Introduction to CNC Routers
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If this is your first attempt at finding out about CNC Routers, you will be glad to know that this field has made great gains in the area of affordability in the last couple of years.  CNC Routers are now being used in many home shops and small shops.

Lets look at the parts that make up a CNC Router.  You can divide the parts into the following functions:

• Mechanical base - The mechanical base is the basic frame and structure that hold everything together. For my current machine I have used aluminum extrusions. The frame could be made out of a number of different materials.
• Linear rails and bearings -  The linear rails and bearings can be the most expensive part of a CNC Router system. There are a number of different rails and bearings being used on small CNC Routers.  The most common are the rails and bearings made by THK, IKO and Star.  They are the best, but the most expensive.  On my new machine I am using Bishop-Wisecarver "V" wheels on the Y axis.  The Bishop-Wisecarver "V" wheels are a  less expensive and are ideal for the Y axis.  There are other rails and bearings being developed.  One is the new Black Diamond linear guides.  They look similar to the IKO rails, but use a plastic insert in place of ball bearings.
• Stepper Motors - Stepper motors are a unique type of motor.  They move in discreet steps. A typical step would be 1.8 degrees of rotation (full step). They can also be moved in half step, quarter step and micro step.  If you are interested in how they work internally, just do a search on the internet and you will find all the information that you will ever need.
• Servo Motors. Servo motors can be used in place of stepper motors.  Servo motors are starting to replace stepper motors for many applications.
• Lead Screws or Ball Screws - On my system stepper motors are connected to lead screws. The lead screws are attached to the moveable elements of the X, Y and Z axis.  This gives the machine movement on all three axis.
• Stepper or Servo motor drivers - This is the one item that we have seen a dramatic drop in price in the last year with the introduction of some very nice drives from Gecko drives  www.geckodrive.com. The drivers are the key element that makes the stepper or servo motors run.

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