Jump to content

Welcome to eMastercam

Register now to participate in the forums, access the download area, buy Mastercam training materials, post processors and more. This message will be removed once you have signed in.

Use your display name or email address to sign in:

5 Axis Gantry Programming


Recommended Posts

Hello eM,

Besides the obvious size and shape of the machines, is there anything fundamentally different about 5-axis gantry programming, in relation to a conventional 5-axis machines?

Specifically, picking up work offsets and determining which planes to work from.

Most of the newer machines have TCP built into them, including the gantries.

In theory this means the work offsets and planes can be established like a regular 3 axis part.

It appears that most of the  gantry machines are head/head configurations, which for some, makes it harder to visualize where the center rotation point of the tool path is coming from.

Link to comment
Share on other sites
58 minutes ago, mayu said:

makes it harder to visualize where the center rotation point of the tool path is coming from.

You just program it from wherever you want your zero to be.  No need to visualize cor unless you need to worry about making a smooth resulting kinematic toolpath.  Understanding the basic offsets of the kinematics of your machine help here. 

  • Thanks 1
Link to comment
Share on other sites

Like Husker said not much different unless it is a limited Primary Axis of travel then it gets interesting. I have programmed many different bridge type machines and the stronger ones have a limited primary rotation axis. The weaker machines have a full travel primary rotation axis. What that means is you can spin it to infinity like a turn in type machine or even most 4 Axis machines. That means some times you may need to pre wind you head to do some large travels. The other issue is large parts may mean you have to dance around the part. Linking moves and understanding the mi and mr switches in the post that control home movements becomes important. The next thing will be risers if you need to machine at 90 degrees to your parts. Draw you a travel limit wireframes box so you can use it to help you visualize it when setting up your parts in your ,achi e space and what and here it will be on the machine. Next normal progression will be using a Right Angle head on your 5th Axis machining center. Don’t let it scare you and with the right post not to bad. Approach it like anything take the time to learn it get a good verification model and software. 

Edited by crazy^millman
Correct my to mr
  • Like 1
Link to comment
Share on other sites

Excellent points - absolutely fascinating

Yeah the c-axis lathes do that - spin to infinity -  really annoying.

So it appears that the post is really the secret sauce.

Not familiar with those mi and my switches  you mentioned - looks like it's time to study them.

Brilliant idea on the travel limit wireframe box.

A right angle head is just over the top.

Link to comment
Share on other sites
9 hours ago, mayu said:

Excellent points - absolutely fascinating

Yeah the c-axis lathes do that - spin to infinity -  really annoying.

So it appears that the post is really the secret sauce.

Not familiar with those mi and my switches  you mentioned - looks like it's time to study them.

Brilliant idea on the travel limit wireframe box.

A right angle head is just over the top.

Sorry on the my I mistyped that should be an mr.

These are called Misc Integers and Reals that a post looks at in an machining operation in everything except MT. They are switches and they give direction to the post to do certain behaviors. Each post builder makes them their own and each one has very powerful functions depending on how the post is built. I have trained many programmers who have never once looked at them. They wonder why the machine goes home between each 5 Axis move. Yes you have told it to. No I didn't!!! Okay let me rephrase that. You didn't change the switch that controls that behavior and by default sending it home is safe. Change the switch that controls that and now you have told it not to and it will not. We get into old school Mill/Turn without MT and we have Lathe Switches and Mill Switches. Each has a specific function and if you not sure then go back to your post builder and get an expliantion of what, how, where and why they work. Keep asking question and keep learning all you can.  

  • Like 1
Link to comment
Share on other sites

Thank you so much for the clarification.

These switches need to be mastered.

Haha returning home between each move on a big gantry would definitely be embarrassing.

Agreed - keep asking questions as much as possible. Our reseller is usually not busy and responds pretty much immediately. People aren't utilizing him/her as a resource.

So on this gantry below, the primary axis of travel (spinning head) would be the B axis, since it rotates around the X (assuming the operator is staring perpendicular at X)?

