TECHNIC Liftarms: Angles Built In

How are you LEGO Mindstorms NXT hobbyist? I hope, You still remember about Tilting the LEGO World: Diagonal Bracing. This posting continue it. As noted earlier, over the past several years LEGO has introduced a number of new TECHNIC parts that divert from the concept of straight beams and 90-degree connectivity. We could review numerous parts here, but there simply is not enough room in the my posting for this. Some of the more popular ones fit in the common group of studless beams, called l/ftarms. They come in many shapes and sizes, you can use them to connect parts at differing angles, and you often see them in robot grabbers, fingers, ball casters, and so on. Figure 1.9
shows a sample ofliftarms from the TECHNIC line.

Figure 1.9 A Variety of Liftarms

Tilting the LEGO World: Diagonal Bracing

Hello, LEGO Mindstorms NXT hobbyist! Who said that the LEGO beams must connect at a right angle to each other? The very nature of LEGO is to produce squared things, but with the advent of studless parts, diagonal connections are mainstream now, making our world a bit more varied and interesting, and giving us another tool for problem solving. 

Lego Mindstorms NXT hobbyist, this posting relate past posting about squaring lego world vertical bracing. You now know that you can cross-connect a stack of plates and beams with another beam. And you know how it works in numerical terms. So how would you brace a stack of beams with a diagonal beam? You must look at that diagonal beam as though it were the hypotenuse of a right-angled triangle. Continuing from the previous sample, Figure 1.8 adds a cross-brace to support the structure and provides a sample for this next bit. Now proceed to measure its sides, remembering not to count the first holes, because we measure lengths in terms of distances from them. The base of the triangle is eight holes. Its height is six holes: Remember that in a standardized grid, every horizontal beam is at a distance of two holes from those immediately below and above it. In regard to the hypotenuse, it counts 10 holes in length.

Squaring the LEGO World: Vertical Bracing

Welcome back Lego Mindstorms NXT hobbyist... We continue our discuss about building robots with lego mindstorms NXT past time. Why do we care about all these relationships? To answer this, we must travel back to the late 1970s when the LEGO TECHNIC line was created. Up to that time, LEGO was designed and used to build things made of horizontal layers: Bricks and plates integrate pretty well when stacked together. Every child soon learns that three plates count for a brick, and this is all they need to know. But in 1977, LEGO decided to introduce a new line of products targeting an older audience: LEGO TECHNIC. It turned the common 1 x N brick holes into what we call a TECHNIC brick, or a beam (Figure 1.5, left). These holes allow axles to pass through them, and permit the beams to be connected to each other via pegs, thus creating a whole new world of possibilities.

In the late 1990s, the advent of studless beams (Figure 1.5, right) opened the door to alternative building options. One of the best sets in TECHNIC history is undoubtedly the 8448 Super Street Sensation, which is built almost entirely from studless parts. LEGO was clever with its approach here. Instead of using beams to construct the chassis and plates to provide the "shell" or "form" for the model, the chassis was built using studless beams and its style was handled by fairing panels, allowing the curves of the car to "flow" with the design. LEGO did this to reduce costs: Less material required equals a cost savings in production. You can see a great example of this if you compare the 8448 Super Street Sensation to the classic TECHNIC 8880 Supercar. Compare their approaches to construction, and their weight.You will notice significant differences. The 8880 gets all its design cues from classic TECHNIC beams, whereas the 8448 uses fairings and flex axles for its design.

Figure 1.5 The LEGO TECHNIC Beams

Building Robots With Lego Mindstorms NXT

Introduction

Before you enter the world of LEGO robotics and building robots with Lego Mindstorms NXT, we want to be sure you know and understand some basic geometric properties of the LEGO bricks and beams. Don't worry; we're not going to test you with complex equations or trigonometry. We'll just discuss some very simple concepts and explain some terminology that will make assembling actual systems easier from the very beginning. You will discover which units LEGO builders use to express sizes, the proportions of the bricks and beams, and how this affects the way you can combine them with different orientations into a solid structure.

In the past few years, there has been a shift from building with TECHNIC bricks and beams to building with studless beams, pins, and connectors. After we introduce some basic concepts, you will be exposed to these new ideas and see examples of how you can use studless building. We encourage you to try to reproduce all the examples we show in this chapter with your own LEGO parts. If for any reason, you feel that what we present is too complex or boring, don't force yourself to read it. Skip the chapter and go to another one.You can always come back and use this chapter as a sort of glossary whenever you need it.