non cutting move update

Non-Cutting-Moves Frequently Asked Questions & Changes since NX 5.0

Edwin Gasparraj and Tim Fithian,March 07, 2008

Some important conceptsFrequently Asked QuestionsWhat has changed since 5.0?Migration issues and remedies.ENV Variables What is still not working? Items in progress.Priorities for NX7Feedback

Siemens PLM Confidential

For development reference…

Group 1 > 2.5x operations such as planar mill, face mill, planar_profile, cavity mill and Z Level.

Group 2 > Fixed Axis surface Contouring operations.

Group 3 > Variable Axis Surface Contouring operations.


Feed-rate Vs Move-type (move_types.prt)

Planar Mill, Planar Profile, Face Mill, Cavity Mill, ZL

Fixed and Variable Axis Surface Contouring


Move-types

Cut moves are tool path segments that cut the part. First-cut moves are tool path segments that are embedded (violate the given step-over by

step-over limit.) Step-over moves connect two adjacent Cuts in a pattern within a region/level. Engage moves are attached to the beginning of Cut. Retract moves are attached to the ends of Cut. Approach moves bring the tool from Clearance to Engage. Departure moves take the tool from Retract to Clearance. Departure and Approach moves are connected by,

o Rapid moves (type) at or above the clearance plane/geometry.o Traverse moves below the clearance plane. (Example, Direct transfer, lowest Z transfer,

Previous Plane transfer, etc.) o From and Gohome moves are also Rapid move-types.o Start and Return moves are Traverse move-types.o Traverse moves at the Cut Level are marked as step-over moves.


Feed-rate Vs Move-type (continued.) Move types are attributes/tags attached to tool path segments. Feed-rate is applied to tool path segments based on move-types. When 0.0 is specified as feed-rate for moves other than ‘Cut’,

o Engage inherits Cut feed-rateo Retract inherits Cut feed-rate (See exceptions in the

next page.)o First-cut inherits Cut feed-rateo Step-over inherits Cut feed-rateo Rapid gets G0o Approach gets G0o Traversal gets G0o Departure gets G0o In the display, all G0 moves are shown in dashed-lines.o Users can override inheritance by keying in a required feed-rate.)

To make all operations follow similar move-types,o Return move-type is removed from planar mill, planar profile, cavity mill, Face mill and Z

Level operations.o Departure move is introduced in planar mill, planar profile, cavity mill, Face mill and Z

Level operations. (Departure Event handler in Post Builder will be introduced in NX6.)o Traverse move is introduced in all fixed and variable axis surface contouring operations.


Retract Moves. Before NX 5.0.3, some retract moves were marked as CUT and some as RAPID.

o Circular retracts were always marked as CUT.o Linear retracts in some operations if they align with the cut plane were marked as RAPID

Starting NX 5.0.3, retracts are retracts, with legacy/non-milling exceptions.


The following operations will assign G0 to retract moves when the retract feed-rate is set to 0.0.

All Legacy Lathe operationsDrive Curve LatheGSSM(Sequential Milling)Hole MakingHole MillingAll Turning

RETRACT/ENGAGE – “none” type added to all groups. Allows users to get approach and departure directly to cut, bypassing engage/retracts.

Smoothing between passes.Work-around for patterns where smoothing is not available in patterns.Set pattern to zig-zag-with-lifts. engage, retract, direct transfer, NCM smoothing.Works for linear engages. For arc engages, you need to add a linear extension. (Fixed in 6.0) (Fender_scan.prt)


Minimum Clearance for closed engage controls ramp off walls during retract.Part safe clearance. (ncm1.prt, types_am.prt)Part Safe clearance affects where the engage feed-rate starts. If approach/departure is closer to the part wall by part safe clearance, the portion close to the part by part safe clearance is marked with engage/retract feed-rate. (Starting in NX5.)


By default, all NCM moves are gouge-checked.

Group 1 has gouge checking On/Off. This was only available in group 2 and 3. Need for this toggle is minimal.Made available to make old migration parts work.Even curve based operations such as planar profile compute safe regions now.


Surface Contouring – When the tool is up against a wall/check, against part check engage/retract is applied.

Tip:In order to get Arc engage/retracts against walls, restrain cuts by check safe clearance, but allow engages to go. Possible with gouge checking off. (ncm5.prt)


Group 1 / 2.5x Operations. Open Vs Closed Engage types Closed areas are regions where the tool cannot drop down in air to reach cut.


OPEN

CLOSED

CLOSED

CLOSED

OPEN

OPEN

OPEN

CLOSED

Difference between planar profile and planar mill with profile pattern. Planar profile follows open engages. Assumes material only on the wall. Planar mill with profile pattern follows closed if blank is specified (assumes material on the floor.) If a blank is not specified, an open engage type is used.

NX does not drop the tool down onto a face be default, even when you use a profile pattern. (We have no clue how much material is really being cut.If you want to see an open area linear engage, you can force your axial engage type to ‘Same as open.’


