration values (braking deceleration, deceleration times) for the speed, the load to be
moved and the installation position (horizontal / vertical) and the specified maximum drive torque or the feed
force correspond to the allowable values of the planar surface gantry used.
– Use the Festo “PositioningDrives” design software, available via the Festo website (

www.festo.com ), to design
the planar surface gantry.
– Ambient conditions/material resistance
– Check whether the ambient temperature is within the permissible range.
– Check the chemical and physical ambient conditions for hazardous substances, such as dust, abrasive particles,
cooling lubricants, solvents, ozone, radiation, water-soluble substances, greases and oils, etc.
4.1.4.4 Installing the toothed belt
Cutting the new toothed belt to length
The exact length of the toothed belt in mm is derived from the total of the zero stroke plus 4 × X stroke plus 2 × Y stroke.
Check the length of the new toothed belt and shorten it, if necessary, to the calculated length with sturdy general
purpose scissors. See order example:
Toothed belt length = Zero stroke ((4 × X stroke) + (2 × Y stroke))
 
Example: EXCM-10-300-210-GF-ST-B-E1
Zero stroke length: 490 mm
X-stroke: 300 mm
Y-stroke: 210 mm
Length of the toothed belt = 2110 mm
Note
Always cut the toothed belt to length between two teeth.