Issue link: https://docs.hic.us/i/445658
215 Chapter 11 Troubleshooting (2) Case to be conducted by the distributor Thread breakage Density of design data does not match with material and/or thread. Correct data. Bad frame attaching and fixing of the fabric Attach the frame correctly. Fix the fabric firmly. Thread, needle and/or size of needle plate do not match with embroidery. Make combination that fits to design data/material. R.P.M. is too high. Decrease R.P.M. Frame drive timing does not fit to embroidery condition. Change setting.(→p.170) The following works should be performed by technical personnel of the distributor. Customer should not cope with these works. Cause Corrective Action Scratch, abrasion of rotary hook Grind a scratch with sandpaper etc. Replace. A clearance between needle and hook point of rotary hook is not suitable. Perform adjustment so that a clearance becomes 0.1 to 0.3 mm. A clearance between rotary hook and rotary hook support is narrow. Adjust a clearance to about 0.5 mm. Timing between needle and rotary hook is too early or too late. Adjust the main shaft angle between 211.5 to 217° (Standard value is 213°) Bad adjustment of lower dead point and/or upper dead point of needle bar Adjust to the standard value using the lower dead point gauge. The play of rotary hook shaft is big in back and forth direction. Adjust the play. There is a play on the fringe of frame. Adjust the play. Replace the part. Rotation of the main shaft is not smooth. Perform alignment of the shaft. Abrasion/breakage of neighboring parts of take- up lever drive and/or needle bar drive Replace the part. Play of needle bar case (in right and left direction) is big. Adjust. Bad take-up lever timing Adjust start-up timing. Tension of upper/lower shaft connecting belt is weak. Adjust. Main shaft timing belt is loose. Adjust. Set screw of the main shaft timing pulley is loose. Tighten again. Cause Corrective Action CAUTION ! QS04