3-Axis Mill
This section covers setup requirements for operations on the following GCD types:
When operations are alternatives of each other, the operations are listed in the order in which they are considered by aPriori (the order in which they are listed in the template).
Note that, as described below, 3-Axis Mill feasibility rules take into account whether the current GCD is part of a parallel surface chain (PSC). See Parallel Surface Chain.
Parallel Surface Chain
A parallel surface chain (PSC) consists of a closed loop of planar faces and curved walls that are all parallel to each other in the following sense:
o The rules of a PSC’s curved walls all run in the same direction.
o Each planar face of a PSC contains lines that are co-directional with rules of the PSC’s curved walls.
See also PSCs and Perimeters.
It is often possible (and desirable) for all the surfaces of a PSC to be side milled using a single setup. Therefore, aPriori takes PSCs into account when activating setup axes and evaluating the feasibility of operations on planar faces and curved walls:
• For a curved wall that is part of a PSC, if no active setup axis makes it accessible to side milling, aPriori activates a setup axis that makes the surface accessible to side milling, assuming side milling is otherwise feasible for the surface.
• In passes 1-3 (see Operation Assignment for Machining), Rounding and Filleting are infeasible for a curved wall that is part of a PSC.
• For a planar face that is part of a PSC, if no active setup axis makes all the PSC’s surfaces accessible to side milling, aPriori activates a setup axis that makes all the surfaces of the PSC accessible to side milling, assuming side milling is otherwise feasible for the surface.
• In passes 1-3 (see Operation Assignment for Machining), Facing is infeasible for a planar face that is part of a PSC, provided that it is accessible to side milling from some candidate setup axis and has no sharp corners that are inaccessible from that setup axis.
Planar Face
• Facing: setup axis must provide access to the GCD from a direction normal to the GCD.
If the operation is part of a multi-approach operation sequence (which is considered only after single-approach finishing has been found infeasible--see Multiple Approach Surface Finishing), use an activated setup axis that provides obstructed access to at least 2.5% of the GCD, if one exists.
If the operation is not part of a multi-approach operation sequence and if the process setup option Machining Automation Level is set to Semi Automated, check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD fully accessible, the operation is infeasible.
If the operation is not part of a multi-approach operation sequence and the process setup option Machining Automation Level is set to Fully Automated, and the planar face is not part of a PSC (see Parallel Surface Chain), check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD fully accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations (except multi-approach operations) for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If no activated setup axis would (if used) render the GCD fully accessible, check the following condition:
o The GCD’s surface area is a sufficiently large fraction of the total surface area of the part (as specified by the cost model variable fractionalAreaSetupTrigger)
If the condition is met, activate a setup axis that would (if used) render the GCD fully accessible, if one exists.
Otherwise, use an activated setup axis that provides acess to at least 99% of the surface (in this case, aPriori assumes the use of a tool that can slide under a small undercut, such as a reduced shank mill).
Otherwise the operation is infeasible.
If the process setup option Machining Automation Level is set to Fully Automated, and the planar face is part of a PSC, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check all activated setup axes.
If no activated setup axis would (if used) render the GCD fully accessible, check the following condition:
o The GCD’s surface area is a sufficiently large fraction of the total surface area of the part (as specified by the cost model variable fractionalAreaSetupTrigger)
If the condition is met, activate a setup axis that would (if used) render the GCD fully accessible, if one exists.
Otherwise the operation is infeasible.
• Side milling: setup axis and GCD must be parallel.
If the operation is part of a multi-approach operation sequence (which is considered only after single-approach finishing has been found infeasible--see Multiple Approach Surface Finishing), use an activated setup axis that provides obstructed access with access to at least 2.5% of the surface, if one exists.
Otherwise, if the process setup option Machining Automation Level is set to Semi Automated, check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD fully accessible, the operation is infeasible.
If the process setup option Machining Automation Level is set to Fully Automated, and the planar face is not on a PSC (see Parallel Surface Chain), check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD fully accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If no activated setup axis would (if used) render the GCD fully accessible, check the following condition:
o The GCD is a wall of a complex hole whose contours lie in parallel planes and whose walls are normal to these planes.
If the condition is met, activate a setup axis that would (if used) render the GCD fully accessible, if one exists.