While computing auto clearance plane..Part/Check is not considered for in planar milling operations. This is fixed in NX6. (block_hole.prt.) Planar milling and profile operations consider part/clamp.


Before NX5, engage angles were measured from the cut. In NX5, a new automatic behavior replaced this. To enable old behavior, starting NX6 two different linear engage types are allowed; Linear(new) and Linear-Relative to Cut(NX4 behavior.

Linear engage with 0 swing angle. (New)


Group 1, Planar Milling. If a region start point is given, NX will use it. If start point is set to mid, the automatic behavior kicks in. Mid point of the closest boundary segment. If start point is set to corner, NX goes to the start point of the boundary specification (starting 5.0.2). (ncm2.prt)


What is effective distance?

Group 1 operation’s pattern start points and pre-drill points could be refined with an effective distance. These user specified points are only effective for regions that are within given effective distance.


Watch out:

Quite a few NCM parameters could be specified using %ToolDia. If you are using Zero diameter tools (Example: Wire EDM) this could result in 0.0 being set to these NCM parameters causing unexpected behavior.


New: Start point alignments.Auto start point alignment is implemented for all group 1 operations. Significant changes in ZL. By default, engages and retracts are lined up and made in the most open areas. In group 1 operations, they are made near the midpoint of outside segments.


Smallest Area to cut. New option under Cavity Milling in 5.0.1.Regions smaller than this are ignored.Use minimum Cut Length in ZL.(ncm3.prt)


Finish Passes and Cutcom.The old Activation Distance parameter is converted to Finish passes.UGII_CAM_NO_CONVERT_ACTIVE_RANGE_TO_FINISH_PASSES = 1 bypasses this behavior. Active only for part conversion.

Finish passes cut walls. No finish passes, no cutcom.Pre NX5, you can not have finish passes/cutcom with zig/zigzag, etc, even if users ask for it. Now you have cutcom on finish passes with all patterns.

Avoid using it with Wall/Island cleanup. Wall and island cleanup options will be incorporated into finish passes in a future release.(ncm1.prt, finish passes.)


Finish Passes and Transfers.

NX4 NX5pre-drill point to the pattern start point.While using cutcom, if the real tool is bigger than the programmed tool, this would scrape the wall of the circular boss.

Predrill points in finish regions are not allowed in NX5. Update: Starting NX5.0.6, pre-drill points in finish regions are allowed.

There is only one cutcom on and one cutcom off. Some of the roughing passes are run with cutcom and some are not

Notice each boss has it’s own ‘finish pass’ with cutcom on and cutcom off. None of the roughing passes are cut with cutcom

Half the machine controllers would throw a signal if the tool path segments between cutcom On and cutcom off self intersect.

No self intersecting loops. This has the highest likelihood of passing all machine controllers.

If the pattern is changed to zigzag, Pre-Nx5 would simply ignore cutcom request.

This works with all patterns including zigzag.


Finish Passes and Transfers

The transfer from the end of one finish pass to the next follows ‘within region transfer’ setting.

If needed, users can get an on cut plane step-over transfer by specifying this ENV. UGII_CAM_PERCENT_TD_MAX_STEPOVER_TRAVERSE

If the transfer distance is less than this, a stepover move will be made.

Starting NX7, this will be controlled by ‘Max Traverse Distance’ parameter.


1) Group 1 – If direct-transfers are used AND the transfer feedrate is 0.0, it is NOW possible that you will get a rapid feedrate and NOT a cut-feedrate.

2) Sequence Control (group2-3) usage in traversal has been obsoleted.

3) Group 2-3, “Custom” approach/departure feedrate has been obsoleted. (NOTE: Custom traversal feedrate has migrated into OPR traversal feedrate which was PREVIOUSLY not supported, so it is covered (However you STILL will get a message is DIFFERENT custom traversal feed-rates were used.))


126. Clearance planes not parallel to tool axis. We use tool axis to reach clearance plane.. perp to tool axis.. Unto 45 degree plane still gives you the same answer.. Past 45, the approach/departure takes the cut plane.(Ncm2.prt)

Initial/Final Engage retracts introduced in Group 1 operations. 5.0.2 Common with group 2 and 3 now.

Initial Final Approach/Departure introduced in Group 1.Supports migration of Clerance plane usage for start only/end only/both.This is still not available in group 2 and 3. Do we need them?

Axial engages. Helix/Ramp on shape Height is calculated from prev depth in group 1. From start point in group 2 and 3. Tool axis is always measured absolute.


Tear-drop engage/retract for hole milling, counter bore milling. With cutcom. Show example. Use point engage instead of pre-drill point. (ncm4.prt) Can we get the point engages to be at the circle center?

Point engages are projected to plane now. In NX4, it was going to the same 3D point.


117. You can now fit an exact helix engage into a circle. Hole milling. It works in NX4, if you say a prayer while processing tool path.


