FEC AFC1200 - Manual (Page 3)

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w Two-step fastening
P After presetting the fastening sequence (Section 7.5 SET SEQUENCE) to perform
a two-step fastening, the System fastening parameters (Section 7.1 PARAMETER
SET) must be configured according to the engineered fastening specification.
P Two-step fastening will be used primarily for joints that have a requirement to
synchronize with another spindle during the final stage of the rundown (connecting
rods, main bearing caps, or any other multi-spindle application).
P The System will fasten to the 1ST TORQUE value during the specified 1ST STEP
time. Once either SPEED CHANGE TORQUE or 1ST TORQUE is reached, the
System will switch to the specified TORQUE SPEED (Section 6.3). When all
fasteners have reached 1ST TORQUE, the spindles will synchronize and fasten
simultaneously to STD during FINAL STEP time.
STD.
TORQUE
1ST STEP
FINAL
STEP
ANGLE
SPEED CHANGE
1st TORQUE
FIG. 6-1-1b Torque Control Functions for Two-Step Fastening
Maximum allowable Final Step cycle time FINAL STEP (TIME)
Maximum allowable 1st Step cycle time 1ST STEP (TIME)
30 ~ 50% of STD for Hard joints
50 ~ 90% of STD for Soft joints SPEED CHANGE (TORQUE)
30 ~ 50% of STD for Hard joints
50 ~ 90% of STD for Soft joints 1ST TORQUE
Engineered fastening specification STD (TORQUE)
RECOMMENDATION FUNCTION
w Three-Step Fastening
Chapter 6: Fastening Instructions
Page 6-3