If the condition is not met, check the following condition:
o The GCD’s surface area is a sufficiently large fraction of the total surface area of the part (as specified by the cost model variable fractionalAreaSetupTrigger)
If the condition is met, activate a setup axis that would (if used) render the GCD fully accessible, if one exists.
Otherwise the operation is infeasible.
If the process setup option Machining Automation Level is set to Fully Automated, and the planar face is on a PSC, check the following setup axes to see if the render fully accessible all surfaces on the PSC:
o Principal
o User-activated
If none would (if used) render all the PSC’s surfaces fully accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for PSC:
o All activated (non-principle, non-user-activated) setup axes
If no activated setup axis would (if used) render the PSC’s surfaces fully accessible, activate a setup axis that would (if used) render all the PSC’s surfaces accessible to side milling.
If no setup axis would render all the PSC’s surfaces fully accessible, check all activated setup axes to see if one would make the current planar face accessible to side milling. If there is none, check the following condition:
o The GCD’s surface area is a sufficiently large fraction of the total surface area of the part (as specified by the cost model variable fractionalAreaSetupTrigger)
If the condition is met, activate a setup axis that would (if used) render the GCD fully accessible.
Otherwise the operation is infeasible.
• Contouring: setup axis must be oblique (unobstructed) to the GCD.
Check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none would (if used) render this GCD accessible, the operation is infeasible.
• General mill finishing: This operation’s setup requirements are always considered feasible.
Check for the existence of the following setup axes in this order:
o Principal perpendicular unobstructed
o User-activated perpendicular unobstructed
o Principal perpendicular obstructed
o User-activated perpendicular obstructed
o Principal parallel unobstructed
o User-activated parallel unobstructed
o Principal parallel obstructed
o User-activated parallel obstructed
If none exists, use the primary setup axis.
• Undercut milling: This operation is never auto-evaluated; it must be explicitly user-included. This operation’s setup requirements are always considered feasible. The setup axis is preferred be parallel obstructed to the GCD.
Check the following setup axes in the following order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
• Chamfer milling: This operation is never auto-evaluated; it must be explicitly user-included. The operation’s setup requirements are always considered feasible.
• Mill grooving: This operation is never auto-evaluated; it must be explicitly user-included. The operation’s setup requirements are always considered feasible.
• Rough milling: This operation’s setup requirements are always considered feasible.
Check for the existence of the following setup axes in this order:
o Principal perpendicular unobstructed
o User-activated perpendicular unobstructed
o Principal perpendicular obstructed
o User-activated perpendicular obstructed
o Principal parallel unobstructed
o User-activated parallel unobstructed
o Principal parallel obstructed
o User-activated parallel obstructed
If none exists, use the primary setup axis.
Curved Wall
• Indirect filleting: setup axis must be normal to the GCD in such a way that this fillet can be produced by the corner of the tool.
If the curved wall is not part of a PSC (see Parallel Surface Chain), check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none would (if used) render this GCD accessible, the operation is infeasible.
If the curved wall is part of a PSC, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check all activated setup axes. If none would (if used) render the GCD accessible, the operation is infeasible.
• Rounding: setup axis must be oblique (unobstructed) to the GCD.
If the curved wall is not part of a PSC (see Parallel Surface Chain), check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none would (if used) render this GCD accessible, the operation is infeasible.
If the curved wall is part of a PSC, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check all activated setup axes. If none would (if used) render the GCD accessible, the operation is infeasible.
• Side milling: setup axis and GCD must be parallel (unobstructed).
If the operation is part of a multi-approach operation sequence (which is considered only after single-approach finishing has been found infeasible--see Multiple Approach Surface Finishing), use an activated setup axis that provides obstructed access with access to at least 2.5% of the surface, if one exists.
Otherwise, if the curved wall is not part of a PSC (see Parallel Surface Chain), check the following setup axes:
o Principal
If neither would (if used) render this GCD fully accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle) setup axes
If no activated setup axis would (if used) render the GCD fully accessible, the operation is infeasible.
