Table of Contents
Service Instructions 878-M PREMIUM - 03.0 - 10/2019 1
1 About these instructions ......................................................... 5
1.1 For whom are these instructions intended?................................ 5
1.2 Representation conventions – symbols and characters ............. 5
1.3 Other documents ........................................................................ 7
1.4 Liability........................................................................................ 7
2 Safety.........................................................................................9
2.1 Basic safety instructions ............................................................. 9
2.2 Signal words and symbols used in warnings............................ 10
3 Working basis ......................................................................... 13
3.1 Order of the settings ................................................................. 13
3.2 Laying the cable guide.............................................................. 13
3.3 Machine operation lock............................................................. 14
3.4 Removing the covers................................................................ 15
3.4.1 Access to the underside of the machine................................... 15
3.4.2 Removing and placing the arm covers ..................................... 16
3.4.3 Removing and placing the head cover .....................................17
3.4.4 Removing and placing the valve cover..................................... 17
3.4.5 Disassembling and assembling the throat plate ....................... 18
3.4.6 Disassembling and assembling the circular feed dog...............19
3.5 Flats on shafts .......................................................................... 20
3.6 Locking the machine in place ................................................... 21
3.7 Setting the handwheel into position.......................................... 22
4 Setting the handwheel scale.................................................. 23
5 Positioning the arm shaft.......................................................24
6 Positioning the toothed belt wheels ..................................... 25
6.1 Positioning the upper toothed belt wheel.................................. 25
6.2 Positioning the lower toothed belt wheel .................................. 26
7 Setting the needle bar ............................................................ 27
7.1 Aligning the needle bar linkage sideways................................. 27
7.2 Angular position of the single-needle sewing machine needle
holder........................................................................................ 29
8 Setting the sewing foot .......................................................... 30
9 Needle guides in 2-needle machines.................................... 33
10 Setting the hook and the needle bar..................................... 34
10.1 Hook height............................................................................... 34
10.2 Setting the looping stroke ......................................................... 35
10.3 Setting the needle bar height.................................................... 37
10.4 Setting the side distance of the hook........................................ 38
10.5 Setting the needle guard........................................................... 39
10.6 Setting the loop former ............................................................. 40
11 Setting the opening of the middle part of the hook............. 41
11.1 Setting the lifting gap ................................................................ 42
11.2 Setting the timing for lifting ....................................................... 43