Tool Axis engage takes height from the user. Absolute value used. Different from helix and ramp on shape. (Do we need to change this?) Ramp on shape with 90 degrees ramp angle works as a back-up. (ncm3.prt, minimum_area)

115. Blank plane introduced in 5.0.3By default, blank plane is the first cut level +cut depth.In planar mill, this is specified as blank plane. In Cavity Mill, this is the top of the cut range.You can now use this for transfer for both with regions and final regions.


Regions and Transfer Moves – 2.5x operations.

Going from one depth to the next in a single region in group 1 with out lifting requires, no retract height and axial engage height of 0.0 and Direct transfer. (ncm4.prt)

Currently, all transfers are marked as between regions in 2.5x operations. This will be fixed in NX6.0


Regions and Transfers – Surface Contouring.Region Distance ENV. 300% default. We convert local to within region. If you want local to stay within region, this distance need to be set to your customer preference. (region_distance2.prt)

In NX4, ‘Local’ transfer moves were pattern-dependent and were not consistent.In NX5, all surface contouring operations support ‘With Regions’ and ‘Between Regions’ transfers.‘Within Regions’ or ‘Between Regions’ is decided by the ‘region distance’ parameter.

We convert ‘Local’ transfers in NX4 to ‘Within Regions’ in NX5.If the region distance is smaller than the distance between retract and the next engage, ‘Between Regions’ transfer is implemented. See attached image.

If you get ‘Between Region’ transfer moves where you expected a ‘Within Region’ transfer move, making the region distance bigger would fix the problem.

To make the migration easier, users can set their own preferred defaults for region distance using the following ENV variables.UGII_CAM_NX5_DEF_PERC_REGION_DISTANCE = 5000%UGII_CAM_NX5_DEF_VAL_REGION_DISTANCE = 1000


110. Direct transfer was missing for within regions in 2.5x operations. Introduced in 5.0.2


108. On is considered blank. Tanto is considered wall. Finish passes will work only on tanto. NCM moves can violate On boundaries and not Tan-to boundaries.(ncm3.prt, on_tanto)


107. If you ask for pre-drill points, they will be honored for both open and closed regions. They were only active for closed regions. Effective distance is still honored.

If the pre-drill points are in the “finish regions”, they are ignored.

100. Post commands migration in group 2 and 3.Local – within regionsCheck/default Initial/Final – Between regions – Open questions..

Inherit clearance plane warnings.Should we just follow automatic. Eliminate warnings? GTAC > Eliminate warnings. Switch to auto in MCS if none is specified in MCS in Pre-NX5.


FROM and GOHOME – reintroduced tool axis controls.Working consistently now.

CutcomAvailable in all planar and axial engage types.Available only with finish passes in roughing, profile passes and ZL.Contact Contour available in all cases above.

Positioning of Cutcom statements and how they work.Explain different cases.Helix down, cutcom, minimum move/angle cut.Predrill down, cutcom, go to cut, cut. (Could we introduce minimum move? Or should we leave it up to uses.)Contact contour.


(cutcom.prt)


Follow-region start points in group 1 is now working.How do I sequence group 2 and 3?

Cut Region start points in area milling.Not working.

GRIP and UFUNC of old parameters are migrated to new parameters.UGOPEN/JA works on all new parameters.Recommend going to JA for all new customizations.


Smoothing feed-rate. (ncm5.prt)Move type is set to transfer. You have to set a feed-rate here.Otherwise, machine is going to jerk with short GO moves.

No more custom feed-rates per move types in group 2 and 3.No complaints so far.

Direct transfers on cut plane uses step-over feed-rate.


Tangent arc/linear not working in NX5 due to tolerance issues used to get closed engage types. Now they get deviate upto 10 degrees to force arc/linear engages.(Slot finishing.prt)

Arc Engages back up routine – Full radius, half radius, tool radius. Tool Radius is new.


Currently being worked on..

Performance.

T-Cutters, not yet addressed completely.. Watch out.

Output predrill points not yet working.

Predrill points within finishing region will not be honored.. CAVEAT.

Dumping of NCM parameters in listing window. GTAC wants it.

Tool Axis different from Cut plane not working yet..Do you use it?


Under consideration.

Smoothing in Group 1Initial/Final approach/departure for group 2-3 (5.0.5 or 6)

auto swing on grp 1 linear moves (5.0.5 or 6)

Surface Contouring eng/ret moves to clearance LOST in NX5Regenerative editsNCM contents for Engraving operations to be definedCustomizable NCM dialog items


Getting to blank (UI controlled parameter)

Non-planar clearance geometry(2.5x operations. & MCS)Ramp on Shape Group2-3 : Also Backup to existing moves before plunges occurMove along boundaryHole Making/Wedm/Plunge Milling – New UI.Retract minimum clearance support


Miscellaneous

95. Face milling and Planar Milling operations now contribute to Level Based IPW computation.

Holder_split demo


UGII_CAM_PERCENT_TD_MAX_STEPOVER_TRAVERSE

5.0.5

Point engage – 3d or 2d.ENV variable.


non cutting move update

Documents

g0 moves

departure moves

cut feedrate o rapid

cut feedrate o step

o rapid moves type

approach moves

o linear

return moves