The Norden Bomb Sight manual

CAUTION

Speed

of Sta-

bilizer

Gyro

Replace-

ment of

Carbon

Brushes,

Stab.

Fig.

24

Keep using a

new section of the cloth

until clotn

comes out clean after being in contact with

the

commutator,

Scrape between

segments

(away from

terminal with wedge-pointed orange

stick.

Never

use metal stick of any

kind

for holding

cloth on

commutator.

d.

Use very

small amount of alcohol or carbon

tet.

for cleaning brushes and brush tubes.

Do not

use benzine.

If the commutator is

rough or grooved,

gyro should be disassembled.

Use #400 aluminum

oxide paper to remove roughness and grooves.

must be taken or the commutator may be

tapered

or hollowed.

Always check to make sure

commutator is not out of round.

If it is tapered

or hollow

in spots, the

commutator must be turned

down on a

lathe; otherwise the gyro would be out

of balance and

the low spots would cause arcing

pitting of the commutator.

Never use an

abrasive on the commutator while

it is installed

in the

gyro case.

serious damage to do const conautt0%a

Some of the

will be deposited on the bearings and

serious damage to the bearings will result.

-When

an abrasive is used on a

commutator, the commutator

should be rotating on

its own

bearings or in a

lathe.

After an abrasive has been used oh the

commutator,

always remove the burrs between the

segments with #400 aluminum oxide paper and clean

with a white cloth moistened with carbon-tet.

carbon-tet,

used the

commutator must be clean-

ed with a

clean, dry cloth to remove crystaline

residue.

f.

If the commutator is pitted it should be

turned down in a

lathe on its

own bearings by an

experienced machinest.

{This

is a depot or fac-

tory job.) If the commutator is worn,

bilizer,

so that correct

gyre speed cannot be ob-

tained,

or if proper precession is impossible,

report the trouble and await disposition.

. The

stabilizer gyro turns

approximately

8000 plus or minus 400 r. p.m. when operating

13.5 volts.

Carbon brushes will be replaced when

14 is

worn

from

their length

las compared to a new one.)

Installation of new carbon brushes.

plug on

pigtal!

for fit in tube. Place spriot

fold back 112* of

pigtail,

refoid

leaving lead to

brush coming out

that in half folds, then clamp