February 27, 2016, 1:21 pm by Eldar Gerfanov (Admin)
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:
February 27, 2016, 12:06 pm by Eldar Gerfanov (Admin)
Being a professional CNC Machinist myself with a good manual background I often find myself watching various machining videos and blogs.
Unlike others I do not often share somebody-else's work, I could just not walk past this one and not tell everybody how great I think this is....
This story was posted on "Russian reddit" and here is the direct translation of the author's post:
Quote:
We have a mechanic/installer at our work. He used to be a lathe machinist on a previous job and had a hobby - created a model copy of KrAZ-255B military truck. Right now he does not have time to work on it but is planning to return to it once he has more time on his hands.
Here is the mid-way result of his....art!
Lets begin with tyres. Vladimir (guy's name) decided to create the mould to make the rubber tyres himself. Here it is:
Here are the tyres he made with it. Beautiful aren't they?
He also made little differentials. Housings, gears. Everything made himself:
I notice when CNC Speeds and Feeds questions come up people often suggest my HSMAdvisor Machinist calculator. A referral by a satisfied customer is the best referral in my opinion. Thank you to everyone doing this great favor to me and my prospective users!
Other times users of HSMAdvisor question speeds and feeds it generates and instead of going to me, they ask on forums. Which is always fine, because extremely often "wrong" results mean something wrong in users expectations or the data he feeds the calculator
In the process of discussion it usually turns out that the calculation results were correct, but because user decided to use a depth of cut or tool length, larger than he should have, HSMAdvisor compensates and gives a very conservative feed rate.
October 27, 2015, 9:13 pm by Eldar Gerfanov (Admin)
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.
Code
T15 M6; (TOOL CHANGE) G0 G54 G90 X1.0 Y1.5 S1500 M3;(APPLY WORK OFFSET, MOVE TO THE FIRST POSITION, TURN ON THE SPINDLE) G43 Z2.0 H15; (APPLY TOOL LENGTH OFFSET WHILE MOVING TO 2.0" ABOVE THE PART) G0 Z0.1 M08;(MOVE TO FEED HEIGHT AND CARRY ON WITH THE PROGRAM..)
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.
October 3, 2015, 9:03 pm by Eldar Gerfanov (Admin)
Before we run any G-Code program, we need to tell the machine where our part zero is. A Part Zero is simply a bunch of numbers that offset the axis to give the machine a new coordinate point to work from.
Work Offsets is one of the most basic pieces of knowledge any machinist must-have.
Let us account for all the basic coordinate systems and definitions, available in a generic CNC machine
Machine Home and (Absolute) Machine Coordinates
Work Offset Coordinates
Tool Length Offsets
Machine Home and Machine Coordinates: G53
Machine Coordinates (or Absolute Coordinates) is the absolute and constant representation of the machine axis position. These coordinates never change between Machine Restarts and must remain such. In fact, there is often no way for an operator to adjust the Absolute Machine Axis Home position.
Machine Home is simply that magical place where all Machine Coordinates should become Zero.
To Home the Machine is to start a machine operation, that will move all Axis to their soft limit position where X, Y, and Z-axis reading will be set to zero.
Homing must be done every time you restart your machine. Without it machine does not know where is the position of its table or spindle.
When homed your machine coordinates will read X=0 Y=0 and Z=0 and it is going to look like this:
The point where Machine X and Y intersect is called Table Home Position and the one where the Machine Z-axis starts from is called Spindle Home.
Now, there is no agreement between machine tool manufacturers on where the machine home should be.
It is no secret that i am trying to make my software fit the broadest possible group of people. And while my much-respected hobby customers is a big deal for me, industrial machining is where HSMAdvisor really shines.
Recently a PracticalMachinist forum member Atomkinder posted a video of him machining something on his 1997 Fadal VMC. Here is what he had to say:
Quote:
Originally Posted by Mtndew
One thing that I just thought of, you may want to look at buying the HSM advisor ($50) for your high speed toolpaths. Doesn't even have to be high speed, but toolpaths with long engagement and small stepover are proven to run a LOT faster than hogging out the conventional way that's been done forever. Advanced CNC Speed And Feed Calculator - HSMAdvisor
I use it daily, and I can't think of a time it's let me down. I second HSMAdvisor. I own my own seat (work doesn't have one) because I like it that much.
This isn't particularly special, but it is a 1997 Fadal VMC2216 box way machine. Removed a whole tool and something like 40% of the cycle time from the second operation of this part.
November 28, 2014, 9:54 pm by Eldar Gerfanov (Admin)
A couple of days ago I helped a gentleman by answering a few questions about using HSMAdvisor Speed and Feed Calculator to machine a 310 Stainless Steel piece using HSM techniques.