 

5_axis_gantry_0.png

Link to comment
Share on other sites

Some Head-Head machines are BC, AC, BA and some are AB really comes down to how they have defined it internally. Looking at yes I would think it is a CA, With C spinning around Z and A spinning around X but until I got sample code from the builder I could not be sure. 

That is a 5 Axis machine and your statement XYZ-ABC defines a 6 Axis machine. 

XYZ-AB

XYZ-AB

XYZ-BA

XYZ-BC

XYZ-CA

XYZ-CB

I have seen all 6 different configurations over the years on Head-Head machines. 

  • Like 1
Link to comment
Share on other sites
1 hour ago, mayu said:

Sorry typo - primary axis of travel A not B - because it spins around X?

XYZ - ABC

Typically, the Primary / Secondary names refer to the Rotary and Tilt Axes.

Any of the two rotaries can be assigned "primary", and the other assigned "secondary".

Really, this just comes down to the math calculations inside the Post Processor.

I will always assign the rotary axis with "the most rotary travel", to the Primary.

On that Gantry in your picture, the Primary should be "C" (Rotates about the Machine Z-Axis).

The Secondary would be A or B, depending on:

  1. Which machine axis the rotary rotates about, and
  2. which Address Letter the Machine Tool Builder assigned to that particular axis.

For example, Haas Machines always used to assign A and B to the Rotary Axis Addresses, even though they are not rotating about X and Y Axes.

Once they developed the Haas UMC-750, they ran into problems with TCP working correctly, so they had to assign the standard ANSI Axis Designations to the Rotary Addresses.

I would recommend asking your Reseller for a copy of the Generic Fanuc 5X Mill Post PDF File. This file covers the method of setting up the Post, and also describes how to use the Misc Integers and Real Numbers to control the Post output. I used this document as the "base" for a 5-Axis Post Class I taught. We took the Gen Fan 5X Mill Post, and configured it for a Trunnion Machine, and then took a copy of the same Post, and configured it for a Gantry Machine. I also showed how the "Unwind" function works, and how to use the Approach and Retract Vectors in combination with MI7 and MI8 to control the Post.

You should be aware that the Generic Fanuc 5X Mill Post (by Default), is not setup to handle the "modern 5-Axis Machine Functions", which make setting up the machine easy.

The Gen Fan 5X Mill Post is setup to output the "Pivot Point" of the CNC Machine, for a Gantry Mill. This means you must calculate (exactly) the Tool Gauge Length, and the Pivot Length of your 5-Axis Mill, and you must supply these two numbers accurately to the Post Processor, to get good 5-Axis Code.

This is really the "Old School" method of running a 5-Axis machine, and it worked for many years with great success, but also has many pitfalls. Foremost, is the fact that you must accurately measure every tool, before you Post Process the NC Code. If you happen to have a Tool Offset Length that changes, then you must "re-post" the NC Code for that new tool length.

For Gantries, the can lead to many issues, as you might have guessed.

On a Gantry Machine without TCP or TWP (we'll get to those definitions in a minute), you are limited in the types of cuts you can do. Sure, you can do a full 5-Axis Swarf cut, relatively easily using Mastercam and an accurate tool length. However, you are limited to 3-Axis Compensation methods. This means you can only use standard TLO (G43/G44/G49), and you can only use Cutter Radius Compensation on the 3 orthogonal machine planes that exist on a Fanuc. (G17, G19, G18)

If you have an "Angled hole", you must drill it point-to-point with G01 moves. You can't "tap a hole" on anything except the 3 Planes.

To overcome this obstacle, they invented Tilted Work Planes. (TWP) This is G68.2 on a Fanuc Control.

The TWP command allows you to do two things:

  1. Move the origin of the new plane, relative to the Current Work Offset Location.
  2. Tilt the "working plane" (G17), to new Rotary Angles.

TWP allows you to use:

  • G43 - Relative to this "tilted plane"
  • G41/G42/G40 - Relative to this "tilted plane"
  • Canned Drill Cycles - Tapping and Drilling on the Tilted Plane.

