Sewing and Fabric

Question 1

What is a salvage edge?

Answer 1

An edge that has been woven to prevent fraying.

Question 2

What is a raw edge?

Answer 2

An edge where the material has been cut.

Question 3

What are filling threads?

Answer 3

Threads that run perpendicular to the salvage edge.

Question 4

What is a bias?

Answer 4

A cut, fold, or seam at a 45 degree angle to the salvage edge.

Question 5

What is meant by the weight of cloth or fabric?

Answer 5

Calculated oz per sqr. yrd.

Question 6

List three factors that determine the characteristics of cloth.

Answer 6

Tightness of yarn twist, number of threads per inch, and type of weave used?

Question 7

Give four examples of synthetic fabrics.

Answer 7

Nylon, nylon duck, nomex, Naugahyde, and vinyl.

Question 8

Which is heavier webbing or tapes? What is the weight factor for that determination.

Answer 8

Webbing. Over 15 oz per sqr yd. and width of 12 in.

Question 9

List three characteristics of synthetics that make it not require any special storage consideration.

Answer 9

Absorbs little water, dries quick, mildew proof, not affected by most cleaning fluids, moth proof, not food supply, but larvae may eat their way out.

Question 10

List six conditions that are ideal for storing textiles.

Answer 10

A dry room at 70 F
No direct sunlight
Protection from insects and rodents
Smooth wooden shelves
Humidity and temp control
No smoking

Question 11

How should you route the thread around the bobbin when winding a bobbin?

Answer 11

The tread should pull from the bottom of the tension disks to the bottom of the bobbin.

Question 12

After you fill the bobbin what three threading points do you route the thread through when installing the bobbin in the case?

Answer 12

Into the slot on the case, then under the tension spring and into the delivery eye.

Question 13

Briefly describe how to route the needle thread around the tension and thread controller assemblies.

Answer 13

Form the letter S with the thread and put the top half around the tensions assembly and the bottom half around the tread controller assembly.

Question 14

In which direction do you route the thread through the thread take up lever.

Answer 14

First through the hole in the take up level and the various threading eyelets from right to left and then left to right through the eye of the needle.

Question 15

What precautions must you take to avoid damaging the teeth of the feed dog?

Answer 15

Don’t operate the machine without material or wind the bobbin with the pressure feet down.

Question 16

List 3 things involved in preventative maintenance.

Answer 16

Inspecting, cleaning, and lubing.

Question 17

List 3 things that can be used to clean a sewing machine.

Answer 17

Lint free cloth, soft bristle brush, and dry cleaning solvent.

Question 18

What do you use to lube the machine?

Answer 18

Light lubricating oil and ball bearing grease for some motors.

Question 19

What are the intervals for lubing the machine head?

Answer 19

2X each day or every 4 hrs of use.

Question 20

How do you install a new needle?

Answer 20

Fully insert the needle bar making the long groove face left.

Question 21

What should you do if the machine is breaking the needle thread and you discover the thread snaps are brittle?

Answer 21

Replace defective thread.

Question 22

What do you check if machine is skipping stitches?

Answer 22

Make sure its threaded properly, that the correct needle is installed, the needle eye is parallel with arm of machine and groove faces left and the needle bar is correctly set.

Question 23

What is the probable cause if you machine will not feed material through the machine but makes all the stitches in one spot?

Answer 23

Stitch regulator may be set at 0 stitches per inch and the feed dog does not move forward.

Question 24

What removes thread from the spool to make each stitch?

Answer 24

Thread take up lever.

Question 25

What removes tension from the needle thread when the presser bar is raised?

Answer 25

Tension release washer.

Question 26

What carries the needle to the stitch forming mechanism?

Answer 26

Needle bar.

Question 27

What is in the bed of the machine and the stitch forming mechanism?

Answer 27

Sewing hook.

Question 28

What attaches tho the drive belt which turns the arm shaft?

Answer 28

Balance wheel.

Question 29

What removes slack from the thread as the needle descends?

Answer 29

Thread controller spring.

Question 30

What parts form the stitch?

Answer 30

Sewing hook

Question 31

What parts reengages the safety clutch?

Answer 31

Push button

Question 32

What changes the SPI?

Answer 32

Stitch regulator lever.

Question 33

What component surrounds the feed dog and provides a smooth surface for material to be fed through the machine?

Answer 33

Throat (needle) plate

Question 34

What type of stitch forming mechanism does the 199-2A sewing machine have?

Answer 34

A transversely mounted sewing hook.

Question 35

Which different types of materials is the 199-2A designed to sew?

Answer 35

Upholstery, tarps, tents, parachutes and protective covers for aircraft.

Question 36

What 199-2A SPI range?

Answer 36

Appx. 5-32

Question 37

What is the difference between the needles on the 199-2A and the 767?

Answer 37

767 uses rotary hook so there must be a scarf, the 199-2A uses an oscillation hook and uses a short groove instead of a scarf.

Question 38

What type of feed does the 767 have?

Answer 38

A drop feed.

Question 39

What is the function of the thread take up cam?

Answer 39

Connects to the arm shaft and drives the tread take up lever movement.

Question 40

How do you reduce friction on the needle thread.

Answer 40

Rout the thread through the oil cup for lubrication.