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.

Haloween sale is ON!

All HSMAdvisor Licenses over $90 are currently 15% off!

You can buy a 3 Year Floating License Subscription Or a Permanent License now for just $82

Life Time Subscription is only $165 And Permanent License with LifeTime updates is $186

 Cheers!

This is another video from his Productivity Series.

In there we get a quick demonstration of HSM techniques Eric is using to produce his beatiful vise.

Also my own HSMAdvisor is featured there!

Thank you Eric!

Orange Vise are produced in the USA.

Check out this website for more info http://orangevise.com

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 added Fillet Calculator to our android version.

It allsows to calculate tangent points on a circle and two lines.

All you need to specify is an angle beteen them and a radius.

Also lines intersection point can be moved around.

As a result it returns coordinates of the points and the centre of the circle.

2013-10-08_21-57-55.png

Normally i can't keep secrets and announce what i am working on.

But this time is different.

I can only tell you that i am working on a unique feature in our android version

Nobody has done anything like that. I can only tell you that i will be adding more tools for aiding manual programming on the control.

Check back soon. Like my facebook page to get the latest updates on our many projects.

The link is on the right :)

Check this video out.

The whole thing is pretty impressive, but the best part starts closer to the middle of the video. At around 3:20 you can see the size of the machine. Truly amazing.

Note: TURN YOUR VOLUME DOWN

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