You don't necessarily "have to move the XYZ origin", when using TWP. However, I think this is one of the great options of this feature. For example, I can give a new XYZ Origin, for the "face" of the plane I'm about to drill. This makes it so my Canned Drill Cycle Z Values are easy to understand. The "Z0." is now the tilted face of the part, so my Z Depth for the cycle could be something like Z-.855. If I want to drill the hole a little deeper, I can just modify the code easily at the machine. So much easier than a "R plane of 4.9226, and a Z Depth of 4.0721. (Example numbers, if I had not moved the XYZ origin with the G68.2 command.)

Again, the Gen Fan 5X Mill Post is not setup for TWP or TCP  or WSEC or DWO, by default. If you are familiar with the Post, and Post Editing, you can add these functions to the Gen Fan 5X Mill Post without too much trouble.

 

  • Like 2
Link to comment
Share on other sites

The Primary/Secondary designation also changes, depending on the Kinematics of the machine.

Remember; a Trunnion rotates the Part, and a Gantry rotates the Tool.

So between the two types; the calculations are reversed.

There is a lot more to it of course. Reading that Generic Fanuc 5X Post PDF Guide might help you to understand the complexity that is built into the Post. There are so many different features to understand; how to set the default values, but also how to use the controls that are built into the Post to get the output you need. Ron alluded to this with talking about a "Right Angle Head". Although he used a 3rd Part Post Builder, the Generic Fanuc 5X Mill Post also has "Right Angle Head" options built into it. You can drive a RAH, mounted to a Gantry or to a Trunnion-Type machine, by using MI2$, the OAL Tool Length, and MI10$.

  • Like 1
Link to comment
Share on other sites
On 10/9/2020 at 9:48 AM, crazy^millman said:

Some Head-Head machines are BC, AC, BA and some are AB really comes down to how they have defined it internally. Looking at yes I would think it is a CA, With C spinning around Z and A spinning around X but until I got sample code from the builder I could not be sure.

Finally got around to seeing the machine in question, and even got to play with it a little bit. Yes it is a XYZ - BC configuration, and does not wind to infinity.

It was not so intimidating - not at all.

You were spot-on about the need for risers. It also appears to be a delicate balance between risers and Z clearance.

What was also interesting was the square grid pattern on the table (50mm or 80mm). At first glance I don't care for it, and would prefer to build some custom blocks or sub-plates to mount parts on.

But this is just the initial thought process - it will likely evolve.

Also your wireframe box tip for visualizing travel-limits will be extremely helpful.

Thanks again

  • Like 1
Link to comment
Share on other sites

Thank you Colin for the above-and-beyond response - highly insightful.

Yes I will absolutely obtain the Generic Fanuc 5X Post PDF Guide immediately.

So it turns out that the machine in question does have TCP and TWP so this will spare us many headaches.

If I'm understanding you correctly, since the generic 5X post is not setup for TCP and TWP, we have to find the intersection of the XYZ axes, just like in the old trunion days, and insert these values into the appropriate post variables?

Also is the TWP activated when TCP is activated? For example on a Haas machine, TCP is activated with G243, Fanuc G43.4, etc. Does that automatically activate TWP? This is one thing I forgot to ask.

Take care

 

  • Like 1
Link to comment
Share on other sites
21 hours ago, mayu said:

Also is the TWP activated when TCP is activated? For example on a Haas machine, TCP is activated with G243, Fanuc G43.4, etc. Does that automatically activate TWP?

TWP is activated independently and before you activate TCP. Usually you do not run them together. TWP is not a rotary type function. It is a 3+2 type function. TCP is the rotary type function.

On a FANUC, you would activate things in the following manner;

N5T5M06(1/32 Stub LOC Ball E/M - BBT40-MEGAER16-90NL)
G49G53Z0.0T6
M08
G131F1(ACTIVATE HIGH SPEED LOOK AHEAD FOR MATSUURA)
(Flow ISO-TC39SC2-N2185 Feature - Side 1)
S20000M03
M132(UNCLAMP A AND C AXES)
G00G90G54A-29.755C-147.24
G54.4 P1(ACTIVATE WSEC)
G68.2 X0.0 Y0.0 Z0.0 I-147.24 J-29.755 K0.0(ACTIVATE TWP)
G53.1(ACTIVATE SPINDLE DIRECTION)
X0.5398Y0.4636
G69(CANCEL TWP)
G43.4Z0.5H#517(ACTIVATE TWP)
X0.0994Y-1.152Z0.8547

G130(CANCEL HIGH SPEED MODE)
G00G90G49(CANCEL TCP)
G53Z0.0(MACHINE HOME Z-AXIS)
G54.4 P0(CANCEL WSEC)

 

Link to comment
Share on other sites
10 hours ago, cncappsjames said:

TWP is activated independently and before you activate TCP. Usually you do not run them together. TWP is not a rotary type function. It is a 3+2 type function. TCP is the rotary type function.

