Install Node.js and NPM on ubuntu server

Although you can easily install node using the Ubuntu package manager, you'll only get v0.4.something. This is not compatible with many of node's useful modules such as socket.io and is a very old version. Below I explain how to install node and npm on Ubuntu server from source:

Step 1 - Update your system

sudo apt-get update

sudo apt-get install git-core curl build-essential openssl libssl-dev

Step 2 - Install Node.js

First, clone the Node.js repository:

git clone https://github.com/joyent/node.git
cd node

OPTIONAL

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Now, if you require a specific version of Node:

git tag # Gives you a list of released versions
git checkout v0.4.12

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Then compile and install Node like this:

./configure
make
sudo make install

Then, check if node was installed correctly:

node -v

Step 3 - Install NPM

Simply run the NPM install script:

curl https://npmjs.org/install.sh | sudo sh

And then check it works:

npm -v

Code for Calibrating a Reprap Printrbot

I have found many tutorials around the web showing how to calibrate Repraps and Printrbots. They tend to explain the technique very well, so I'll just let you Google that bit, but they often miss out the G code instructions.

To calibrate use this formula:

• (Steps per mm) * (expected distance traveled) / (actual distance traveled) 

Pronterface commands are as follows:

• M501 - show current settings (steps per mm)
• M92 X60 - change X steps per mm to 60 (interchangeable with X,Y,Z and E for Extruder)
• M500 - save new settings