Brother LH4-B800E Service Manual download pdf (Page 117)

LH4-B800E

5 - 2

5. Troubleshooting guide

Cause Check Solution page

Thread take-

up spring

Thread take-up spring

tension and stroke

Adjust thread take-up

spring tension and

stroke

tension stroke

Loosen the tension or shorten the

stroke to such a degree that does

not cause double hooking

Adjust it while checking bar tacking

stitches

-

(Instruction)

Rotary hook Needle height when

rotary hook point

aligned with needle

center

(Needle bar height and

needle bar rise)

Adjust its timing

Three kinds of gauges

are available

For -2, for -3 and for -5

Adjust the needle bar height to "1"

on the gauge

Adjust needle bar height to "2" on

the gauge

4-6

Gap between needle

and rotary hook

Adjust the gap Widen the gap (0.01 - 0.08 mm) to

such a degree that rotary hook point

does not strike needle in zigzag

motion

4-6

Rotary hook lubrication Adjust the quantity of

lubrication oil

Too small quantity of lubrication oil

will cause thread breakage

* Check the quantity of lubrication

as follows; When the number of

stitches is about 114, sew 20

stitches and using craft paper,

check that the number of splashed

oil spots is about 10

4-27

Thread twisted around

rotary hook

Remove any twisted

thread from the inner

and outer rotary hook.

-

Needle

thread take

up

Arm thread guide

position

Adjust arm thread

guide position

Adjust the center of screw to the

carved mark

-

Bobbin case Damaged outside of

bobbin case

Bent bobbin holder

spring, etc.

Polish with buff

Replace the part

Use the B800E bobbin case. -

Gauge

W(0.1 - 0.2 N)

4 - 6 mm

2.5 mm(-2, -5)

3.5 mm(-3)

0.01 - 0.08 mm

Carved mark

Gap 0.5 mm

1 2 ... 112 113 114 115 116 117 118 119 120 121 122 ... 167 168

Comments to this Manuals

No comments