Ideas and Insights on Wood Working design and CAM.

[matth]

Wood does not cut similarly to non-linear materials, such as metals or plastics where the material properties are equally distributed. 

Both way cutting doesn't work so well when cutting wood. In my experience climb-cutting is where it is at, this and a combination of logical tool choice along with feed engagement patterns, are critical.

When cutting wood, you have to be mindful of the material's hardness, grain direction, geometry, moisture and on and on. 

Wood holds a lot of energy, and it releases it almost as harmoniously as it changes in moisture content and orientation to gravity.  I mean, think of it on a microscopic level, Wood grain is somewhat LINEAR tubes. Forces on it behave differently, almost always. Like if you can imagine a long tube with water on both ends and air between, if this wood flattens out or stretches, it will pull a vacuum on the grain, so when you cut it the workpiece will end up being smaller than you intended after it sits!

A man has once tried to tame wood. "The end to warping" they called it, "let's pressure treat it," they said, so they fill the wood veins with so many toxins until the potential for movement subsides.

Sorry, personally I feel that if we can make a responsible coating to preserve the wood beautifully and protect it, maybe it won't let it one day buckle, twist or cut. Hopefully.

To the beauty to marvel that is the character of the wood. Knots, Sap-lines, young and old growth. Each characteristic owning disparate differences in force effect. 

The future of wood machining is per workpiece recognition of character and tool path patterns chosen to engage the workpiece to get the best result in machining. 

But we are worlds away from that.

Instead of choosing a manufacturing pattern that avoids the character of wood maybe we can then start to embrace every bit of it. Scrap wood could be almost non-existent.

But then you must consider all of the big wigs wanting consistency in the way that the wood presents staining each unit the same color even when it is the same species, complaining when a little bit of pink or green shows up in Maple. Ugh. Embrace our differences I mutter, like wood I find these people also lack embracing diversity in people. -Though not all.

So I also want to say, how about an idea where we stop staining or painting wood and stop asking our customer what color do you want your wood and instead say what character? It is funny that woods with 'defects' often are cheaper. Seek out a non-yellowing clear coat! Let the native and predictably random character of the wood excite you! I mean have you seen how beautiful Walnut, Cherry, and Maple are?

Any, who

In the future, if we can get segment level control of toolpath I am sure that woodworkers, CAM-oriented, and design ready with Fusion will concur the cutting of wood materials with grain based cutting strategies that can be 'ad-libbed' until Software Engineers get around to understanding the complexities of cutting these systems.

Wood tears out when cutting it wrong.

Cutting forces parallel to the grain split the wood like a knife that a cutter is. 

Dry wood behaves differently than wet wood when cutting on a CNC.

Sorry again, this is Idea Station, allow me to summarize my Idea.

I feel like if I can treat the tool paths generated by your CAM package much like a sketch, I can get more experimental with cutting patterns and practices in a linear, grain, type tool engagement, i.e. cutting Wood. I feel like there could be some patterns that may be lean in machine time that requires switching between climb & conventional by turning the cutter away from the workpiece where trouble is occurring, moving down the part and then changing the tool engagement based on grain & geometry conditions. I would like to test that on a few parts, I have hit 'acceptable' but not perfect results regarding machine time vs. part quality. I can solve this by tooling to sketches, but I don't want to sketch out an entire operation. 

Please know, I don't claim I am all that in cutting wood. I took my years of drafting, modeling, and some design/engineering experience and was given a 3-axis Onsrud Pendulum beast and let loose. It was the rants from skilled and passionate individuals online and at the workplace that led me to understand and learn to love the predictably unpredictable world of cutting wood. These expressions are of my own, I may be wrong, and I should be told so, after all, I have been machining wood only for two years in August.

Wood is maybe one of the only material that with care and time you may be able to source from your back yard. Like days of old. 

Thanks.

MSH | Matthew Harrison

While I was writing this, I realized I should create some drawings to illustrate further, many of the points i have made above. If you are wanting to get more information about what I have said above please let me know what areas need clarification. 

In expressing your undestanding you truely test your knowledge, this is when change happens, as sometimes you learn something new or perhaps more importantly learn that you have been wrong all along.