On a FANUC, you would activate things in the following manner;

N5T5M06(1/32 Stub LOC Ball E/M - BBT40-MEGAER16-90NL)
G49G53Z0.0T6
M08
G131F1(ACTIVATE HIGH SPEED LOOK AHEAD FOR MATSUURA)
(Flow ISO-TC39SC2-N2185 Feature - Side 1)
S20000M03
M132(UNCLAMP A AND C AXES)
G00G90G54A-29.755C-147.24
G54.4 P1(ACTIVATE WSEC)
G68.2 X0.0 Y0.0 Z0.0 I-147.24 J-29.755 K0.0(ACTIVATE TWP)
G53.1(ACTIVATE SPINDLE DIRECTION)
X0.5398Y0.4636
G69(CANCEL TWP)
G43.4Z0.5H#517(ACTIVATE TWP)
X0.0994Y-1.152Z0.8547

G130(CANCEL HIGH SPEED MODE)
G00G90G49(CANCEL TCP)
G53Z0.0(MACHINE HOME Z-AXIS)
G54.4 P0(CANCEL WSEC)

 

James you can activate G43.4 directly on a lot of Fanuc machines by just calling it without needed to position it with G68.2 . Here are 4 different 5 Axis Fanuc machines. The last one is the V table on a dual table Router Machine.

(T35  - HELICAL - 47465 - END MILL FOR ALUMINUM -  VARIABLE PITCH - 3 FLUTE X 40° HELIX X 1.0000 DIA X 1.2500 LOC X 6.0000 REAC - H35  - D35  - D1.0000" - R0.5000")
N1 G00 G17 G49 G69 G40 G80 G90
N2 G53 Z0.
N3 M62 M64
N4 A0. C0.

N5 (APPROACH MOVE MIDDLE SECTION START T35)
(GET 5 AXIS HEAD)
G321 A4
(NEXT TOOL =  T35 )
M98 P7003
 (HELICAL - 47465 - END MILL FOR ALUMINUM -  VARIABLE PITCH - 3 FLUTE X 40° HELIX X 1.0000 DIA X 1.2500 LOC X 6.0000 REAC)
N6 G59 G17 G90
N7 M62 M64
N8 G00 C-185.994
N9 A-101.
N10 G01 G94 X2.6251 Y21.8428 S5000 M03 F500.
N11 G43.4 H35 X2.6251 Y21.8428 Z44.8755
N12 Z44.7755 F120.
N13 Z33.6885
N14 (MACHINE ID MIDDLE SECTION #1)
N15 M08
N16 X2.5268 Y21.8544 Z33.7565 A-92.188 C-186. F200.
N17 X3.1871 Y27.5655
N18 X3.2498 Y28.1618 Z33.7794 A-92.187
N19 X3.2915 Y28.5593 Z33.7947 F120.
N20 Y28.572 Z33.795
T1   - 3" FACE MILL         - H1   - D1   - D3.0000")
G00 G17 G20 G40 G49 G69 G80 G90
G00 G91 G28 Z0.
M26
M28
G28 B0. C0.
(LINK MOVE START)
G00 G91 G28 X0.
T1 M06 (3" FACE MILL)
G54
G00 G17 G90 X19.0663 Y17.9603 S1200 M03
G43.4 H1 Z6.
G00 G90 B0. C0.
X19.0663 Y17.9603 Z5.706
M08
G01 X19.0669 Z5.6727 B2.113 F15.
X19.0675 Z5.6394 B4.229
X19.0682 Z5.606 B6.341
X19.0688 Z5.5727 B8.90
(T23  - 3/4 FLAT ENDMILL 1.25 FLUTE LENGH 2.0 OUT - H23  - D23  - D0.7500")
N1 G00 G17 G40 G80 G90
N2 G91 G28 Z0.
N3 M11
N4 M79
N5 G90 A0. B0.

