CNC routers have been widely used in commercial
woodworking for years, and now they’re making their way into hobbyist shops.
Some woodworkers just don’t believe in
using CNC routers. They believe that someone who cuts and shapes parts
with a CNC router is not a craftsman, and has little or no connection with the
materials he or she uses. As someone who began his woodworking career with a
strong interest in hand tools, I can understand this point of view. However, my
time in the woodworking industry has taught me that proficiency with CNC
routers requires more creativity and skill than most people probably realize.
No matter what tool you use to cut or
shape a piece of wood, you need to know how the material is going to respond.
When you’re cutting end grain, you’re going to tear out the back edge of it
whether you use a handheld router, hand plane or a CNC. You need to clamp a
block behind your board, chamfer the back edge or take some other action to
prevent this tear out.
CNC routers cut solid wood just like
portable routers and hand planes. They need to take shallow cuts and multiple
passes. Setting a machine’s feed rate too low will result in burns, and setting
it slightly too high will give you chatter. When a cut is too deep, a CNC
router bit can break. Bit selection is also important, and you need to be able
to choose from options like single-flute, straight flute, spiral flute, up-cut,
down-cut and compression.
Work holding on a CNC can be a real
challenge. Most commercial machines use vacuum systems to keep work pieces in
place, with somewhat inconsistent results. If a part is too small, the vacuum
won’t hold it. Operators need to know how to build jigs for these situations
and how to accommodate them in CNC programs. Hobby machines usually rely on
clamps or fasteners for work holding, and knowing how to arrange them, as well
as how to program a machine to avoid routing into them requires skill.
Programming a CNC machine is an ability
that takes time to master. You can learn the basic G Code commands that control
a machine very quickly and use them to create simple parts. However, to really
exploit a CNC’s capabilities, you’ll need to learn some kind of CAM software.
Once you do, you can cut intricate 3D shapes and ornate carvings.
If you’re interested in learning to use
CNC routers for your woodworking projects but are a little intimidated after
reading the above, don’t be. Learning to work with CNCs is just like learning
to work with hand tools; once you know your material and a few basic skills,
you’ll be able to complete some simple projects. With practice, you’ll be able
to do more advanced work. The real fun of CNC is in the learning process:
exploring the code that drives the machine, using the software and figuring out
how to hold difficult work pieces. I can tell you from experience that this
process can be one of the most exciting and rewarding parts of your
woodworking.
You
can build your own CNC router for woodworking. Take Nick’s Popular Woodworking
University course, Build
a CNC Router. You’ll get a parts list, step by step instructions, a SketchUp
model and dimensioned drawings.
No comments:
Post a Comment