The whole way even simple surfaced parts are cut has changed for CNC machinists with a clue. What you knew and did only a few years ago is most likely different than what you do now if you wish to stay competitive. Even if you have a home CNC machine shop, the new surfacing toolpath algorithms help you use less tools, help make your tools last much longer and can radically cut down your cycle times. I recently reprogrammed some parts that had operations that took 34 minutes that I cut down to less than 11 minutes. I didn't do this because I'm a genius. I did this because the surfacing toolpaths that these parts were programmed with five years ago are obsolete compared to what's being offered today in better CADCAM systems.

The name of the game today is constant material removal/constant tool engagement where your tool never gets overloaded.

The specific program used in the video link below doesn't matter. What does matter is that you understand the principles and the importance of being able to not only step down the part but step up the part to reduce terracing so that your semi- finishing or finishing tool never engages radically different amounts of material. This is a very simple part but the concepts I'm discussion and what's shown in this video are way over the heads of CNC machining morons like Mark Wieber, iggy, Tom Gardner, Larry Jackass, Oh Danny Boy, etc and so is how to machine a part like this. A machining moron like iggy would tell you to buy a casting. What if a casting isn't available? What if you want a stronger part than a casting? What if you don't want to wait? What if you're cheap and you have extra material from a job you did that's paid for? What about the pride in doing it yourself? So how about: **** that ignorant scrap everything cocksucker, build your skill set and knowledge and learn how to make whatever you want!

It's my intention to continue to document the new ways surfaced parts and even prismatic parts are being cut by better CNC machinists. That may or may not include making my own videos depending on the level of interest shown. I don't expect much interest at all because Wieber and his cult of idiots have destroyed this newsgroup and driven just about every decent machinist out with their tea bagger bull****.

Here is the video. It's pretty straight forward and shows the old way and the new way to rough simple parts out:

http://youtu.be/2r3PdpOdiS0

Next up:

Advanced methods that apply to simple prismatic parts. I'll explain what they are and show how they save time and make programming parts easier. They also eliminate guess work and cut cycle times.

Part Two:

Stock models allow toolpath engineers to apply intelligent toolpath to their *as machined* part models. Before we can get to stock models for toolpath surfacing, I think it would be helpful to show how stock models are created and how they are used to save time and prevent needless boundary creation to properly machine even simple prismatic parts.

Without a stock model, the toolpath a CADCAM programmer creates has no idea what the existing condition of the *as machined* part model is. Basically, the only reason a toolpath engineer creates a stock model is so that they can *add intelligence* to the toolpath they create in subsequent machining operations. Valid reasons for creating stock models are so you don't machine air and so you can make your toolpath *aware of the existing stock on the model left by the previous toolpaths you created*.

As this and future videos will clearly demonstrate, creating and using a stock model is absolutely critical for tool life, cycle time, good surface finish, etc.

http://youtu.be/zCg-F02YSgo

Part Three:

Now that we understand the basics of what stock models are used for and have explored how they are used on simple prismatic parts, it's time to explore how we can use a stock model on surfacing toolpath. We have previously covered how a stock model can represent a single previous machining operation as well as many previous machining operations.

The following video shows how creating a stock model of your parts current as machined state can be used to:

Control how the tool will engage unmachined stock.

Control the maximum depth of cut the tool takes.

Control removing parts of the toolpath that waste cycle time by jumping all over the part removing little or no material.

Help you to make the tool do what exactly what you want it to do.

http://youtu.be/1VZ4wu5netg