One of the latest additions to HSMAdvisor speed and feed calculator is the ability to set manufacturer-recommended speeds and feeds for work-piece materials and groups of materials.

Here is a YouTube video walk-through showing how to add S&F tables into the program https://www.youtube.com/watch?v=AJOgWfgy99U

HSMAdvisor uses Brand Name and Series Name to assign speed and chipload tables to tools.

A new "Speed and Feed Source" (S&F Source) indicator has been added to quickly tell user which speed and feed table is being used right now.

HEM is a relatively new term.

It means High Efficiency Milling. It only became available when constant tool engagement toolpahs became almost standard on most of the CAM software.

Unlike HSM that utilizes chip thinning effect, HEM relies on much larger widths of cut and thus chip thinning does not occur. What gives it its name is much higher material removal rate that would normally be possible.

When you are machining a pocket you are most often only milling at about 50% WOC. But nevertheless you need to calculate speeds and feeds based on the fact that the very first move and every corner will be full slotting action. Which means that the whole pocket needs to be machined at lower feedrate.

HEM uses constant engagement toolpths to make sure that this never happens and that Width of Cut remains optimal. Tool never needs to make a full slot so you can ramp up the feedrate as if you were doing outside profiling.

Here is a video of a 1/2" 3 flute endmill machining a 5/8" deep pocket in aluminum at full depth. Normally this pocket would have been machined in 2 steps at 150 inches per minute.

Using Constant Tool Engagement toolpaths we can go full depth at 0.175" stepover and 275 inches per minute.

The advantage of this method is obvious- Higher Productivity.

HEM is not ideal for all cases and each application merits its own method of machining, but its always nice to know more than one way to do your job.

If you are working in mold-making, prototyping or even in a job shop you have had to use unusual form tooling before in your life.

Form tooling is often used to machine undercuts and other features on regular 3 axis machines that would otherwise require a multi axis machining centre or are not machinable o at all.

The classical example of a form tool is a tear-drop ball mil, also known as a "lollipop". It has a tip with a certain diameter and a much smaller shank that produces enough clearance to machine undercuts on straight walls. It can also be used to regular surface finishing and 2d milling.

Another example is a T-slot cutter that is used to produce key-ways and t- slots

The main thing to consider when machining with reduced shank end mils is deflection and torque.

While deflection is especially dangerous for long tools, torque becomes much more important for tools with severely reduced shank.

Torque required to break a tool is directly proportional to the diameter of its shank.

And when shank diameter is much smaller than the tip diameter it does not matter how short that weak portion is: unless you compensate for it you will snap the tool.

The first thing that crosses the mind in many such cases is "I gotta run this tool very slow". It may take forever, but in many cases job gets somewhat done.

Contrary to that many experienced machinists have been proponents of different approach. Instead of reducing feed rate to the point of rubbing and below, it is much more productive to reduce cutter engagement if possible and leave feed rate settings largely unchanged.

Trying to keep proper chip load is even more important when machining work-hardenable materials like stainless steel and titanium. In those cases rubbing is not just unproductive, it leads to a very premature, in many cases instantaneous tool failure.

Just how much of a cut is possible to take in each particular case is the black magic that separates beginners from seasoned pros.

Not to worry though

Here is an example

Here are the speeds and feeds for supercobalt minicut end mills.

Hanita Varimill II Speeds and feeds Table

Plus Ordering information