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vector wiggle 5 axis surface machining

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Newbie

vector wiggle 5 axis surface machining

Performing a 5 axis cutline machining and trying to smooth out the vector tool axis changes. The interpolation between 2 points is too jumpy or has wiggle. I would like to improve this

The machining has a high quality requirement and I have very small scallop and tight tolerance on the sequence. Does this also impact the vector movements?

For my axis def I am using points of srf, location, axis. I have spaced these points out evenly around my cutlines. . Is there a best practice for the amount of points to use?

How about specific parameters that control the vector, such as ANGULAR_TOLERANCE what is good setting here? Or does not apply.

All thoughts and comments appreciated. Thanks

3 REPLIES 3
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RE: vector wiggle 5 axis surface machining

Eric,

Although other CAM softwares in the market already supports toolpath discretizationfor a long time, Pro/NC will only support it from WF5.0 onwards.

What you can do to reduce such issues is to define the LINTOL parameter for these sequenceswith a very small values, as 0.001 or 0.0001 (I use these values in mm - Please convert them to inches if necessary) - You can make some tests to find the ideal value for your applications.

Asmall value in LINTOL willforce Pro/NC to generate extra motions which may help youwith these issues.The PP must will also handle with the linearization differently, and this may help you substancially.

From Pro/NC help:

"LINTOL

Allows you to specify the linear tolerance interpolation used by post-processor, for multi-axis milling and Mill/Turn rotary linearization. Outputs the "LINTOL / r" statement at the beginning of the CL file. The default LINTOL is a dash (-), in which case the LINTOL statement will not be output. "

If you are experiencing serious problems, you may contact Fred Nemecek at Austin NC (www.austinnc.com) orKent Hanson at Post-Pro (http://post-pro.com/aboutus.aspx)

Both them are very experienced guys regarding Pro/NC posts and I´m sure that they may help you out.

Regards,

Daniel Santos - Sr. NC Programmer / CAM Support

Liebherr Aerospace Brasil

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RE: vector wiggle 5 axis surface machining

WF5.0 Enhancement:

Control for 5-Axis Surfacing Improved: http://www.ptc.com/appserver/wcms/relnotes/note.jsp?&im_dbkey=78491&icg_dbkey=826

Regards,

Daniel Santos - Sr. NC Programmer / CAM Support

Liebherr Aerospace Brasil

Highlighted

RE: vector wiggle 5 axis surface machining

Eric,
I almost missed it: There are some further tricks that may help you with this issue:
Pro/NC allows you to define the number of digits of your CLData in order to minimizerounding issues that may arise during post-processing. If you did not do it already,it may worth a try to set the following config.pro options as shown below :
mfg_xyz_num_digits = 8
mfg_ijk_num_digits = 8
If you use 5 axis machining very often, you can also create site files to use small values for LINTOL by default. This is also valid for machining tolerance of finishing toolpaths.
Another idea is to use absolute accuracyin you models... (Cons: Regeneration takes longer - Bigger file sizes / Pros: Better dimensional accuracy -In some cases, when using 2D milling based on surfaces, (Like Profile / Trajectory) shorter NC programs for contouring because Pro/NC will create more arcs instead of point-to-point toolpaths... It will see the curvature of the surfaces more precisely... simply put...
To use absolute accuracy, set the option below in your config.pro

enable_absolute_accuracy= yes

Last but not least, it is important to stress that none of these tips alone are really effective. The key is to use all them together.

A quick start for better surface finishes and dimensional accuracy and better GCode:

* Get a good post processor - If your control offers HSM functionality, it is important to issue the proper code in the GCode to take advantage of this capabilities.

* Work with absolute accuracy whenever you can - I personally use to set it as 0.001mm - This is the smaller increment I can program on my controls. In Inch I would use 0.0001" as most of controlsworks with this accuracy level.

* If working in multiaxis mode, use LINTOL. I use to set it as my absolute accuracy/maching tolerance.

* Use small tolerance values in general, unless you are roughing. This is specially important for 2D strategies based on surfaces (Profile milling / Trajectory using surfaces instead of chains) - I use to set it as my absolute accuracy as well. - Pro/NC will generatearcs whenever is possible...

* And of course, get WF5.0 as soon as it becomes reliable andan option. Then you can use toolpath discretization...

HTH

In Reply to Daniel Santos:

WF5.0 Enhancement:

Control for 5-Axis Surfacing Improved: http://www.ptc.com/appserver/wcms/relnotes/note.jsp?&im_dbkey=78491&icg_dbkey=826

Regards,

Daniel Santos - Sr. NC Programmer / CAM Support

Liebherr Aerospace Brasil



Regards,

Daniel Santos - Sr. NC Programmer / CAM Support

Liebherr Aerospace Brasil

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