Today he created a post on PracticalMachinist forums walking us through his experience. And he even took a video of the part being cut!
Quote:KROVVAX
I would also like to say thanks to zero_divide for the help he gave me with the speed/feed and after using is HSMadvisor i suggest to everyone to give it a try its really worth it.
Endorsements like this is the best thing any software developer can hope for.
I always welcome any feedback regarding my software and never mind helping anyone, whether he is a novice, experienced machinist, my customer or not.
October 12, 2013, 11:32 am by Eldar Gerfanov (Admin)
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:
Quote:
In an effort to perfect our speeds and feeds while hardmilling, this is the first try. Its not right yet, but far from a failure. I apologize for the language at the end, but I do not edit my videos. The endmill was a reground garr VRX at .353 diameter. Parameters were 750 sfm, .018 radial, .300 axial and .004 ipt. The next run will be at 650 sfm, .006 ipt using a mist sprayer. Also, any small areas will be blocked off to be ran at lower speeds to allow cooling time for the cutter. Just a note for anyone using a Mag Fadal, The E-stop button is not quick enough, use feed hold. The endmill was badly worn on the corners, but not broken, and will be resharpened and used again.
In the ensuing discussion i posted my own take on how and why HSM works
Quote:
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.
Note: Certain HSMAdvisor Licenses Include FSWizard PRO For Android for Free!! Check out our HSMAdvisor Web Storefor Details
Absolutely the best handheld CNC machinist's speed and feed calculator around. Calculate cutting conditions simply by choosing your work and tool material. No need to know any numbers. FSWizard will automatically use recommended cutting speed and chipload.
* Made by a machinist for machinists *
Improve productivity and optimize cutter life.
* Milling, Drilling, Tapping and Turning * Suggests optimum cutting depth and balances cutting parameters. * Supports Chip thinning and HSM machining. * Required Power estimation, Recommended Depth/Width of Cut for extra-long cutters. * Built in tap drill calculator to calculate not only cutting speed and feed , but also drill dia in accordance with desired thread engagement. * Drill and Tap charts for both imperial and metric systems. * Oblique Triangle Calculator * Fillet Calculator will find tangent points to a circle and two lines * Machinists Bolt Hole Circle and Line Calculators
It just does it all.
*Milling Tools: Solid EndMill, Indexed End Mill and FaceMill, Solid and Indexable drills *Drilling Tools: Jobber Drill, Hi-Performance Parabolic Drill, Spade Drill, Reamer *Turning Tools: Profiling and Grooving
Please try the Free FSWizard Lite first to confirm your device capability. Also huge thanks to those who go through the trouble and leave a review. Good reviews mean more sales and more incentive for me to further improve on this app.
FSWizard Lite and FSWizard PRO are iPhone/Android machinist calculators that do not require internet connection. PRO version has all the latest material lists and speed and feed technology.
Lite version has all the same features, but it only has tool steel, mild steel and aluminum in its material list. It still has all the tool types and tool materials found in online and standalone versions Both Lite and Pro versions have unlocked tapping data.
Lite versions have limited geometry calculators.
This app is intended not to replace but to complement my much more powerful standalone Windows application called HSMAdvisor.
HSM or High Speed Machining is becoming more and more popular each day. Many of us have seen those youtube videos where endmlls remove large amounts of material at high speeds/feeds.
While definitions of HSM may vary between tool manufacturers and even individual shops, the physics behind it remain the same.
In this article i would like to explore flat endmills.
HSM is not about ramping up your speed/feed overrides to 200% and puling out your smartphone to record another youtube-worth video.
What is HSM?
HSM is a complex of programming, machining and tooling techniques aimed at radical increase of productivity.
Programming
The cornerstone of HSM is low radial and high axial engagement of an endmill with the workpiece.
There are many CAD/CAM systems that allow you to create HSM tool-paths. Mastercam's Dynamic milling and SurfCAM's Truemill are some of them.
When radial cutter engagement with the material is smaller than the radius of the tool an interesting thing happens. Chip load- the distance the tool advances per cutter revolution per tooth- does not equal the actual chip thickness anymore. Chip thinning mainly happens at radial engagements below 30% of the diameter.
Radial Engagement vs chip thinning factor
100%
1.0
50%
1.0
30%
1.091
25%
1.212
20%
1.641
15%
2.1
10%
4.375
5%
6.882
In order to get compensated chipload you need to multiply recommended by manufacturer chipload by the chip thinning factor.
Usual Radial Engagement for HSM toolpaths however is between 5 and 15%.
Axial depth of cut varies depending on geometry, but Read More
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Originally Posted by Mtndew 
even if application does not merit that
