CADding lumber

How to measure with a tape measure

First, you need to know how to measure with a tape measure. I have a lot of them in my Measurement Drawer. You will need to measure all the wood that we have in the shop: 2x4s, 2x6s, plywood sheets, and more!

We will be drawing an enlarged inch, to scale, on an actual board. 

And then you will be marking some lengths, using a tape measure, a pencil, and a speed square:

Once you have correctly and confidently measured using these tools, you are ready to start CADding wood on TinkerCad! Think about how many different sizes of wood that we have piled in the Shop from Cardinal Home Center (for benches and picnic tables) and Better Living (for H.O.W.S. doghouses)!

So why is a 2×4 smaller than 2 inches by 4 inches?

When lumber is first cut from a log, it really is close to 2 inches by 4 inches. But that’s when it’s freshly sawn and full of moisture — what we call “green” wood.

Before it’s ready for use, that lumber goes through two important steps:

• Kiln drying, which removes moisture and naturally causes the wood to shrink.
• Planing (surfacing), which smooths rough edges for consistent size and a clean finish.

By the time it’s ready for your next home project, that 2×4 now measures about 1½ inches by 3½ inches — a standard size used across the industry.

What About Length?

Good news! When you buy lumber labeled 8, 10, or 12 feet long, that’s exactly what you get. The lengths are true to size even though the thickness and width are nominal.

And thanks to U.S. lumber grading rules, those finished dimensions are consistent everywhere — no matter which mill produced them.

On TinkerCad, create a 3d design. Call this design your username and the word lumber (Ex: jwb2f Lumber). Click [Settings] to make sure that you are in Metric and not in Imperial. Your [Snap Grid] should read 1mm. You are going to make a scale model of the wood that we will use, where 1 mm on TinkerCad will be equal to 1" (one inch) in real life.

Start with the 2x4. You will need to measure it in 3 dimensions. Length, Width, and Height. The length will be VERY long, a LOT of inches! Remember that 1' (one foot) is 12" (twelve inches) long!

What other pieces of wood do we have in there? Measure them all!

Finally, in one of my classes, we will rip-cut a 2x6 all the way down the length, so the width will be half the inches. You can copy and paste your 2x6 and then change the width.

Check your table team's work. You will all come up at the same time for me to check and give you a grade. You won't get a second chance, so make sure you all have the same answer, and you are all confident that it's correct!