The primary purpose of
MetaCut Finish is to reduce machining and polishing
times on complex molds without sacrificing accuracy. This is
accomplished through the intelligent approximation of lines and arcs or NURBS curves relative to the original point to point data. Additional
features control machine feedrates and exact stop/continuous switching.
As a byproduct, toolpaths are often 60 to 90% smaller than the original.
Arc and line
Finish will automatically produce a highly accurate approximation to an ordered
set of points (and lines) such as commonly found in toolpaths. Separate
tolerances are provided for lines and arcs. These tolerances may be
viewed as the maximum deviation from the original points in the file. In
addition to maintaining a tolerance to the original points, a maximum
deviation from the original lines is also maintained.
Arcs may be fit in one of
three methods: 1) relative to the standard orthogonal planes (XY,XZ,YZ).
2) relative to any rotation of the standard orthogonal plane. 3) to
completely arbitrary planes (3D arcs). Almost all controls will machine
arcs using the first method, some controls will allow method number 2,
and a few controls are able to machined true 3D arcs. (*note- a 3D arc
is not a helix).
will always fit the most appropriate entity. If any set of data falls
within tolerance for both a line and an arc, MetaCut Finish
will only produce the entity with the closest fit. MetaCut Finish also has user defined limits for largest and smallest
arc radius as well as the smallest distance between arc endpoints and
smallest arc length. All settings may be saved to a named parameter set
which may be loaded at any time while in MetaCut Finish.
The NURBS curve fitting
available as an option for MetaCut Finish produces
both small and accurate files for use with controls which support true NURBS machining. The benefits of this technology include very smooth
finishes similar to the arc fitting, but with absolutely no dependence
on planes as there is on most controls with arcs. In addition the
control will prevent overtravel of the machine tool when using NURBS
machining. The NURBS machining also produces good results with true 3D
toolpaths such as "flowline" type toolpaths.
NURBS machining is the next
step forward in complex mold machining.
is able to continuously vary the feedrates while your part is machining.
This feedrate adjustment is easily adjusted by the user for optimal
feeds on different machine tools. Feedrate adjustments are used to
prevent following error while simultaneously decreasing your machining
times. By changing the feedrates of individual arcs MetaCut Finish will machine large arcs at high feedrates while slowing
down for small radius arcs.
Exact stop /
With the greatly increased
feedrates available when machining using MetaCut Finish,
sudden changes in tool direction can produce overtravel. MetaCut Finish will set your machine to exact stop mode (come
to a stop at the endpoint) whenever the change in direction exceeds a
user defined angle. When the toolpath becomes smooth again your machine
will be set back to continuous mode (keep moving through the endpoints).
This feature combined with the "automatic feedrate modification" feature
will help to maintain accuracy while still allowing your machine to
travel at the highest possible feedrates for any given situation.
Import / Export and
the TOOL language
Northwood Designs, Inc. has
developed a complete language similar in syntax to the C language but
with specialized abilities which are particularly useful for the
manipulations of the types of files commonly found in the CAD/CAM
industry. This language is available to the end user and may also be
used to make custom programs.
Import and export of files is
handled in two ways within MetaCut Finish. Many
common formats are "hard coded" to allow for quick I/O. With the first
release, MetaCut Finish will support ASCII, DXF, G&M codes, and
Mastercam NCI as hard coded formats. These will
not be complete import/export filters but will instead support the types
of entities which will be commonly used in MetaCut Finish.
These include lines, arcs, and NURBS curves. We expect support for
additional entity types to be added as necessary. The second type of
import/export is the "custom" engine. These filters use the TOOL
language and are completely customizable. This gives the product the
ability to import file formats that are not included with the base
package. You can also modify existing filters.
There is a full featured batch
language which allows the user to run the product from a batch file over
a network. The batch language allows for the loading of multiple files
which may be optimized using different parameters, then exported with
different export filters. All unattended. This is useful for running
multiple conversions of large files overnight or for running across a
Unlimited undo (limited only by your
You may save an unlimited number of
default settings for different machine tools or uses.
The primary toolset is greatly
simplified and combined into a dragable toolbox, the most commonly
used features are always close at hand.
Things to keep in mind when
considering MetaCut Finish
MetaCut Finish was
not designed to fit arcs to your old toolpaths. The best results are
obtained with new files made with the process in mind. You can use
MetaCut Finish with old files but the results may not be as
Best results are obtained with higher
precision files, this usually means 6+ numbers after the decimal point
in the original file. MetaCut Finish can format and truncate all data on
Your original file should be run to
small chordal deviations for best results. MetaCut Finish
will actually return a smaller file from a highly defined large
original file than it will from a coarsely defined small original
Northwood Designs, Inc. stands behind each
of their products. Most problems are quickly identified and solutions
offered at the time of the call.
We have a policy of fixing any problems
which reduce the functionality of the product immediately. Customer
satisfaction with our products is paramount.