N6N6 (OPERATION NO - 23)
N7 (3/4 FLAT ENDMILL 1.25 FLUTE LENGH 2.0 OUT)
N8 T23
N9 M06
N10 M68
N11 G54 G17 G90
N12 S7800 M03
N13 M10
N14 M78
N15 G00 G43.4 H23 X-1.176 Y-1.4514 Z3.4117 A-10.545 B10.729
N16 M11
N17 M79
N18 G94 G01 X-1.2858 Y-1.5612 Z2.8321 F394.
N19 X-1.359 Y-1.6344 Z2.4458 F150.
N20 X-1.3546 Y-1.6102 Z2.439 F20.
N21 X-1.3529 Y-1.5811 Z2.4317
N22 X-1.3553 Y-1.5519 Z2.425
N23 X-1.3615 Y-1.5232 Z2.4191
N24 X-1.3715 Y-1.4953 Z2.4141
N25 X-1.3851 Y-1.4689 Z2.41
N26 X-1.4021 Y-1.4443 Z2.407
N27 X-1.4218 Y-1.4218 Z2.4048
N28 X-1.5364 Y-1.3078 Z2.403 A-9.492 B11.758 F40.
N29 X-1.6429 Y-1.2018 Z2.4019 A-8.512 B12.708
N1 G00 G20 G40 G49 G80 G90 G94 G98
N2 G91 G28 Z0.
N3 G91 G28 B0. C0.
N4 G28 X0. V0.
N5 M15
N6 M00
N7 (TOP BACK EDGE)
N8 T3 (3.1" DIA SAW, .100" WIDE, 4.4" OOH)
N9 G00 G54 G17 G90
N10 S13000 M13
N11 G49
N12 G00 B-14.425 C-51.018
N13 G00 X-8.1925 V97.7326
N14 G43.4 H3
N15 X-8.1925 V97.7326
N16 Z2.0007
N17 M78
N18 X-8.1141 V97.6358 Z1.5165
N19 G94 G01 X-8.0358 V97.539 Z1.0323 F130.
N20 X-8.6449 V98.2919 Z.7831
N21 X-8.7229 V98.2289 Z.7835 B-14.442 C-51.032
N22 X-8.8007 V98.1661 Z.7839 B-14.459 C-51.035
N23 X-8.8784 V98.1034 Z.7843 B-14.476 C-51.029

 

Link to comment
Share on other sites
1 hour ago, cncappsjames said:

I use it strictly for a safe pre-position move.

One key to turning on G43.4 before, or making a preposition move is the parameter that controls if TCP is turned on before movement or at the end of the block.  Either way, I do believe it lands a the same spot, but it certainly effects the machine motion getting there, especially if there is rotary movement involved.  If it activates at the end of the block G43.4 can be a very safe or very dangerous means of doing a rapid pre-position.  It all a bout awareness of how the machine moves around.  I prefer to have G43.4 active at the start of the block on a HH machine, but would think it might be better the other way around on a table/table.  H/T, probably active before.

Link to comment
Share on other sites
3 hours ago, crazy^millman said:

Tell em about ti and seems I always find the machines that are not setup correctly and have to chase things down. :wallbash:

The worst is machine tool builders that don't set these parameters the same from serial # 50 -> 51, one day to the next on the production line for the same machine model and option spec.

  • Like 1
Link to comment
Share on other sites
On 10/17/2020 at 10:22 AM, huskermcdoogle said:

The worst is machine tool builders that don't set these parameters the same from serial # 50 -> 51, one day to the next on the production line for the same machine model and option spec.

Understanding the business the way I do, believe it or not, there are legitimate reasons that could be the case where two back to back machines could be configured differently. MC1 is a factory pre-order, configured per the sales order. MC2 on the line was set to be a "stock" machine. Configured in a basic manner. Happens all the time. Dealers and builders shift machine orders all the time for a variety of reasons. 

