## Introduction: QuirkBot Walker

This is a tutorial for building a single servo motor walker robot using straws, strawbees, one servo motor and a QuirkBot (but any other arduino might work even not so nicely ;P )

## Step 1: Material

The basic material you'll need to build this is:

- 14 straws with the same size (or close enough)

- 30 single leg strawbees

- 2 double leg strawbees

- 1 Scissor

- 1 Rubber band

- 1 Servo motor with horn

- 1 QuirkBot

## Step 2: Assemble the Legs

We cut the straws all the same size for a practical reason but the inner part of our robot leg is actually a bit smaller so you'll need to cut it to make sure you'll have a 90 degrees angle between the external part of the leg and the "shoulder/hips".

Pay some attention to the strawbees angles and locks but don't be afraid of commit any mistake since it's just a matter of unplug, fix and plug again.

## Step 3: Servo Case

This is perhaps one of the most important parts of this robot because if the servo is too lose, it turns itself instead of move the structure.

Making this servo case can be a bit tricky if you never touched a strawbee. If you are having troubles with this one, I strongly recommend to play around and find your own solution (and reply me with it! I'll love to check it out).

To make my servo even more stable in the case, I used a rubber band (I love rubber bands!)

## Step 4: Attaching the Servo Horn

Make sure your servo horn is tight enough inside the strawbees holes, otherwise it will slip away.

Also pay attention to put the horn inside one of the straws. This is very important!

If you want to move stronger and faster, screw the servo horn. I recommend to do this as a very final step.

## Step 5: Diagonal Axis

This is a trick.

If you want to move 2 parallel axis with a single servo, attach their joints with a perpendicular axis.

Do it as a diagonal axis you'll have a cool inverse rotation, very useful for walking robots in general.

## Step 6: Make It Stronger

Triangles. The solution for your weak wobbling structures probably is: Triangles.

For this we'll need 4 extra straws bigger then the first size straws.

Play around with this extra straws to create the best angles and spacing for your robot legs.

Tip: Watch the nature, try to copy animals legs sizes and angles. Fail, rebuild, fail, rebuild again. This is evolution, baby! :P

## Step 7: Code It

I recomend this code here:

https://codebender.cc/sketch:66977

Tip: Run your code first with the servo horn detached and then attach it to the servo, this will prevent your structure to blow out if it's too strong.