Addition of a
vac nozzle to suck up the dust.
Big stepper motor
fitted to X axis.
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Next up was 3d milling. This was a whole
new ball game. 3d milling involves a few more steps
than normal 2d routing. 2d routing is easy, draw the
shape in a cad program, save it as a DXF and use KCam
to import the profile and mill the part out. You can
set the Z depth when you import the DXF, so its possible
to make multi level parts.
But true 3d means KCam controls the
Z axis in the same way as the X and Y axis. I wanted
to make a airfoil for a small Darius windmill, so I
designed the part in a 3d program, then used a milling
program to generate the G-Code ( G-Code is the native
language used by KCam, and just about any CNC machine
out there from laser cutters to industrial robots. ).
It took me a few attempts to get the hang of the software,
but I got it sorted and made my first 3d part.
You can download the video here, its
about 2.3 megs in size, and shows the router making
the part above.
Since
this video was taken I've made three big changes to
the machine. I'll document these better in time, but
a quick run down for now......
First up I found a cheap
supply of Acme thread, 6 turns per inch. I had to make
my own nuts(!) from some HDPE plastic, the result was
less backlash and the steppers could run slower for
the same XYZ speed. Next was the microsteppers. I had
heard of Microstepping, where the stepper motor driver
feeds a almost sine wave like signal to the stepper
motor, but microsteppers were expensive, so I thought. Ocean Controls came to the rescue again with a cheap
$99 microstepper module, the M325. The M325 can drive
up to 2.5 amps, and will work as a 1, 2, 4 or 8 step
microstepper. I ordered 3, one for each axis.The difference
micro stepping made was dramatic, over twice the half
step speed. My router would now reliably travel at over
1000mm per minute. Lastly I changed the X axis motor
for a larger motor, again worth the money.
To be continued....
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