Now, "should" a machine tool builder configure all 5-Axis machines the same? That is a legitimate question. A LOT of questions would need to be answered first.

JM2CFWIW 

  • Like 1
Link to comment
Share on other sites
20 hours ago, cncappsjames said:

Understanding the business the way I do, believe it or not, there are legitimate reasons that could be the case where two back to back machines could be configured differently. MC1 is a factory pre-order, configured per the sales order. MC2 on the line was set to be a "stock" machine. Configured in a basic manner. Happens all the time. Dealers and builders shift machine orders all the time for a variety of reasons. 

Now, "should" a machine tool builder configure all 5-Axis machines the same? That is a legitimate question. A LOT of questions would need to be answered first.

JM2CFWIW 

Very good insight.  I had a good understanding of that prior to your wise words, but you summed it up very well!  

What frustrates me mostly is the lack of standards from one product line to the next, even within the same builder.  Forget about the dealer being able to successfully get a machine up to par (if options were not configured properly) without tons and tons of post sales support, whether it be from applications, service, or the MTB.  I have seen it take years to get things fully squared away due to machines having been "reconfigured" at the factory last minute to make a sale.

Link to comment
Share on other sites
42 minutes ago, huskermcdoogle said:

What frustrates me mostly is the lack of standards from one product line to the next, even within the same builder.  ...  I have seen it take years to get things fully squared away ....

That's a VERY valid AND fair criticism.

On the Applications Engineer side, you've got every skill set from "...I know how to turn on a machine and do and teach basic functions..." up through I can take a dysfunctional control , make it perform as expected or better, AND teach someone else how to do it" and everything in between. The VAST majority being in the 1st camp.

I found out early on when I worked for Mori there's two basic levels of understanding regarding CNC machines. 1) The "Operator" Level; meaning I understand the control and machine from an operator, programmer and setup standpoint and 2) The Engineer Level; meaning, I have a problem with a function on my machine and I know how to troubleshoot and solve the problem.

My personal goal has always been to be on the latter side as opposed to the former side. Me, I'm still learning every day so... at least I'm on the path :D . I feel like I have a long way to go to be THE MAN. The reality for that level of knowledge and expertise is that it has to kind of be a personal mission type deal. IOW, when a customer or a competitor says "... you can't do that...", or such and such "... is impossible...", you have to want to be the "... oh, yeah... watch this..." kind of guy. There really are FEW that are willing to put in the time and effort to be THAT guy. They are your 6 figure guys. The top end of the talent pool if you will. They are few and far between unfortunately. Because they are so few and far between, it often makes machine tools look unnecessarily bad.

JM2CFWIW

  • Like 1
Link to comment
Share on other sites
9 minutes ago, cncappsjames said:

My personal goal has always been to be on the latter side as opposed to the former side. Me, I'm still learning every day so... at least I'm on the path :D . I feel like I have a long way to go to be THE MAN. The reality for that level of knowledge and expertise is that it has to kind of be a personal mission type deal. IOW, when a customer or a competitor says "... you can't do that...", or such and such "... is impossible...", you have to want to be the "... oh, yeah... watch this..." kind of guy. There really are FEW that are willing to put in the time and effort to be THAT guy. They are your 6 figure guys. The top end of the talent pool if you will. They are few and far between unfortunately. Because they are so few and far between, it often makes machine tools look unnecessarily bad.

James,

This was also a great read....  You can't train the above, it's a personal desire.  The only thing that will help those of use with this desire is the opportunity to gain the EXPERIENCE with that function or type of problem that we are so well suited to solve.

I love it when a customer tells us there is no way to make something in a certain amount of time with one spindle and a stable process.  It becomes my #1 problem to solve and after many hours of my own time (plus company time), I usually come out ahead.  The only thing that makes it happen is the desire to learn, which usually through brute force and time we will!

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.

Join us!

eMastercam - your online source for all things Mastercam.

Together, we are the strongest Mastercam community on the web with over 56,000 members, and our online store offers a wide selection of training materials for all applications and skill levels.

Follow us

×
×
  • Create New...