At my day job I am starting to do more and more manual programming.

Which i do not realy like, but since am at it anyway i have decided to keep piling little articles about G-Code programming into this new category.
This way when i forget things again i will be able to quicly refresh my memory.

Program Start

O0001 (COMMENT OR PROGRAM NAME)

Starting safety blocks

(G20 IMPERIAL UNITS, G21-METRIC)
(G17 XY ARC PLANE, G18-XZ, G19-YZ)
(G40 CANCEL TOOL RADIUS COMPENSATION)
(G49 CANCEL TOOL LENGTH OFFSET)
(G80 CANCEL CANNED CyCLE)
(G90 ABSOLUTE POSITIONING MODE)

G20 G17 G40 G49 G80 G90

Tool Change Routine

(T14 - call 2.5" Face mill)
(M6 - Perform tool change)
(G0 - rapid feedrate)
(G55-G59 - Choose Work Offset)
(X, Y - Command a Position to move to)
(S - choose spindle speed)
(M03 - Turn spindle on Clockwise, M04 - Counter-clock wise)

T14 M6
G0 G54 G90 X{X} Y{Y} S{SPEED} M03;

Apply Tool length offset at retract height, Turn on Coolant

(G43 H14 Z2.0 - All codes must be in the same line Apply cutter length offset from record #14 to cuttent tool, move to 2.0 above work at the same time )
(M8 - Turn on Coolant)

G0 G43 H14 Z2.0 M8

Rapid tool to plunge height

G0 Z{Z_PLUNGE}

Plunge to cutting depth at plunge feedrate

G01 Z{Z_DEPTH} F{F_PLUNGE}

Make a straight cut in xy direction at cutting feedrate

G1 X{X_POS} Y{Y_POS} F{F_FEED}

Retract to plunge height at either rapid or retract feedrate

G1 Z{Z_PLUNGE}

Retract to rapid height, turn off colant

(M09 - Turn OFF coolant)

G0 Z{Z_RETRACT} M09

Retract to tool change height, turn off spindle

(G28 G91 Z0 - all coes must be in the same line, move Z axis to HOME POSITION through a reference point)
(G91 Z0 - Causes reference point to be the current location, thus sending axis straight up )
(M05 - Turn off spindle)

G0 G28 G91 Z0 M05

Perform Next tool change or end program

M30(end program)

Another week another update!

A few days ago a topic popped up in CNCZone's BobCad-CAM forums regarding why speeds and feeds in above mentioned BobCAM were so crazy and unworkable.

Users were complaining and raving about such a "simple" thing like a good speed/feed calculator being missing from there.

This is actually a trend in pretty much any other CAM software package.

They sell tool to create toolpaths.
Many give tools to create 2D geometry and even real solids.

But very few CAM packages offer anything that even remotely resembles working starting cutting parameters.

It does seem bizarre and strange. But every CAM program "knows" type of material being worked on. It knows type of tool, its diameter and length.
It even knows flute length, cutting depth, width, ramp angle... pretty much everything.

But given all that they are unable to combine all this data and produce Speed and Feed that would not either break the cutter or melt it into the work-piece!

Anyway. Back to the topic.

Someone on that forum thread mentioned my old FSWizard.
It sparked quite a lot of interest, and i popped in and dropped a link to the latest version of HSMAdvisor, so that they actually try and see what a good calc can do.

As a result i have received a ton of emails filled with suggestions and thank-yous.

Apparently many did not even know anything about it and were surprised how well it worked for them.
One guy who just bought a license even said that his copy already paid for itself several times over within the first couple of days of using it!

To thank for enthusiasm, i quickly implemented some of those suggestions and i am now releasing them in this version 0.710

New thing are

• Adjustable font size and style. (in Settings) Allows to adjust global application font.
• Adjustable default values for Speed&Feed Overrides, Tool Productivity, Deflection and Torque Limits. (in Settings) You can now set values to which overrides reset by default.
• New Plunge Feedrate field shows up for milling tools.
  Non-Center cutting tools like Indexed endmills etc. will have plunge feed equal Zero.

