Distance Measuring - Drafting 1

BASIC DISTANCE MEASURING

The imperial system is the system of measurement used in America. This is what we will be using here at Workshop Houston.

The main units of distance in the Imperial system that we will use are inches and feet.

The Imperial system divides inches into fractions of inches. So when you do not have exactly one inch, you use a fraction to express the exact distance like “4 and 3/4 inches”.

Inches on a ruler are usually divided into 16 equal pieces.

Fractions

Fractions represent parts of a whole. In this case, they are parts of an inch.

The bottom number of a fraction – the denominator – is the number of equal parts the inch was divided into.

The top number of the fraction – the numerator – is the number parts you have. For example, 4 and ¾ inches means we have 4 whole inches and 3 of 4 equal pieces of the next inch.

The figure below shows an inch divided into 16 pieces. If it’s divided into 16 pieces, why do some fractions not have 16 as the denominator? Good question. Find out why on the next page.

Simplifying Fractions

Sometimes the same amount can be expressed by more than one fraction. Even though the numbers in the fraction change, the amount stays the same. For example:

In the first circle, we have 1 piece out of 4 total, or ¼. In the second, we have 2 pieces out of 8 total, or 2/8. The amount we have has not changed, so we can say that 2/8 is the same as ¼.

When we simplify fractions, we want to make the top number (the numerator) as small as possible. To do that we need to evenly divide the top number, but whatever we divide it by, has to divide into the bottom number, too.

So to simplify 2/8 to ¼, we divide both numbers by 2. Divide by the biggest number that goes into both the numerator and denominator.

Let’s do one using an inch. In the image below, we have an inch divided into 16 pieces. Count them to the end of the gray line and we have 12 of them, for a fraction of 12/16.

Now simplify:

Copy this image and label it on the next page:

Hint: Note how the lines are different lengths, and the denominators of the fractions on each length. 

TO DO: Complete the ruler worksheet.

Safety Sheet

Safety Sheet

Cutting Tools

Metal cutting tools typically operate at 10,000rpm – plenty of speed to do serious injury. They shoot sparks when cutting, which are small bits of hot steel. As with any spinning tool, loose clothing is dangerous as it can get caught by the tool and pull you into the spinning blades.

The most important safety tip is to be aware of your surroundings. Pay attention to what’s happening around you as well as what you are doing.

Proper safety gear for cutting tools includes:

1 – Eye protection. These prevent sparks from getting in your eye, where they can rust and continue to cause injury after the fact.

2 - Ear protection. Cutting steel is noisy.

3 – Dust masks. Steel dust is abrasive and breathing it in will cause scratches in your lungs.

Epoxies , Body Filler, and Paint

These chemicals are harmful if inhaled, ingested, and sometimes harmful to the skin. Many epoxies and body fillers, ie Bondo, are exothermal reactions when the two parts are mixed. That means they generate heat, so if some of it got on your skin after mixing, it can cause burns. Most of the time you will be sanding these materials after using, and the dust, like steel dust, can be harmful to your lungs.

Proper safety gear for adhesives includes:

1 – Eye protection

2 – Dust mask or respirator (respirator for paint and fiberglass)

3 – Nitrile gloves

Welding

Welding creates extremely bright light due to the heat necessary to melt steel. This light is strong enough to cause eye damage, similar to staring at the sun. There is also spatter and sparks, particularly with MIG welding, created during the process. These sparks are a few thousand degrees, which is certainly hot enough to cause serious burns and pain. Welding also creates harmful gases, which should not be inhaled.

Proper safety gear for welding includes:

1 – Welding hood or goggles. The welding hood is a must for MIG welding. The darkened welding goggles may be used for torch welding.

2 – Welding gloves. These are thick leather gloves that cover up the forearm.

3 – Long pants. Sparks can land anywhere, including inside your shoes. Pants are a must.

4 – Welding jacket. These jackets prevent your clothes from burning due to sparks.

Welcome to the Chopper Shop! 

The Chopper Shop is a positive environment. We have fun building cool bikes and other projects.

In Chopper, making fun of others, their designs, or work is unacceptable.

There is no horseplay allowed in the shop, as the tools in Chopper can be very dangerous and cause serious harm. Playing around is not the reason to be in Chopper, and it’s dangerous.

PROGRAM RULES

Respect Yourself

• Give your best effort
• Take responsibility for your actions
• Tell the truth – lying is unacceptable

Respect Everyone

• Share the resources of the shops
• Be positive, supportive, and encouraging
• Treat everyone like you would like to be treated
• Teasing, trash talking, bullying, yelling, and fighting are unacceptable

Respect the Shop

• Follow staff instructions
• If you don't know something, ask!
• Use all tools and equipment correctly
• Clean up, even if it’s not your mess
• Theft is unacceptable

Be Safe

• Be careful
• Use proper equipment
• No playing in work spaces

Consequences:

If you do not meet Chopper Shop behavior standards, you will be given a written warning. If you continue to have behavior issues, you will face further punishment and possible expulsion.