I was a little nervous when it came to building up the plastruder. It seems like a place that many things could go wrong. I got the MK4 plastruder from MakerBot. The build instructions on their wiki are pretty straight forward. Also, I am thankful for the makerbot google group for the support they give. I have been trolling and learning some of the pitfalls people have had in building the current revision. I see the wiki has been updated to address those. Awesome!
Now that I have built one and all measurements look good I feel like i can tackle another without too much problem. The hardest part for me was the fine wire of the thermistor. It was like to hairs and a spec of glass. I felt that if I sneezed, it would be gone.
The next challenge is to mount the plastruder to the Z sled.