This post is geared for the woodworking types.  To use the CNC machine, the user is not required to have a PHD in Electrical or Mechanical Engineering. If that were the case then very few people would ever use the machine.  The post is catered for people in the woodworking industry who want to use their CNC Retrofitted Mill/Drill to cut wood.

Machine Setup

First of all, do not be intimidated by this section.  Setting up the machine did not require any special mathematical concepts to be applied.   Before you start cutting wood, you need to verify 2 things;

• Does your machine move in the correct direction?  Or the direction you think it will move?
• Does your machine have the correct Counts/Inch to move the correct location?

Does your machine move in the correct direction?

Your machine should follow the coordinate system as shown.  Assuming, (0,0) is at the origin.

What this means

• If you move the X axis to the right of the origin, X should increase in value.  If you move the X axis to the left of the origin, X should decrease in value.
• If you move the Y axis up from the origin, Y should increase in value.  If you move the Y axis down from the origin, Y should decreases in value.
• If you move the Z axis up, Z should increase in value.  If you move Z down, the value will decrease.

This is very straight forward.  To verify;

Run KMotionCNC.exe and you will see the following dialog.  HIT THE “INIT” BUTTON.

1. Zero out the X, Y, Z.
2. Move the machine to the right.  X should be positive and increasing in value.  The value can be verified in the DRO.
3. Move the machine back to X=0.
4. Move the machine to the left.  X should be negative and decreasing in value.  The value can be verified in the DRO.
5. Repeat the steps for the Y and Z axes.

Pretty simple.  Right?

Does your machine have the correct Counts/Inch to move the expected distance?

Finding the Counts/Inch for each axis, takes some effort.  You need to find out;

• What are the Counts/Inch for X, Y, Z axis of the table.

Place a ruler onto the table and insert the edge finder as shown.

1. Run the KMotionCNC.
2. Run KMotion.exe and select the “Console” and “Axis” menu items.  You show see the following dialogs together;

1. Use the joystick to move the stage.
2. Move the edge finder on the X-axis to a known position.
3. In the “Console” dialog execute Zero0 command.  You will see a 0 counts on the “Axis” dialog.
4. In the KMotionCNC dialog zero out the X-axis.
5. Move the joystick 1.0 inch on the x-Axis.  You will see the Counts on the “Axis” dialog.
6. Repeat the same process for the Y and Z axis.  To verify the Z axis.  Move the edge finder up and place a 1 inch block between the edge finder and the known surface.

The results;

1. X-axis has 113,790.13 Counts/INCH.
2. Y-axis has 71,838.17 Counts/INCH.
3. Z-axis has 116,675 Counts/INCH

 

Select CNC Router bits for Your Mill.

To cut wood on your mill, it is best to use the CNC router bits made for wood.  The flutes are larger on the wood working bits so the sawdust can escape efficiently.  There is less of a chance of the bits clogging.  The metal bits (especially end mills) do not work as well on wood.  The metal bits are designed to run at slower speeds, 100 rpm or less.  Metal bits will clog at higher speeds.

The wood working bit seem to work the best at 2000 rpms.  If you run them at 100 rpms, the wood will chip badly.

I tested the;  End mill, 90 degree V groove, Tapered ball nose bits made by the “freud” company.  I purchased the bits from the Rockler Woodworking Store in Northgate, north of Seattle WA.  This store is their Superstore, which is huge.  The staff was very helpful.  They knew where everything was located, and they knew the product well.   Another benefit, Rockler also carries the bits with the 0.50 inch shank.  Most places only carry the bits with 0.25 inch shank.  The bits shown in the photo are the 0.25 inch shank.

If you don’t remember anything else; just remember the CNC router bits are only for wood and plastic but not metal.

Learning CAMBAM.

Now that you have the machine ready and you have selected the router bits, you need to learn to use CAMBAM to generate your G-code.  I recommend watching the first 2 videos.

All of the video are good and shorten the learning curve to use the software.  Once you have generated the G-code, you can simulate it in KMotionCNC.exe.

The Round Box Design in CAMBAM

The box is circular.  The design will require a 2 files; 1) for the box, 2) another for the bottom lid.  There is a learning curve for CAMBAM, but it was not large for this project.

Round Box

The round box is just a piece of wood (5.5″, 5.5″, 1.5″) that was cut into a circle with a hole in the middle.

Here is the finished product

 

Round Box Lid

The Lid is just a piece of wood (5.5″, 5.5″, 0.75″) that was cut into a circle with a circle pocket in the middle.

Here is the finished productBef

The milling fixture

Before you start cutting wood you need to make a fixture to hold the part.  The fixture prevents the blade from colliding into the table directly.  The part is held to the fixture with 6 screws and the fixture is clamped to the table.

Videos to create the round box.

The CNC machine cutting the Box

 

The CNC machine cutting the Lid

 

 

Final Product

After the CNC Mill is done cutting the wood.  Remove the parts from the fixture.  This is what the final product looks like.

Please let me know if you have any questions or comments.