This February CamInstructor.com hosted a virtual webinar event mostly dedicated to advanced MasterCAM programming.

They called it the Big Event.

I myself watched at least 2 streams. But since it was a whole day thing, only missed a few.

Luckily they published all the videos on their web site:

Check it out before the link expires or they take it down!

Often times CNC programming tutorials only teach you how to create the tool-paths and not enough attention is paid on showing how to properly hold parts being machined.

At the same time efficient workholding is an art in it self and mastering it could drastically improve shop productivity and accuracy.

Without further ado let's jump into the workflow.

Step 1. Analyze the Drawing and the Model

We would have to look at the drawing, tolerances and the CAD model to develop the machining strategy.

This particular part has tight (+/- 0.001) tolerances between the features located on the top and the bottom sides. In addition to that it has a 2.5 degree draft angle on external walls.

Thus I decided to not use the soft jaws approach and machine it in a fixture. Soft jaws are generally OK for tolerances down to +/-0.001" but because of the draft angle the part would always want to pop out of the jaws.

1. Finished Part 2. First Op: Before 2. First Op. After 3. Machined Fixture 4. Second Op: Bearing Seat 5. Third Op: Finished Part

3D Prining is about to to take over traditional machining the same way CNC Machining took over manual machining.
Eventually 3D printing will replace casting too.

Since 3D Printing does not require complicated setup and programming, this in turn will lead to massive loss of machining-related jobs.

Read more to see if this is true!

Before we start milling away our stock we first need to get down to the required depth.

This is not a problem with external features when we can plunge outside.

When machining closed pockets, however, we need to find a way to get down to the machining depth first.

As usual there are several ways to get the job done. The plunging methods listed here are not ordered by their preference.

For various machining operations on different materials some may be more preferable than others.

Straight Plunging into a larger Pre-Drilled hole

This is one the best ones in my opinion.
Very few machining modes can compete in effectiveness with drilling and this method will get you the best combined tool life on most materials and (in case of many deep pockets) the least machining time, even when tool change time is factored in.

One of HSMAdvisor users asked me for help figuring speeds and feeds for machining stainless on his underpowered Tormach 700.
He volunteered to send me a model to work on, so I decided it was a good opportunity to make a learning video and share it with everybody.

I must say programming for such a low-power machine is a lot harder than for a full-blown production VMC where you are not worried about stalling your machine with anything under 1" in diameter:

Your thoughts and comments are always welcome.

We are actually listening to our users!

Latest advances in tool technology make milling of high carbon and tool steels as reliable and predictable as benign aluminium alloys.

In this video a large 4140 steel component is being roughed out at 2700RPM and 600 inches per minute.
While achieving  impressive material removal rate (20 pounds of steel machined off in a matter of half an hour!) the tool life puts the old school square shoulder endmills to shame.

Yes, it could(and should) have been machined using a bigger cutter, but I wanted to put the tool to the test.
And it performed beautifully: Was able to surpass the recommended starting speeds and feeds by at least 170%!

It does not annoy me anymore!

Originally this part was programmed for and machined in 6061 aluminum, but when production run came, material was changed to HRS and then to SPS (4140).

Luckily reprogramming using HSMAdvisor hook for MasterCAM is a bliss.

Mere 5 minutes and all speeds, feeds, depths of cut, etc. were changed to safe and productive values.

New Material

Quite often I see people asking which text editors others use to work with their G-Code.

Some even suggest paid ones.

I am using a free general-purpose advanced text editor called Notepad++.

It is so flexible, it can recognize the language you are working with and turn on the language-specific highlighting for even the G-Code.

I created my own Language profile for it. It is attached to this article so that everyone can download it.

Below is how you can apply this language profile to turn on g-code highlighting:

G-CODE_N Language G-CODE DARK Size:0.01 MB

Being a CNC Machinist/Programmer is sometimes more than simply creating a program and machining the actual part, often times it is about creating efficient and accurate fixturing.

In this little project:

I had to machine rectangular cut-outs and drill holes through an already-turned steel ring. Then I had to part each ring to 4 equal pieces.

There were about 100 such rings that worked out to 400 pieces in total.

After drilling holes on an indexer I had to machine a fixture to hold my part through 2 remaining set-ups.

First half of the fixture consists of the expanding mandrel:

The work-piece would be mounted on it like so. A hole on the side is used to properly position it:

Did you know there are three ways you can touch off your tools?

Because of how Machine Offsets add up, there are several ways CNC machinists can set their Tool and Work Offsets.

This is especially true for Tool Length Offsets.

Tool Offsets can be either Positive or Negative.
Depending on your Machine Shop equipment you should use one or the other.

Regardless of how you set your tool length offset, you apply it the same way.
Right after the tool change and after turning on your spindle and moving to your X Y position above the part.
The very first absolute Z movement should be the line where you apply the tool length offset.

Positive Tool Offsets (gage line tool length offsets)

In the case of Positive Tool Offsets, the offset represents the Length of the tool measured as a distance from the Gauge Line of the spindle (typically spindle nose) to the tip of the tool. The longer the tool, the larger your Tool Length offset will be.