Tetrix CNC mill

This is a tough project! The aim is to build a mill to engrave letters or little signs into wood. You can find a bunch of cnc machines out of Lego, but no one can cut wood. So here is another example for what you can't build with Lego, but definitely with Tetrix.

The biggest problem is to find solutions for moving the table, because Tetrix doesn't have linear gears or something similar. This problem cannot be resolved by using Tetrix parts. So I bought 3 threat rods and 6 rod couplers for 10 $. Because Tetrix has no encoders in its basic kid and the "High Technic Encoders" are too expensive, I figured out that the "legacy angle Lego sensors" would be the best solution. Those sensors are not the most precise ones, but it would be sufficient for this application.

The next problem was about how to realize the guiding of the table. I found some interesting relations between the different profiles. But you have to try out a lot of things to find an optimal solution, because the most ideas you have, fail often on the whole relations.

The next pics show you some impressions of the construction.

The two pictures below show the guidance of the y and x direction.

Here you can see how I used the rod couplers. To use them as motor-coupler I had to bore them on the motor side up and to make a locking device.

http://www.youtube.com/watch?v=NDFuWjHLxuA

The circle has already been drawed but not filmed because it worked only once ... :)
Wood cutting and circles are coming soon....