Welcome to my series of LEGO build challenges. While I imagine that most of you will use LEGO for these builds, there is no reason that you can’t use anything else. Build it with popsicle sticks, cardboard, bits of plastic from your recycling bin. Anything! I’m using LEGO because it’s easy, quickly to change, and reusable (and I have lots).

Before we get started with Build Challenge #1, I though I would quickly explain the basic names of Technic parts, because I’m going to be using them a lot as we go along. So, if LEGO Technic is new to you, check this out.

If you feel like you are ready to go, read on!

Build Challenge #1 – Let get started

Challenge #1 is to build a mobile. The type of mobile that hangs from the ceiling and spins around. The key thing about a mobile is that it stays in balance, even though the objects hanging from each arm might be a different size, and even when an arm has a different number of objects hanging on it.
In the video #1, I linked another video that talks more about the effects of leverage and mechanical advantage of levers. If you missed the link, it here.

Build Challenge #2 – Lifting with ropes

Welcome to Build Challenge #2. This challenge is all about building a mechanism to lift weight with a rope and pulley. Builders will need at least one LEGO pulley and a winch, or other parts that you can be used as a pulley and winch. If you don’t have enough LEGO to build a lift structure, you can build it on the under side of a chair or table.

This challenge includes 3 difficulty levels:
Easy: Build a lift mechanism that uses at least 1 pulley as a redirect at the top of the lift and a winch to wind up the string/rope to lift the load.
Medium: Same as easy, and then add a second pulley to create a 2:1 Mechanical Advantage.
Hard: Same as medium, and then create a track mechanism to allow the load to move back and forth, so that the load can be raised in one spot and lowered in a different spot.

If this seems a little too complicated, you may want to start with the 3 instructional videos I have created:
Introduction to LEGO Technic Pulleys
Creating Mechanical Advantage with a pulley
Building a Spool and Winch

Introduction to LEGO Technic Pulleys
This short introduction explains what a pulley is, what a Technic pulley is, and what you can do to make a pulley, if you don’t have any LEGO pulleys.
The video demonstrates two simple uses for a pulley; a redirect, to make work easier and a belt drive.

Creating Mechanical Advantage with a Pulley
This video shows a simple demonstration of mechanical advantage using string, a pulley (really just a pin) and a winch.
The demonstration shows a 2:1 Mechanical advantage, first by showing two figures lifting something together, and then by removing one of the figures.
The Video doesn’t cover load distribution, because it would have been too long. In short, both figures are holding slightly more than half of the weight because both ropes under tension at an angle, which gives mechanical advantage to the load as it pulls down on the ropes. That might get into a future video about tension and load distribution.
The video also does not cover a 3:1 mechanical advantage or greater, for which I recommend this great cartoon.

Building a Spool and Winch
Winches and Spools are an essential part of using rope, string or chain in your LEGO builds. They can be used for cranes, drawbridges, tow/lift lines, gondolas and so much more.
This video is a simple demonstration of how to build a spool and winch to wind up a rope. The video also shows one simple way to add friction (resistance) to the mechanism, so that is doesn’t easily wind or unwind.

Build Challenge #3 – Coming Soon

LEGO® is a trademark of the LEGO Group. The LEGO Group does not sponsor, endorse or authorize this challenge or this use of LEGO elements.