Brenell MINI 8 - Page 18

18 pages

Save Page as PDF

To Previous Page

To Previous Page

Loading...

Appendix

C

Mini

8

Logic

Pinch

Solenoid

-

’

Lock

On

’

Adjustment

Single

Solenoid

Type

The

purpose

of

this

adjustment

is

to

ensure

that

the

pinch

solenoid

plunger

’

Locks

On

’

to

achieve

correct

pressure

between

pinch

wheel

and

capstan

shaft,

thus

obtaining

constant

tape

driving

speed.

This

adjustment

will

only

affect

the

pinch

plunger

locking

position,

it

will

not

alter

the

final

pinch

operating

pressure.

Adjustment

Procedure

1.

Remove

left

hand

wooden

side

panel

2.

Remove

back

panel

and

disconnect

fan

leads

3.

Ensure

that

pinch

wheel

carrier

(diag:

DI

SH-2)

is

correctly

located

on

its

drive

pin.

That

is,

make

sure

that

the

two

’

Allen

Screws

’

are

tightened

on

to

the

’

Flat

’

of

the

drive

pin

squarely.

4.

Go

to

rear

of

machine

and

push

pinch

solenoid

plunger

(Diag:

G

SH-1)

slowly

into

the

solenoid,

until

the

pinch

wheel

touches

the

capstan

shaft.

The

plunger,

if

adjustment

is

correct,

should

not

yet

have

reached

the

end

of

its

travel

by

approximately

1.5

mm.

The

last

1.5

mm.

of

plunger

travel

is

the

amount

of

movement

required

to

tension

the

pinch

pressure

spring

prior

to

’

Lock

On

’

of

the

plunger.

(Hereafter

referred

to

as

’

Spring

Tension

Travel

’

)

If

the

’

Spring

Tension

Travel

’

of

the

plunger

exceeds

1.5

mm,

it

will

not

achieve

’

Lock

On'

and

therefore

the

final

pinch

pressure

will

be

’

Low'

causing

tape

'Slip'

and

erratic

tape

path.

5.

If

'Spring

Tension

Travel'

is

excessive

(i.e.

if

pinch

operates

but

plunger

does

not

'Lock

On')

adjust

as

follows:-

5a.

Loosen

2BA

locknut

on

plunger

5b.

Turn

plunger

'Clockwise'

(screw

into

solenoid)

half

a

turn,

and

tighten

lock

nut.

Test

Procedure

After

Adjustment

Insulate

mains

leads

to

fan

Switch

on

machine

Hold

pinch

carrier

in

'Off'

position

firmly

by

hand

Push

'Play'

button

(still

holding

carrier

firmly)

and

slowly

allow

the

pinch

wheel

to

move

towards

the

capstan

shaft.

If

correct

adjustment

has

been

achieved,

'Lock

On'

will

be

heard

as

the

pinch

wheel

contacts

with

the

capstan

shaft.

If

'Lock

On'

is

not

achieved,

then

repeat

adjustment

as

in

5a

and

5b

a

half

turn

at

a

time

until

correct.

Finally,

thread

tape

onto

the

machine

and

select

fast

forward

mode.

Check

that

pinch

wheel

just

clears

the

tape

(see

Diag:

SH-2)

if

tape

touches

pinch

wheel,

then

adjust

'Buffer

Bracket'

(Diag:

SH-1)