Lately there have been a lot of really interesting HSM topics on PracticalMachinist forums.

In one of them a guy who owns his own resharpening business posted a video of his endmill milling a block of D2 hardened to over 60 RC.
The forum topic is located here First try on D2 62Rc(video)

Here is his post so you know what we are talking about:

In the ensuing discussion i posted my own take on how and why HSM works

HSM works in many ways.

1) Reduced cutting time per edge per revolution allows it to cool down more.
2) Chip thinning allows to increase chipload (advancement per tooth per revolution)
3) Increased depth of cut combined with shallow radial positively affects deflection. Tool bends less as it is more rigid towards the tool holder.
4) Higher cutting speed actually reduces cutting forces as heat generated in the cutting zone makes it easier to shear off a layer of metal. Yet because the time of contact is so small, most of the heat is carried away with the chip.
5) Higher RPM also allows to get rid of hot chips faster thus further reducing heat transferred to the tool.
6) Higher feedrate actually reduces relative cutting speed.
7) At high axial engagements more than one flute is in contact with the workpiece at different points along the axis of the tool. This too helps combat vibrations and chatter.
8) You are using more of the tool than just its tip, so technically you can do more work with one tool before it gets dull.
9) lastly it looks cool as hell and is very impressive. Whenever we know visitors or bosses are coming we try to make sure some HSM is going on even if application does not merit that
I am not sure if the air that is moved by the endmill is doing much, but i suspect he didn't mean exactly that.

I have been asked to create a tutorial on how to work with the tool library, so here it is.

myCut Tool Database is quite a unique thing.

It not only contains all of your tools, but also each and every tool can have multiple operations or "Cuts" attached to it.

Everything is very simple.

Database contains Libraries

Libraries contain Tools

And Tools contain Cuts

Each entity behaves according to specific rules and "knows" specific kind of data.

Please read more to learn how it all works.Read More 

I have just uploaded a new release of HSMAdvisor.

I have decided to extend trials every time major releases come out.

This will happen every several months or so.

This release is pretty big. So every one who has not purchased yet gets 30 days more to play with it.

We have material cross-reference tool.

It allows you to quickly figure out material group for a large number of materials. Around 1000 of them.
You can access it by pressing "MORE" button next to material drop-down list.

Here is it looks:

Second Big thing is new tool life estimator.

It allows to show you how tool life reacts to changes in speed, feed rate and depth of cut.

It is a percentage based on normal shoulder milling cut that should equal 100%

Nobody else has this feature- it is absolutely unique to HSMAdvisor and that is in part why i decided to extend trials this time.

Besides tool life gage there is a new tab in results area.

It is called Gages.

It shows important information like what percentage of deflection, torque and machine load we are running at the moment.

It helps to figure out at a glance if something is out of whack.

As always feedback is welcome.

I was originally going to introduce new License types on september the 1st.

But it turned out to be a little harder than i thought and everything got delayed by almost one month.

The revised date of september the 30th is still standing though.

So until then 3 seat license will still be available for 75$ and a new single seat will be available for just 49$ !!!

If you have been procrastinating, this is your time to save.

Also check out my Online store that i coded myself.

http://www.hsmadvisor.com/index.php?page=buy

Here is a video of a 3 flute Hi-performance endmill slotting aluminum 0.75" deep per pass.

Well, not entirely slottimg, more like pocketing, but the very first move is a full width slot.

Stepover is 0.4"

First i calculated the cut on HSMAdvisor.

Used 6061 aluminum as material and HP endmill at a tool type.

Tool torque and deflection limits were both set at 100% and performance slider was at maximum.

This is what it came up with:

S9127 RPM 125 IPM.

Full slot, 0.75" deep.

45 in^3/min mrr.

Looking at how easy it went i think i should allow for more load in my calculator.

If you have not yet tried HSMAdvisor, make sure you do.

You will be amazed at how much productivity you have been missing out on.

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 Read More 

Hello gentleman,

This has been a great run.
Many of suggested features were implemented.
All of the reported bugs fixed and still there is so much to do left.

Out "get it for free" program however has ended.

Here is a list of people who qualified for a free license.

Users who earned at least 2 points got qualified!

Pleaase send me email at cnc@zero-divide.net with your:

Name
Last Name
email address
Computer ID key

Those are users who gave suggestions on support forums.

If you wrote me emails, please get in touch with me anyway. Most of my email contacts who was involved into beta-testing have already gotten their keys.

Qualified users who suggested by email are:

• Stan stanmc@****.net
• David C. Allen
  

If you feel left out please get in touch with me. i could have forgotten somebody.

HSMAdvisor is going fully commercial.

After September the 1st 30th, three seat license for HSMAdvisor currently available for just 75$ will cost 249$

Here are final prices for different packages that will be available:

Basic Individual License

• Single Seat  ___________99$
• Three Seat   ___________249$ (15% savings over single seat)
• Five Seat     ___________349$ (30% savings over single seat)

Special Company-Wide License

• Unlimited number of seats within company premise ___________email Quote

Hurry UP you only have few days left!!

For the list of people whos suggestions and feedback were deemed valuable and who will get a free license please read here.

HSMAdvisor version 0.5 has just become available on downloads page.

There are many improvements and fixes in there.

But the most noticable one is improved Circular Compensation Calculator.

Located on FSWizard page and only available for milling tools it allows to calculate with of cut by stock or pilot hole diameter.

Also helical angle calculator hels converting degrees to pitch and vise-verse.

Check it out!

helical_interpolation.png

We all have manufacturer speed & feed charts and have used their recommendations.

But sometimes those charts just don't apply.

For example manufacturer charts assume you are using their endmills at a certain stickout length, flute length and at a certain depth of cut.

But in the real life you rarely match all these conditions.
Sometimes you need to use longer endmill. Sometimes your flute is longer than what manufacturer gave you speeds and feed for.

What i am trying to say is that whenever your real life conditions differ from "normal" you "need to adjust accordingly".
In fact this is what is printed below many charts.

Too bad not many sources tell you how and what to adjust.

While failure to adjust cutting parameters often leads to chatter, poor surface finish and even tool breakage, one of the biggest mistakes people do when machining is Read More