If the curved wall is on a PSC, check the following setup axes to see if the render fully accessible all surfaces on the PSC:
o Principal
If neither would (if used) render all the PSC’s surfaces fully accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for PSC:
o All activated (non-principle) setup axes
If no activated setup axis would (if used) render the PSC’s surfaces fully accessible, activate a setup axis that would (if used) render all the PSC’s surfaces fully accessible to side milling.
If no setup axis would render all the PSC’s surfaces fully accessible, check all activated setup axes to see if one would make the current curved wall fully accessible to side milling. If there is none, the operation is infeasible.
• Contouring: setup axis must be oblique (unobstructed) to the GCD.
Check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none would (if used) render this GCD accessible, the operation is infeasible.
• General mill finishing: This operation’s setup requirements are always considered feasible.
Check for the existence of the following setup axes in this order:
o Principal parallel unobstructed
o User-activated parallel unobstructed
o Principal parallel obstructed
o User-activated parallel obstructed
o Principal oblique unobstructed
o User-activated oblique unobstructed
If none exists, use the primary setup axis.
• Undercut milling: This operation is never auto-evaluated; it must be explicitly user-included. This operation’s setup requirements are always considered feasible. The setup axis is preferred to be parallel obstructed to the GCD.
Check the following setup axes in the following order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
• Rough milling: This operation’s setup requirements are always considered feasible.
Check for the existence of the following setup axes in this order:
o Principal parallel unobstructed
o User-activated parallel unobstructed
o Principal parallel obstructed
o User-activated parallel obstructed
o Principal oblique unobstructed
o User-activated oblique unobstructed
If none exists, use the primary setup axis.
• Thread milling: setup axis must be parallel (unobstructed) to the GCD.
Check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none would (if used) render this GCD accessible, the operation is infeasible.
Curved Surface
• Indirect filleting: setup axis must be normal to the GCD in such a way that this fillet can be produced by the corner of the tool.
Check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none would (if used) render this GCD accessible, the operation is infeasible.
• Rounding: setup axis must be oblique (unobstructed) to the GCD.
Check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none would (if used) render this GCD accessible, the operation is infeasible.
• Contouring: setup axis must be oblique (unobstructed) to the GCD.
Check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none would (if used) render this GCD accessible, the operation is infeasible.
• General mill finishing: This operation’s setup requirements are always considered feasible. The setup axis is preferred to be oblique (unobstructed) to the GCD.
Check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none exists, use the primary setup axis.
• Rough milling: This operation’s setup requirements are always considered feasible. The setup axis is preferred to be oblique (unobstructed) to the GCD.
Check the following setup axes in this order:
o Principal
o User-activated
If none would (if used) render this GCD accessible, come back later to the feasibility check for this GCD and operation, if necessary. For now, move on to other operations for this GCD and then to operation assignment for all the other GCDs. Then, if the GCD remains unassigned, check the following setup axes for this GCD:
o All activated (non-principle, non-user-activated) setup axes
If none exists, use the primary setup axis.
• Chamfer milling: This operation is never auto-evaluated; it must be explicitly user-included. The operation’s setup requirements are considered feasible, if the GCD is a ruled curved surface (that is, if the surface could be generated by translational and rotational motion of a line segment through space).
Simple Hole
All 3-axis mill operations on simple holes employ a setup axis that is parallel (obstructed or nonobstructed) to the hole’s axis of symmetry. Feasibility checks proceed as follows:
If the process setup option Machining Automation Level is set to Semi Automated – principle setups only, check the following setup axes in this order:
• Principal unobstructed
• User-activated unobstructed
• Principal obstructed
• User-activated obstructed
If none would (if used) render the GCD accessible, consider the operation infeasible.
If the process setup option Machining Automation Level is set to Fully Automated, check the following setup axes in this order:
• Principal unobstructed
• User-activated unobstructed
• All activated non-obstructed
• Un-activated unobstructed
• Principal obstructed
• User-activated obstructed
• All activated obstructed
• Un-activated obstructed
If an un-activated setup axis would (if used) render the GCD accessible, activate it (assuming the operation is otherwise feasible). If none of the above setup axes would (if used) render the GCD accessible, consider the operation infeasible.
Note that Step Drilling (manually selected) is also supported for multistep holes. The drill is step-shaped and creates an entire multistep hole in a single operation. Step Drilling is very productive when many multistep holes must be cut.