Introduction: Lego Trotbot

This instructables show how to build a Trotbot only use LEGO parts.

Step 1: What Is Trotbot?

Trotbot is one of a mechanical walker design, I known it because I really like Theo Jansen's Strandbeest.

Strandbeest has a little bit limitation for robot because it only can walk on flat surface, Trotbot made to overcome this.

Makezine have a very good article talk about it, I also know it by reading this article. So I do not write duplicate words here, simply read this:

Step 2: Large Torque Concern

The original design mentioned in Makezine article use a pair of LEGO largest torque motors (XL) and use a 1:5 gear set multiply the torque again. In my testing, the torque is too big for plastic. The LEGO parts are very easy to break, so I cancelled the 1:5 gear set.

Step 3: LEGO Digital Designer

LEGO Digital Designer (LDD) latest version is 4.3.11, it released at 2013. LEGO said they don't support LDD anymore, but it still a powerful tools for LEGO design and sharing. You can still download it here:

The LEGO Trotbot design mention in makezine article not only use LEGO and also it require break some LEGO parts and glue it together. And also they does not expose the full steps how to make it.

So I have redesigned it with LDD, it is now only use LEGO parts and not require break any parts. It means all parts can be reuse for next projects :>

Note 1: I am new to LDD, some parts mechanical parts I don't know how to snap together. I think clever people like you know how to make it.

Note 2: If you know how to fix my Trotbot.lxf, welcome send it to me for sharing ;>

Step 4: Bill of Materials

One of LDD best features is it can generate the bill of materials (BOM) list. It is very useful to order all LEGO parts before assembly.

Note: you can order 8 more "CROSS AXLE 4M" and 8 more "CROSS AXLE 8M" for further fine tuning.

Step 5: Assembly

Please follow the attached PDF building instruction to assembly.

Step 6: Motor Control Component

The BOM and building instruction not yet have a motor control component.

The simplest way is to use a LEGO remote control;

You can use a WiFi WebSocket Remote to control it:

Or you can add a MCU or RPi make a robot and turn Trotbot as a robot mechanical part.

Step 7: Fine Tuning

As mentioned in makezine article, the leg motion mechanical is the most important part. There are 2 cross axle in each leg, in building instruction, it is 3M and 7M. You can swap it with 4M and 8M representatively and test the climbing performance yourself.

And also you may see my Trotbot have big feet, it can help to increase the friction on slippy floor.

The Trotbot in this instructables is only a skeleton, you can make it more fancy by your imagination!

Step 8: Happy Playing!

It time to bring your Trotbot outside to play!

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