Thanks everybody for support and suggestions!

As usual you can download the latest release on the Download page.

Happy New Year !

First of all i would like to thank everybody for their continuing support and feedback - without you my work would not be this rewarding and fun.
This holiday season sale has been a success and it is only reassuring me that i am moving in the right direction regarding development of this software.

Also 20 days after the very first release of FSWizard for iOS, sales for it and the Android versions have been going very strong. Which means i will be putting even more effort into improving the mobile versions as well.

New things in HSMAdvisor 0.701:

• Cut and Form taps have been added.
• Boring Bar has been added to the tool type list
• Scallop calculator has been added for ballnose type endmills

Updated and fixed things:

• Effective diameter for tapered endmills (like V-Bits) has been fixed
• Deflection model for endmills has been improved
• BallNose endmills are now considered slotting (floor milling) only when their WOC is set equal to the diameter of the tool.
  When WOC is not equal to the tip Dia, it is presumed the cutter is milling the wall rather than the floor
• Some Tool Geometry fields have been moved to a new tab.

Again after this release i will shift my attention back to mobile versions of FSWizard

Tapping Tool Type BallNose Mill Scallop Calc

Since surface milling is more than half of what i do for a living, I decided to share some of my tips on that topic.

Generally you want to create a continuous toolpath that does not change directions too often.

Changing directions slows the machine down and reduction in feedrate affects deflection of the cutter. Different deflection means you get gouge marks on your surfaces.

When you have a long narrow piece its better to go along the long side to save on time and machine wear.
Also going along the longest side reduces the number of direction changes you will have to make

When milling cavities you need to first rough, then semi-finish then finish.

Leave 15 thou after roughing, 3 thou after semi-finishing and finish to zero. All with progressively smaller tools.
5 thou stepover will give you very good finish on most ball mills
3-5 thou chiploads are very common for surface finishing.

Ball mill will always give bad finish on shallow areas- the center is not cutting, but dragging around.
Also straight portion of the flute acts as a wiper and reduces scallop that the ball portion creates.

This is why going from top to bottom is safer and yields better surface finish.

The closer the wall taper angle to the taper of the flutes the better finish you will get.

There is another reason for always trying to go from top to bottom.

When taking material top to bottom you engage stock closer to the tip of the tool.

It makes cut more stable. It is more safe because you are less likely to bury the tool in stock unexpectedly.
Do not go from climb milling to conventional UNLESS you need to save some rapid time.
Pick up only climb milling and you are good to go.
Changing from climb to conventional will cause tool to deflect away from the work on climb and into the work during conventional pass. You will see zebra marks all over your surfaces.

In this release I have added CAD/CAM integration.

Please read the latest tutorial in HSMAdvisor Tutorials section here
This is a pretty Unique way of doing it.

It is still in the beta-mode.
But it is fully functional. I have tested it on MasterCAM and SurfCAM with great results.
While some functionality is not supported well on all cadcam packages, it is still much better than nothing.

Please send me your feedback on how it works with your CADCAM package.

I have also added a list of recently used materials.

Now material list will have 6 recently used items at the very top of it.
Later on i will allow user to enter whatever number of recent items he wants to see there. But for now its just 6.

New Computer ID and New License keys

Starting from this release i have changed how Computer ID keys are generated.
This was done to fix problems some of the users experienced when they added or removed additional hardware on their computers.

New Computer ID's mean License keys have been changed for all users as well.
Not to worry though, License keys will be automatically updated for all of our users, so no action from their side is required.

If you have active license. You will get a message telling you what happened and your license file will be updated automatically.

Some bugs got fixed as well.

All of them were pretty minor, nothing to write home about.

Material definitions got updated as well.

Added several materials, updated speeds and feeds for tool steels and stainless steels.

I still have to add some of the previously requested materials (like Weldox Graphite, etc) to the list.
And i am planning to add it in the next release.

Chiploads for micro-milling were changed as well.

Chiploads for micro-endmills (below 1/16 dia) were reduced significantly.

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.

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.

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 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.

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